Working With The Emission Database (EDB) Brochure

Volume 1 Airviro User´s Reference Working with the Emission DataBase (EDB) How to construct a dynamic emission database and simulate emission scenarios Working with the Emission DataBase How to construct a dynamic emission database and simulate emission scenarios Amendments Version Date changed Cause of change Signature 3.11 July 2007 Upgrade to Airviro version 3.11 GS 3.12 Jan 2009 Upgrade to Airviro version 3.12 GS 3.13 Jan 2009 Upgrade to Airviro version 3.13 GS 3.20 April 2010 Upgrade to Airviro version 3.20 GS Contents 3.1 Introduction: What it is All About ....................................................................... 5 3.2 Getting started ..................................................................................................... 8 3.2.2 Selecting the EDB to Work with ..................................................................................... 9 3.2.3 Altering Subwindow Texts .......................................................................................... 11 3.2.4 Adding Substances to the Substance List ................................................................... 12 3.2.5 Substance Groups in the EDB ..................................................................................... 13 3.2.6 Choosing a Geographical Area .................................................................................... 14 3.2.7 Notes on Filling in Tables in the Edb ............................................................................ 16 3.3 Point sources in the EDB .................................................................................. 17 3.3.1 What is a Point Source? .............................................................................................. 17 3.3.2 General Principles ....................................................................................................... 17 3.3.3 Dynamic Emission: Formulae for Time Variation and Temperature Effects.................. 18 3.3.4 Static Emission Information ......................................................................................... 22 3.3.5 Specifying a Point Source Based on Yearly Total Emission Figures ............................ 23 3.3.6 Emission Simulation from a Point Source .................................................................... 26 3.3.7 Introducing a Point Source Based on Knowledge About the Emission Process ........... 30 3.3.8 Using Search Keys and Pattern Matching Facilities as Search Conditions .................. 33 3.3.9 Saving your search criteria and output settings ........................................................... 35 3.4 Area Sources in the EDB .................................................................................. 36 3.4.1 What is an Area Source? ............................................................................................. 36 3.4.2 General Principles ...................................................................................................... 36 3.5 Grid Layers in the EDB ...................................................................................... 37 3.5.1 What is a Grid Layer? ................................................................................................ 37 3.5.2 General Principles ...................................................................................................... 37 3.6 Traffic Emissions in the EDB ............................................................................ 39 3.6.1 What is a Road source? ............................................................................................. 39 3.6.2 General Principles ...................................................................................................... 39 3.6.3 Introducing Emission Factors for Vehicles .................................................................. 41 3.6.4 Naming Standard for Emission Factors ...................................................................... 42 3.6.5 Introducing Road Types ........................................................................................ 43 3.6.6 Introducing Traffic Information in the EDB .................................................................. 44 3.6.7 Emission Simulation with Road Sources and Restrictions .......................................... 46 x 3.7 Grid Presentation of Emissions....................................................................... 48 3.8 Creating EDB Reports and displaying the Database Structures .................. 50 3.9 Creating Noise Reports .................................................................................... 52 Appendix 1A: Suggested Substance List ............................................................. 53 1A.1 Inorganic Gaseous Substances (1-39) ......................................................................... 53 1A.2 Particulate (Inorganic, Nonmetallic) Substances (40-49).............................................. 53 1A.3 Metals (50-69) ............................................................................................................. 54 1A.4 Organic substances (not halogens) (70-179) ............................................................... 54 1A.5 Halogenic Organic Substances (180-249) ................................................................... 55 1A.6 Others (250- ) .............................................................................................................. 56 Appendix 1B: Mathematical Definitions of the Formulae Used in the EDB ....... 57 1B.1 Point, Area and Grid Source Emissions ....................................................................... 57 1B.2 Road Source Emissions............................................................................................... 58 1B.3 Normalisation of Formulae in an EDB .......................................................................... 59 1B.3.1 Sources where the emission variation is not dependent on ambient air temperature variations60 1B.3.2 Sources where the emission variation depends only on ambient air temperature .................... 60 1B.3.3 Emissions described by maximum effects (fuels) ...................................................................... 61 Appendix 1C: Structure of an EDB ........................................................................ 62 Working with the Emission Database (EDB) April 2010 Page 5(62) 3.1 Introduction: What it is All About A Database, Which Also Includes a Sophisticated Simulation Tool The Airviro emission database (EDB) is not only a database. In fact the main emphasis has been placed on the user interface, the simulation models and the output facilities. A diagram explaining the structure of the EDB can be found in Appendix 1C: Structure of an EDB. How does EDB client work? Airviro has is a web based user interface. Airviro can be used from a PC or any other device running Internet Explorer 6 or later and Firefox. After logging in on Airviro the EDB module can be selected. All data processing is made on the Airviro server and the results are transferred to the web browser. Please note that JAVA JRE (run time plugin) must be installed and enabled in the web browser. The EDB includes tools for management and administration of the emission sources. A Structured Way of Storing Emission Data The tables provided enable you to describe: Emission from Point sources - all the emission is concentrated in a very small area, such as a chimney or stack. Information describing the stack conditions must be given for use in the Dispersion models. Area sources - emission is evenly distributed over a rectangular area and is assumed to leak out. Road sources - the emission is assumed to be evenly distributed over a line. This is normally used as an approximation for road traffic. Grid layers - background emission levels can be defined in the form of grids. Time and temperature variation of emission Different road types describing traffic patterns Vehicle characteristics and speed-dependent emission factors as well as other features that help you to convert obtainable information into emission figures. Simulating ”What Happens If...” Scenarios Once you have started filling in your EDB with data, you will appreciate the ability to search for emission. The search facility allows you to specify exactly what sources you are interested in finding out the emission from, especially if you have created your EDB in a structured way. You can search using combinations of the following restrictions: Airviro version v3.20 Page 6(62) April 2010 Source name and information strings Point, area, road or grid sources, or a combination One or several fuel types, substance groups and formulae One or several road types and vehicle types Congestion vehicle and speed Any combination of search keys A restricted area of the map Restrictions on time an temperature Using the search keys you will be able to find out emission figures such as: The total emission of SO2 from heating plants at 6 o’clock in the morning The contribution to the total NOx emission of heavy vehicles in the city centre at rush hour The emission of toluene from paint spraying industries in the northern part of the town when the outside temperature is over 20 degrees In this chapter a number of examples and recommendations on how to use the EDB software will be presented. If you follow the recommendations you can easily simulate the consequences of hypothetical situations such as: What would happen if heavy vehicles were removed from the city centre? What would be the effect of changing the speed limit on the main roads? What reduction of emission could be expected if low sulphur oil was introduced? Integration with Dispersion Models Within the Airviro environment, the dynamic EDB is directly linked to the dispersion models, allowing you to combine different emission scenarios with various dispersion conditions. Given the weather and the parts of the day or year that you are interested in, relevant emissions will be used as input data to the dispersion calculation. In the Airviro User’s Reference, Volume 4: Working with the Dispersion Module, you will find examples on how to utilise the EDB for dispersion simulations. The Report Generator The report generator or Output can be used to extract information from the EDB for presentation on the screen, storage in a file or as a printout. You can obtain selected static data such as source locations and emission factors, as well as time dependent information concerning emission loads for a given period and area. Also, you can obtain a standardized output for road noise emission levels (colour-coded range). This output can be configured for source, grid, noise and report (only ASCII Text). You can produce reports in different formats (GIF, PDF and ASCII Text) for being used with other applications. Working with the Emission Database (EDB) Swedish Meteorological and Hydrological Institute, SE-601 76 Norrköping, Sweden Page7(62) Phone: +46-11-495 8000, Fax: +46-11 495 8001 How to Collect the Relevant Information to be Stored in the EDB Normally when you work with the EDB we recommend that you initially collect information directly from industry, local authorities, etc. and store the information in the EDB. If you work through the examples in this chapter you will be able to design suitable questionnaires. Later on, you should be able to carry out dispersion calculations based on the EDB for historical periods and compare the results with measured ambient data. By simulating different wind directions and weather conditions you have a good chance of identifying sources that are not properly described in the EDB. Try to correct the emission data by collecting new information. If this method does not improve the results, we recommend that you use the Receptor Model to estimate emissions (Dispersion Module) When you are satisfied with the historical simulation results based on the EDB, you are ready to work with real time dispersion applications (now casting) or forecasts for the next 24 hours. Airviro version v3.20 Page 8(62) April 2010 3.2 Getting started After logging in the application by entering a username and password (Figure 3.2.1), the user is presented with a list of all available Domains (if none has being previously selected and stored), By selecting a Domain the top menu list will be refreshed to show all available Airviro Modules. See Figure 3.2.2 Figure 3.2.1 Logging Airviro Figure 3.2.2 Select Domains In this section you will learn how to set up the EDB module so that it is ready to use. This includes: Selecting an EDB to work with - either the global EDB or a personal EDB Creating a new personal EDB by either copying another EDB or by copying the empty EDB Customising some of the menu texts Adding new substances to the substance list Creating substance groups Working with the Emission Database (EDB) Swedish Meteorological and Hydrological Institute, SE-601 76 Norrköping, Sweden Page9(62) Phone: +46-11-495 8000, Fax: +46-11 495 8001 Working with the map Some of the examples shown here are based on real sources from the Airviro (Göteborg) Reference System, included in all delivered Airviro systems. 3.2.2 Selecting the EDB to Work with After EDB is selected among the available modules on the top list, the EDB module will be opened and a new list of options or submenus will appear on the left side of the window. When working with Edb, you will be able to make new emission databases or to edit existing ones. If you decide to make a new one, then it may be convenient to copy and rename an existing database and then making the necessary changes. Start your session by selecting an Edb, clicking the option User&Edb in order to open this menu (Figure 3.2.2.1). There are two list boxes labelled User and Edb. If you click on global in the list box to the left and then press the Apply button, it means that you have chosen to work with the global EDB. The Description textbox can be used to describe the contents of the database. You can add a description to the Edb by entering some text and pressing the button “Save Description”. Figure 3.2.2.1 Select user and Edb Note: A global EDB is the official, original emission database in the system consisting of formulae, emission factors and emission figures that should be approved and supported by the system manager. Usually, no one but the system manager should be able to edit the global EDB. However, any user can examine the contents of the global EDB or make a copy, rename it and then edit and change its content. Airviro version v3.20 Page 10(62) April 2010 Note: It is possible to set up privilege levels in the Airviro system so that different users can have different privilege levels for different emission databases. It should be the task of the system administrator to make sure that the global EDB can only be edited by responsible persons and that other users can make their own personal copies of the global EDB if needed. It is not only the global EDB that can be protected in this way. Privilege levels can also be set up for a user’s personal EDBs. If you have trouble accessing an existing EDB that you think you should be able to access then ask your system administrator about your privilege levels. Creating a New Copy of the Global EDB Normally, you are not allowed to edit the global EDB, so we suggest that you make your own copy. Click on Edb again under Copy and click in the left box on your user identity. Your user identity is the same name as you typed when you logged in to the computer. Your personal Edb will be shown in the list box on the right hand side. You create your own copy of the global EDB by clicking on the push-button Copy to the right. A subwindow named New Edb appears. See Figure 3.2.2.2. Type a suitable name in this subwindow. Confirm by clicking OK. You now have a new copy of the global EDB. The new name appears in the right list box. Figure 3.2.2.2 Add new Edb and Copy Creating a Copy of Someone Else’s Personal EDB The Edb subwindow: Select the Edb you want to copy by clicking on it, and then clicking on Copy The New EDB subwindow will appear. Enter a name for your copy in the text field. See Figure 3.2.2.2. Click on OK. Check that you have received a copy under your own user identity, with the name that you typed. Note: It is even possible to set privileges on individual EDBs so that other users cannot even view them or copy them. This is done in the privilege level file, which should be maintained by the system administrator. Deleting a Edb Working with the Emission Database (EDB) Swedish Meteorological and Hydrological Institute, SE-601 76 Norrköping, Sweden Page11(62) Phone: +46-11-495 8000, Fax: +46-11 495 8001 You can easily delete any one of your own personal Edb Within the User & Edb subwindow: Click on the personal Edb that you want to delete and then click on Delete The Question sub-window will appear. Confirm or cancel your order. Note: It is usually only possible to delete your own personal Edb. If you choose a personal EDB owned by any other user, or the global EDB, then the Delete button will be disabled. The ability to be able to delete other Edb´s can however be configured in the privilege level file which should be maintained by the system administrator. Creating a New Empty EDB Within the User & EDB subwindow: Click on Add new empty The New EDB subwindow will appear. Type the desired name for your copy beside Name. See Figure 3.2.2.2. Click on OK. You have now created an empty Edb. Exercise 3.2.2.2 Create an empty personal EDB with the name: My_first_EDB. Check and repair EDB ( only version 3.13) Click on Check edb if you want the system to check the consistency of a personal EDB. Click on Repair edb if you want the system to repair a personal EDB. 3.2.3 Altering Basic Settings Texts Select your personal Edb: My_first_EDB, which should be empty. This EDB has been created with default texts but it is possible to alter some of them. You should only alter texts in an empty EDB, that is before you start entering data, because these texts will apply to every single source in the EDB. For looking at the currently defined texts, select Basic Setting under the Subtables menu. Here you will see a list of texts that can be defined by the user: Scenario texts, Speed texts, Temperature texts, Searchkeys, activity codes, geographical codes and Units.. Choose one of them, for example Scenario.... A subwindow appears showing the default scenario definitions - consecutive years starting from the year 2003. But what if you have emission estimations for Airviro version v3.20 Page 12(62) April 2010 the year 2015? To be able to incorporate these figures into your EDB, change one of the scenarios (e.g. change scenario 10) to 2015. Now, whenever you enter or edit a source, the year 2015 will appear in the scenario list in the 6th position. See Figure 3.2.3.1. Figure 3.2.3.1.Basic Setting You can alter the speed and temperature texts too, as they have been set up to comply with Swedish traffic (i.e.) and weather conditions but might not be so relevant to other countries. 3.2.4 Adding Substances to the Substance List Select the global EDB. This contains the default list of substances, which is also used for all local Edb. To examine the substance list: Click on Subtables Select Substances... Working with the Emission Database (EDB) Swedish Meteorological and Hydrological Institute, SE-601 76 Norrköping, Sweden Page13(62) Phone: +46-11-495 8000, Fax: +46-11 495 8001 Figure 3.2.4.1 Substances Note: There is only one substance list shared by the global EDB and all local Edb´s. The list can only be changed in the global EDB, so you must have edit privileges for the global EDB if you want to make changes to the substance list. WARNING: The Edb does not recognise the substance name that you write in the substance list. It looks for the position, which means that there are 1023 substances with internal names: 1 to 1023. Later, when you define a source of emission you have to define what substances are emitted from that source by pointing in the substance list at the position where you have written the desired substance name. If you then change substance names between positions in the substance list, you have to redirect the pointer from all sources to the correct positions in the substance list. Consequently, you should set up the substance list as completely as possible before you start to fill the Edb with information. 3.2.5 Substance Groups in the EDB In several applications it would be convenient to define substance groups as a specific mixture of substances defined in the substance list. If you define a substance group called standard petrol, and define the percentage of different hydrocarbons, lead, etc. this would simplify and structure your work later on when you are to define all sources emitting gases from standard petrol or if the composition of standard petrol needs to be changed. To define a substance group: Select the Subs. Group submenu in the Subtables menu to the left The Substance groups subwindow appears, then press the Add button. Type a name for the new substance group in the text field Name. A list of substances will be presented as in the figure, and is also included in the appendix. If you use the scroll bar to the right you will find out that there are 1023 positions for different substances. These are grouped in categories depending on the type of chemical substance. This substance list has been adopted by several Airviro installations. We recommend that you do not change the positions of existing substances, but you may introduce any new substances at free positions in the substance list. Airviro version v3.20 Page 14(62) April 2010 From the substance list, choose the individual substances by clicking on them. (Keep Shift or Ctrl key pressed to select more than one item). Then confirm your choice by clicking on the arrow button. In Data enter the weight percentage of the individual substances in the text area in the list box: Emission (%) Confirm your choice by clicking Apply. The choice is saved when the legend “setting saved” appears. The example above shows a substance group that has been created to describe hydrocarbon emission from vehicles and is a particularly illustrative example of how substance groups can be used. Many different hydrocarbons are emitted from combustion of petrol, and we have details about a few of them. The substance group consists entirely of hydrocarbons from petrol, therefore we enter 100% for the substance HC Traffic. However contained in HC Traffic we know there are about 4% benzene, 12% toluene and 13% total xylenes. We can link the description of hydrocarbon emissions from cars to this substance group instead of just to the substance HC Traffic. In this way we have the option of searching for either total hydrocarbon emission or for one of the individual hydrocarbons. Figure 3.2.5.1 The substance group subwindow Exercise 3.2.5.2 Define a substance group called Standard Petrol consisting of 5% Benzene, 12% Toluene and 3% P-Xylene. 3.2.6 Choosing a Geographical Area Selecting a Map Working with the Emission Database (EDB) Swedish Meteorological and Hydrological Institute, SE-601 76 Norrköping, Sweden Page15(62) Phone: +46-11-495 8000, Fax: +46-11 495 8001 Some systems have several maps within Airviro. You can choose between maps in the Source subwindow by using the option button the Figure 3.2.6.1. Some systems have several maps within Airviro. You can choose between maps. For example in this figure is select Gothenburg. Figure 3.2.6.1. Map Selecting a Geographical Subarea Within a Map When you have selected a map, it is possible to zoom in the map: Click on the Zoom In button in the map area. (Figure 3.2.6.1.) . A white hair cross will appear when you move the mouse pointer onto the map. Move the hair cross to a geographical point that you want to define as a corner in the zoomed area. Click on the left mouse button and drag the mouse to stretch a rectangle. Release the mouse button when you are satisfied with the marked area. The chosen subarea will be redrawn on the screen. Note: As the map is vector based, you can zoom again in the zoomed area. However the resolution in the zoomed area will usually not be better than in the original map. There are two exceptions: the road network and the visual effects of having more picture elements on the screen per square metre of the geographical area. There is also a limit of how small an area can be zoomed into. To Restore the Maximum Area Map If you have zoomed in your map and would like to display the original (maximum) size of the map, then click on the push button Whole in the map dialogue area (button up the map) To restore the last Zoom Area Map If you have zoomed in your map and would like to display the last size of the map, then click on the push button Zoom Out in the map dialogue area. Pan I you have zoomed in your map and would like to display the other area map with the same scale, then click on the push button Pan in the map dialogue area. To Clear a Map If you have displayed emission information on top of the map you can always clear the map area (displaying only the map) by clicking on the push button Clear in the map dialogue area. Airviro version v3.20 Page 16(62) April 2010 3.2.7 Notes on Filling in Tables in the Edb When entering data into an EDB you will often come across large tables that have to be filled in with emission factors. It is very important that there are no extra spaces in the table. By default, tables are created with the value 100 in each cell. Working with the Emission Database (EDB) Swedish Meteorological and Hydrological Institute, SE-601 76 Norrköping, Sweden Page17(62) Phone: +46-11-495 8000, Fax: +46-11 495 8001 3.3 Point sources in the EDB In this section you will learn the basic ideas behind entering point sources in the Edb. The emission from a point source can be defined in one of three ways: 1. By defining the total amount of each substance emitted in a year 2. By defining the total amount of a substance group emitted in a year 3. By linking the source to a fuel and defining its maximum effect The following steps will be explained: Information required when entering a point source Time and temperature variation formulae Static information needed for dispersion modelling Using the search conditions to find out emission figures from your source Creating a fuel type Defining a point source based on fuel consumption 3.3.1 What is a Point Source? If the air pollutants are emitted from a well defined position a small restricted volume then we define the source as a point source. An emitting stack or chimney is a typical point source. In the Edb, you can describe the effect of heat and momentum fluxes on point source emissions, i.e. information that is necessary in order to make realistic dispersion simulations from a stack. 3.3.2 General Principles When adding a point source to the Edb the following information must be given: Name information gives the name of the source plus two information strings. These strings can be used as search conditions when searching in the EDB. General information such as the name of the company, address, contact person, etc. This information is needed to maintain the database. Airviro version v3.20 Page 18(62) April 2010 Dynamic information is the information that directly controls the emission, such as formulae that describe the emission as a function of outdoor temperature or as a function of day type and hour. Static information such as chimney height, exhaust gas temperature, coordinates, etc. These figures do not affect the emission strength, nor do they vary over the year, but they are required in order to describe the exact location of the initial pollutant plume. This type of information is vital for the dispersion simulations. Emission from the source either directly in terms of the substances emitted, or linked to a substance group or fuel type. It is also possible to link the emission to a Indico Presentation macro. Instead of specifying the emission for a substance it is possible to select a macro.. A macro must be previously defined in Indico Presentation. The unit of the resulting time series from the macro must be g/s. Search keys - it is possible to define five groups of search keys in order to structure the pollution sources into groups that can be used to separate the total emissions. The first two groups have space for 128 search keys each and the other three groups have space for 32 search keys. 3.3.3 Dynamic Emission: Formulae for Time Variation and Temperature Effects Before giving any general or static information it is important to create a formula that describes the typical variation of the emission. In most cases of emission within a large city we know that the variation of emission is of the same order of magnitude as the long-term average emission. If you start with an empty Edb there is one default formula in the system, the so-called STANDARD formula that contains a time constant emission and no temperature dependency. The emission variations defined in the formula tables are interpreted in two principal ways as a consequence of linking either a substance, a substance group of a fuel to a formula: Substance, substance group: yearly variation is given as absolute values but all other variations are normalised Fuel: all variations are given as absolute values We will begin by considering the first group as this expresses a more general formulation of emission variations. In 3.3.7 Introducing a Point Source Based on Knowledge About the Emission Process we will discuss the second alternative to be used for emission variations where we have information about the emission process. To create a formula: Click on the Formulas under Subtables in the EDB menu, then the Formula subwindow will appear. Click on Add (or click on STANDARD if you want to edit the default formula) Working with the Emission Database (EDB) Swedish Meteorological and Hydrological Institute, SE-601 76 Norrköping, Sweden Page19(62) Phone: +46-11-495 8000, Fax: +46-11 495 8001 Type in a formula name in the Name information text field Define the yearly variation on Configuration by clicking on Day type, Temp & Gas Velocity or Scenario & Month Figure 3.3.3.1. The Point subwindow The Formula / Scenario & Month subwindow will appear showing 10 text fields marked with yearly figures. In these text fields you can describe the absolute variation of emission in percentage over the years. Figure 3.3.3.2. Scenario and Month Normally you should type 100 for the present year, meaning a factor equal to 1. If you estimate that the yearly emissions will double by the year 2000, then type 200 in that text field. Airviro version v3.20 Page 20(62) April 2010 Note: The scenario names are texts that can be changed by the user, these can be modified and saved under Basic Setting (EDB menu). Confirm the table (OK) and leave the subwindow. Define the monthly variation by clicking on Scenario & Month The Scenario & Month sub window will appear containing 10 Scenario variations, and 12 Monthly variation text fields labelled for each month of the year. In these text fields you can describe the relative variation of emission during the year. The figures entered here will be normalized at the moment EDB uses them to estimate emissions. This will be explained mathematically in Appendix 1B, and you will see the effects and understand the principles later on when you perform dispersion calculation (simulations). Example1: If you write 100 for all months but put June and July = 0 then no pollutants will be emitted during these summer months, but the total yearly emission will be evenly distributed over the other ten months. If you had written 200 instead of 100 for all months except June and July the result would have been the same. Example2: If you write 75 for 6 months (October-March) and 25 for the other 6 months (April-September), then emission will be three times higher in the winter than in the summer. You will get the same result if you had given the figures 300 and 100 instead of 75 and 25. Figure 3.3.3.3. Temperature and Gas Velocity variations When you are ready, click on OK and leave the subwindow. Note: These figures are not normalised if linked to a source defined in terms of a fuel. Now define the emission dependency on outdoor temperature by clicking on Temperature & Gas velocity The Temperature & Gas velocity subwindow will appear and a column with 30 text fields marked with the outdoor temperature intervals is displayed. See Figure 3.3.3.4. In these text fields you can describe the relative variation of emission as a function of the outdoor temperature. This is explained mathematically in Appendix 1B: Mathematical Definitions of the Formulae Used in the EDB. In 3.3.5 Specifying a Point Source Based on Yearly Total Working with the Emission Database (EDB) Swedish Meteorological and Hydrological Institute, SE-601 76 Norrköping, Sweden Page21(62) Phone: +46-11-495 8000, Fax: +46-11 495 8001 Emission Figures and 3.3.7 Introducing a Point Source Based on Knowledge About the Emission Process examples will be given showing how to use this table. Click on OK to save the temperature information Define the exhaust gas velocity by clicking on Temperature & Gas velocity... The Gas velocity subwindow will appear and a column with 20 text fields is displayed. In these text fields you can describe the relative variation of exhaust gas velocity as a function of the production rate. See Figure 3.3.3.3.Maximum gas velocity has to be given as static information when you define the point source (see 3.3.4 Static Emission Information and 3.3.6 Emission Simulation from a Point Source). The information on exhaust gas velocity is important in order to compute the so-called plume lift. In large power plants the exhaust velocity from the stacks can vary substantially depending on the production rate. This is further explained in 3.3.7 Introducing a Point Source Based on Knowledge About the Emission Process. Click on OK to save the gas velocity information Exercise 3.3.3.1 Create a formula named industry_2shift where there is a constant emission during working days between 6 a.m. and 10 p.m., and no emission at all during other times of the day (or during weekends). The industry is completely closed in July. Figure 3.3.3.4. Day type variation Define the daily and hourly variation by clicking on Day type...The Day type subwindow will appear and 4 columns with 24 text fields marked with the day types: Monday-Thursday, Friday, Saturday and Sunday are displayed. There are 24 text fields in each column defining the hours during the days. In these text fields you can describe the relative variation of emissions during the week. The figures you enter will be normalised at the same moment EDB uses them to estimate the emissions. This is explained mathematically in Appendix 1B, and you can see the effects and understand the principles later on when you perform simulations. Example3: If you write 100 for all hours during Monday-Thursday and Friday but 0 over the weekend then no pollutants will be emitted during Saturday and Sunday but 7/5 of the weekly average emissions will be emitted during workdays. When you are ready, click on OK and leave the subwindow. Airviro version v3.20 Page 22(62) April 2010 3.3.4 Static Emission Information There are important emission characteristics that do not affect the emission strength, but must be known in order to utilise the emission information in a dispersion model so that the effect of emissions in the ambient air can be determined. The static information is defined as: Chimney height. It is important to know the release height when we apply a dispersion model. Generally speaking: the higher the stack is, the lower pollutant concentration on the ground close to the stack. Inner diameter of chimney and Exhaust gas velocity are used to compute the vertical displacement of the pollutants before the horizontal wind and turbulence transports the pollutants and mixes them down to lower levels. We use these figures to compute the so-called effective stack height. It is also important to know the Exhaust gas temperature when we want to determine the effective stack height. If the gas is considerably warmer than the surrounding air, then the buoyancy effect will create a large plume lift. Figure 3.3.4.1. Effective stack height The Outer diameter of the stack as well as large buildings in the vicinity affect the wind flow close to the stack and consequently the dispersion pattern. In some cases a considerable down draught can occur creating high concentrations of pollutants on the ground close to the source. Working with the Emission Database (EDB) Swedish Meteorological and Hydrological Institute, SE-601 76 Norrköping, Sweden Page23(62) Phone: +46-11-495 8000, Fax: +46-11 495 8001 Figure 3.3.4.2. Buildings Buildings can create an effect if the stack is less than 2.5 times as high as the buildings. You should give the dimensions of the largest nearby building, as this will have the greatest influence. Note: The static information is not necessary in order to simulate emissions in the EDB but it is vital if you want to simulate the air quality effects using the dispersion models in the Dispersion module. Therefore we recommend that you always document the static information as soon as you add a point source to the EDB. 3.3.5 Specifying a Point Source Based on Yearly Total Emission Figures You are now ready to introduce the first point source in the EDB. The first example is based on a typical situation from real life. You have asked Mr. John Smith, the environmental manager of a medium size company (a cement factory) about the emissions of NOx. He has given you the total emission during the year and indicated the periods during which the factory is closed. Additional information about stack height, exhaust temperature, etc. has been given and the information can be summarised as follows: Company name: Cement and Son Ltd. Total yearly emission of NOx: 600 tons Stack height: 45 m, outer diameter: 2 m, inner diameter: 1 m. Stack mounted on a building of dimension 50*40 m1 and height 32 m. Exhaust gas temperature: 12 C, velocity: 8 m/s Production on working days (Monday-Friday) between 6 a.m. and 10 p.m. Closed in July. 1. The house width should be calculated as widthlength Mr. John Smith estimates that the production will increase by about 10% per year until the year 2000. Please remove this. Note: Remember, you can describe sources with other characteristics for each Domain. These are activities and geographic codes, other characteristics entered by the user are Alob and collect ER. Airviro version v3.20 Page 24(62) April 2010 How to Specify your First Point Source in the EDB Click on Source in the EDB main window and then click Select on the map. A hair cross will appear when you move the mouse pointer over the map area and the computer waits for you to select an area. Press the right mouse button to enter the Point subwindow without having to select a subarea. Figure 3.3.5.1. Point source Note that it is only necessary to select a subarea if you want to edit an existing point source or if you want to copy information from an existing source to a new source. To select an area, hold down the left mouse button and drag it over the area you want to choose, then release it. The Points subwindow appears, and in the list box to the left all existing sources in the selected area are shown. In this case, working with the personal EDB: My_first_EDB, there should not be any existing sources. Click on Add and the hair cross appears in the map area. Select the desired location of the source by positioning the hair cross and clicking on the left mouse button. The Point subwindow appears again and then click on Edit mode for you can start to fill in information. Start to fill in the name of the company in the upper text field Name Continue to fill in the Additional Information and If you want to change the location of the source on X Coord and Y Coord Select the proper Formula by clicking on industry_2shift Fill in the emission figure by dragging the option menu button down to Emission. The substance emission subwindow appears. Select NOx from the list box and fill in the total yearly emission (tons/year) in the relevant text field. Confirm by clicking on OK. Working with the Emission Database (EDB) Swedish Meteorological and Hydrological Institute, SE-601 76 Norrköping, Sweden Page25(62) Phone: +46-11-495 8000, Fax: +46-11 495 8001 All information except Search keys and the Info and Info2 string (we will introduce them later on in 3.3.8 Using Search Keys and Pattern Matching Facilities as Search Conditions) has been given, Select the available Codes and Alob. Codes are used to categorize sources in EDB. These can be geographic codes or activity codes. These codes are defined selecting the Basic Setting menu The Alob can contain any amount of text. It is used to store data that is impossible to store in the other fields of the point source. If the text in an Alob is in tag = value format, these can be used as search criteria. Example: NO_CARS=12 FUEL_CONSUMPTION=1000 Figure 3.3.5.2. Codes Figure 3.3.5.3. Alob PI: Remove this. Select the CollectER available. CollectER is available only for defining point sources. PI: Remove this. Estimating emissions at the level of countries, states, regions or provinces and even larger companies in most cases is a knowledge-intensive exercise. Guidelines, guidebooks and other guidance documents to prepare emissions inventories typically contain thousands of pages with emission estimation methods and specific and aggregated Airviro version v3.20 Page 26(62) April 2010 emission factors for large numbers of sources. The European Environment Agency’s compile the emission inventories with the ColR. The EIC Module is designed for storing and managing emission inventory data from CollectER. Figure 3.3.5.4. CollectER Fill in the Aermod menu, with the emission characteristics. They will be used in the Dispersion Module (Aermod Model). Width, height, length, centre, and distance to the farthest wall, must be entered for each building. All values must be in meters. At least one segment must be defined for each point source. Figure 3.3.5.5. Air Model Finally, save the information by clicking on Apply. 3.3.6 Emission calculation from a Point Source We can use a point source to perform an emission calculation. Emission calculations are performed using the Search criteria subwindow. The search is carried out over the map area that you see on the screen, so that if you have zoomed into a subarea then only that subarea will be searched. Working with the Emission Database (EDB) Swedish Meteorological and Hydrological Institute, SE-601 76 Norrköping, Sweden Page27(62) Phone: +46-11-495 8000, Fax: +46-11 495 8001 Click on Search Criteria in the EDB main window. The Search criteria subwindow will appear on the screen. See Figure 3.3.6.1. Figure 3.3.6.1. Search criteria The Search Criteria subwindow: Name Information: The three text fields Name, Info and Info2 gives you the possibility to write the characters you want to match when searching for sources in the Edb. If you write Cement and Son Ltd. in the Name text field then the sources with exactly that name will be found, and no other sources. There is the possibility to use so-called ”wild cards” in connection with the strings. For example: If you write Cem* then all sources with a name starting with Cem will be selected. For further information see 3.3.8 Using Search Keys and Pattern Matching Facilities as Search Conditions. Substance: You must select a substance from the substance list. Sources: You can select any combination of point, area and road sources. For example, if you enable the Point and Area toggle buttons then only point and area sources will be included in the search. Correction: this consists of three choices: Correction gives you the possibility to multiply the emission from point, area and road sources with an arbitrary factor. Variation: Scenario allows you to change to a different scenario. If you select Time & temp the Time and Temp subwindow will appear. You can give selection constraints concerning time such as: Month, Day type, Hour and Temperature. This gives you the possibility to compare emissions such as the emissions during rush hour on Mondays in September with daily emissions on Saturdays in June. The Temperature gives you the possibility to prescribe the outdoor temperature or the frequencies of outdoor temperature. Instead you can activate the Dependent on time option, in which case a temperature distribution based on the time restrictions that you have made will be automatically included. From / To is used when calculating the emission from a certain time period. If the EDB contains sources that uses time series to define the emission, this is the only way to calculate the emission from these sources. Airviro version v3.20 Page 28(62) April 2010 PI. Remove this. NOTE: Since version higher than 3.13 you have also the possibility to filter the information using the radio button FROM: /TO: to select the information that match this filter criteria. Restrictions consist of four subwindows. 1. Point, Area & Grid restrictions give you the possibility to select point/area/grid sources that are defined with a specific Substance group, Fuel and/or Formula. Defined restrictions are applied simultaneously (using Boolean AND criteria). A maximum of 10 selections can be made in each list. 2. Road restrictions give you the possibility to select line sources (traffic roads) that are based on a specific Road type, Vehicle type and typical Speed on the road (see 3.6 Traffic Emissions in the EDB). A maximum of 10 selections can be made in each list. Restrictions can be define according to the number of vehicles per day (minimum and maximum) and road length (minimum and maximum). 3. Search key restrictions give you the possibility to estimate emissions from sources that have been given specific search key (see 3.3.8 Using Search Keys and Pattern Matching Facilities as Search Conditions). An unlimited combination of search keys can be made. 4. Sub area restrictions allow you to define a geographical area in which to perform the search for emission sources. 5. Codes and Alob restrictions gives you the possibility to filter information according to the codes that were previously defined. 6. Apply, save all settings. Output Setting emission rates are usually expressed as grams per second (g/s) or the other units. There are four different output functions: 1. Normal output means that all sources that fulfil the search criteria will be displayed on the map (on the screen), both location and emission strength. You can use the option Show emission sources with nr of decimals. A maximum of 8 decimals can be select in each list. 2. Grid output means that you can define a grid with a user-defined resolution over the map or a subarea within the map. The total emission in each grid cell will be displayed using graded colours. You define the grid resolution, colours, etc. 3. Report is the EDB Report Generator, only Txt format. Here you can define several types of reports to display information from the EDB. The Report Generator is described in 3.8 Creating EDB Reports and displaying the Database structures. Working with the Emission Database (EDB) Swedish Meteorological and Hydrological Institute, SE-601 76 Norrköping, Sweden Page29(62) Phone: +46-11-495 8000, Fax: +46-11 495 8001 4. Noise output means that all road noise emission levels will be displayed with different colours on the map. This is standardized with colour-coded range. Example. Make the following selection in the Search Criteria subwindow: Search strings: Name: Cem* Substance: NOx Sources: Point Restrictions: - Variation: Time & temp: Scenario: 1993 Month: all Day type: all Hours: all Temperature: not used Variation: Corr. Factors Point: 1 Area: 1 Road: 1 Click on Output (Gif or PDF) .The position of the source Cement and Son Ltd. will be displayed and the emission estimation is 19 g/s. That is exactly what will be emitted as an average during the period you have selected. If you instead ask for the figure expressed as tons/year, you will be given the answer 600 tons, i.e. the yearly emission figure that you gave when the source was defined. Click on Search Criteria and change the time constraint to: Variation:Time & temp: Scenario:1993 Month:all but July Day type: Mon-Fri Hours:6-22 Temperature: not used i.e. the production period at the factory. Click on Output (Gif or PDF) and then the estimated emissions will be 43.6g/s. This is the mean emission rate coming from the stack during production time. The yearly emission equivalent would represent what the total emission would be during a year if the factory were running all hours and days during the year with that emission rate. Exercise 3.3.6.1 Simulate the mean emission for Fridays during the period May-September. The answer should be 23.3 g/s. Simulate the yearly mean emission at the year 2000 (Hint: use the correction factors). The answer should be 20.9 g/s, which is 660 tons per year - exactly a 10% increase on the present mean emission. Note: When converting between g/s and tons/year it is assumed that there are 365.25 days in a year. Airviro version v3.20 Page 30(62) April 2010 3.3.7 Introducing a Point Source Based on Knowledge About the Emission Process In many cases you will not gain information about the total emission during a year, but information about the process that causes the emission. To incorporate all the information we know about such a source we have to work through the following steps: 1. Create a formula describing the time and temperature variation of the source 2. Create a fuel type specifying the energy value and the emission either as grams per mega joule or as a percentage of the fuel weight. 3. Create a point source linked to the formula and fuel type and specifying the maximum effect of the process. The following example shows typical information given from a fossil-fuelled power station used for district heating. Heat production for hot water consumption at night time (10 p.m. – 6 a.m.): 10 MW Heat production for hot water consumption at day time (6 a.m. – 10 p.m.): 20 MW Heat consumption as a function of the outdoor temperature: Outdoor temperature 20 15 10 5 0 -5 -10 Heat consumption 0 MW 20 MW 40 MW 60 MW 80 MW 100 MW 120 MW Maximum effect of the boiler: 100 MW Type of fuel: Oil (43 MJ/kg) SO2 content: 0.2% NOx production in the process: 0.1 g/MJ Stack height: 85 m, outer diameter: 2 m, inner diameter: 1 m. Stack mounted on a building of dimensions 50*40 m and height 32 m. Exhaust gas temperature: 120 C, velocity: 15 m/s Working with the Emission Database (EDB) Swedish Meteorological and Hydrological Institute, SE-601 76 Norrköping, Sweden Page31(62) Phone: +46-11-495 8000, Fax: +46-11 495 8001 If we analyse this information we find that the heat consumption including the hot water will exceed the capacity of the boiler at lower temperatures than 0 during daytime and roughly –2 in the nighttime. Obviously the energy company must supply energy from an additional production unit when the consumption exceeds the maximum capacity of the boiler above. If we had been given information about the additional capacity of production (and emission), we would have been able to include this information. However, in this case we are explicitly interested in describing the emission from one specific boiler as we want to focus on the possibility of simulating the emissions in a realistic way, i.e. so that differences between day and night time, temperature dependency and maximum emission are properly described. In order to introduce the information in the EDB we start to define a Formula named oil_boiler in the same way as in Exercise 3.3.3.1. The relative figures in the monthly, daily, and temperature tables have to be defined as relative to the maximum production rate. Consequently, in the Day type table you should write 10 (%) during nights and 20 (%) during daytime for all day types. In the Temperature table, you should convert the heat consumption figures to percentage figures (actual heat consumption/maximum heat production). No specific information has been given regarding monthly or yearly variation. Consequently, we write 100% in the Month and Scenario tables. After you have saved the formula you have to define a Fuel. Within this database you can define the emission as a function of a burning process and a fuel involved in that process. Click on Subtables and then on Fuel…. The Fuel subwindow will appear. Figure 3.3.7.1 Fuel Click on Add and type the name oil_example1 in the Name text field and the Energy value in the next text field Emission (g/MJ): click on Substances… and fill in the NOx value 0.1 g/MJ Emission (%): click on Substances… and fill in the SO2 value 0.2% Save the settings and leave the subwindow (Apply) Airviro version v3.20 Page 32(62) April 2010 The next step is to define the source: Click on Source. The Point subwindow will appear. Click on Add and select a position on the map. Then, type in the Name of the source (oil boiler) and complete the Additional info… based on the information above. Select the Formula oil_boiler. Click on the Emission option menu and choose Fuel. The Fuel emission subwindow will appear. Select a fuel: oil_example1 and type the maximum production effect (100 MW) in the text field. Click on OK. Save the point source information, click on Apply. The emission from this source can now be calculated in the following way: 1. For NOx (which is emitted in g/MJ) the emission formula is Total Emission [g/s] = fa x MaxEffect [MJ/s] x 1000 x RelativeEmission [g/MJ] 2. For SO2 (which is emitted in % weight) the emission formula is [%]Re1000]/[]/[]/[ sionlativeEmiskgMJeEnergyValusMJMaxEffectfsgionTotalEmiss b where fa and fb are factors created from the scenario, month, day type, temperature and gas velocity tables. The factor of 1000 in the second equation is to convert the result from kg/s to g/s. To verify the emission figures we go back to the Search Criteria subwindow and set the following values: Search strings: Name: oil* Substance: Nox Sources: Point Restrictions: - Variation: Time & temp: Scenario: 1993 Month: all Day type: all Hours: all Temperature: Yearly mean Variation: Corr. Factors Point: 1 Area: 1 Road: 1 Output: Normal No. of decimals: 1 For NOx the mean annual emission is 216.8 tons/year. For SO2 the mean annual emission is 100.8 tons/year. Working with the Emission Database (EDB) Swedish Meteorological and Hydrological Institute, SE-601 76 Norrköping, Sweden Page33(62) Phone: +46-11-495 8000, Fax: +46-11 495 8001 Exercise 3.3.7.1 Manually change the temperature settings, specify the hour of the day, and simulate the emissions for the following cases (you can search for a certain temperature interval by specifying 100% for that interval and 0% for all other values): Outdoor Temperature 20 15 11 5 1 -1 -3 -5 -10 Emission NOx at 12 o’clock 1.02 1.86 Emission SO2 at 12 o’clock Fill in the table. 3.3.8 Using Search Keys and Pattern Matching Facilities as Search Conditions The Search Keys All emission sources in the EDB can be classified using five groups of search keys. In the first two groups there are 128 individual search keys and in the last three there are 32 in each group. The benefits of the search keys are obvious by looking at some examples: Assume that you have a large number of districts (municipalities) in your territory. Utilize the first group of search keys by defining all districts by name in the first search key list. In the second search key list you may group different activities that contribute to pollution, such as Petrochemical industry, Automotive industry, Traffic, Lawn mowers, etc. In the third search key list you can categorize your emitters into classes such as: Private industry, State owned industry, Public sector, Private consumption, etc. In the forth you may categorise the area in which the emitter is located, such as: rural, sub-urban, residential, inner city, etc. Later on when you want to estimate the total emission from lawn mowers in a certain district in the residential areas you can have your answers very quickly. If, before filling the emission database with figures and formulas, you analyse your future needs concerning emission estimation, you will find that the search keys can play an important role, giving you a convenient emission database handler. You will benefit from constructing and utilising good search key lists. They provide a very efficient way of searching in the database for certain groups of pollution sources. You can search using unlimited combinations of search keys from the different searchkey lists. The Search Strings The Search strings (Name, Info1 and Info2) that can be given for all sources can be extremely valuable as a complement to search keys. The first string (Name) consists of 47 characters. It is Airviro version v3.20 Page 34(62) April 2010 the intention that you should include the name of the source in this string (such as Oxford street or Shell, etc.). In addition you are free to fill the whole string with characters and numbers that can be valuable to classify the source in a convenient way. As an example you can provide a national identification code, property code, etc. If you provide unique characters as separator between the information, it will be easy (as demonstrated in next paragraph) to use matching facilities when searching for emissions in subsets of the database. The two extra strings Info and Info2 consists of 47 characters and can be used in the same way as Name to imput information related to the emmision source.. Matching Search Keys When simulating emissions using the Search Criteria subwindow you can restrict your search in the database by clicking on Searchkeys. In this subwindow you can select more than one search key for each one of the five groups. If you have chosen more than one search key in a group, all sources belonging to any key in the selected subset will be extracted from the database (or-criteria). If you have chosen combinations in two search key groups, then sources belonging to any key in the selected subset in the first group and any key in the selected subset in the second group will be extracted from the database. Between groups we have an and-criteria. For example: Suppose you have selected district1, district2 and district3 in the first search key group, and Lawn mowers and traffic in the second, but no selection in the next three groups. The following sources will then be extracted from the database: Sources with 5 search key definitions such as: a) District1, Lawnmowers, Private consumption, Resident, Green b) District2, Lawn mowers, -, -, - c) District3, Traffic, -, -, Yellow The following sources will not be extracted from the database: d) District1, Petrochemical industry, Private industry, Sub-urban, Black e) -, -, -, -, Brown f) District3, -, -, -, - The - indicates that no search key definition has been made. Matching Search Strings In the Search Criteria subwindow, you are free to select a specific source by defining the Search strings so they match a specific source. But if you want to match all the sources that have some characters or numbers in common in the search string definition you can apply the following pattern matching possibilities: Working with the Emission Database (EDB) Swedish Meteorological and Hydrological Institute, SE-601 76 Norrköping, Sweden Page35(62) Phone: +46-11-495 8000, Fax: +46-11 495 8001 A* All strings beginning with an A (capital letter) *street All strings ending with street *street* All strings that contain the word street *street*|*avenue* All strings containing the word street or avenue ?A* All strings in which the second letter is an A [Aa]* All strings that begin with an A or an a [A-F]* All strings that begin with capital letters between A and F ^K* All strings that do not begin with an K *[^h-k] All strings that do not end with small letters between h and k Examining the matching capabilities, you will realise that a carefully prepared strategy concerning search string definitions will allow the user to have unlimited possibilities of selection criteria. Note: When filling in the name and information strings for a source, you should not use the reserved characters |, *, ^, $, ., [, ], {, }, ?. 3.3.9 Saving your search criteria and output settings When you have defined all search criteria, you may save the query as an EDB macro. The EDB macro saves all settings in the user interface, so they can be used at a later stage. When Load Macro menu is selected, a new window appears that allows the user to load a macro previously defined and saved in any of the groups created. Individual groups can be created for each user using the same name, or a common group for all users. Save Macro, allows you to save macros, and Delete Macro, allows you to remove existing macros. This concept is the same for output settings. The macro saves all defined restrictions on Search criteria and Output settings. It is recommended that you save your Macro with a meaningful filename so that you can easily recognize the content. Airviro version v3.20 April 2010 Page 36(62) 3.4 Area Sources in the EDB 3.4.1 What is an Area Source? An area source is a pollutant source that is widely spread over an area. The leakage from pipes, valves and tanks at a refinery is a typical example of an area source. Usually we don’t know exactly the locations of emission, so we treat the whole area as a source and assume that the emission is evenly distributed. The static information that is used for point sources is not included in the area sources. In the representation of the area source, the map is divided up into grid squares, and the emission in each square is calculated. This reduces simulation time so that it can happen that an area source simulation runs quicker than a point source simulation, if there are many small point sources. In a simulation, the area source emission will take place 2 m above the ground and there is no emission velocity. 3.4.2 General Principles In the EDB you can define an area source as a rectangle. To include an area source in the EDB is very similar to the inclusion of a point source, but instead of clicking on a point you must define an area by dragging the mouse on the map. Emissions can be defined using an Indico macro. The macro must be previously defined using Indico Presentation. The general principles are the same as for point sources. You can save the search and output settings. You can use Formulae, Fuel, etc. in the same way you do for point sources. PI: Remove this. except for Aermod and CollectER options. Grid Layers in the EDB Working with the Emission Database (EDB) Swedish Meteorological and Hydrological Institute, SE-601 76 Norrköping, Sweden Page37(62) Phone: +46-11-495 8000, Fax: +46-11 495 8001 3.5 Grid Layers in the EDB 3.5.1 What is a Grid Layer? A grid layer in the EDB is a collection area sources spread over a large area. These sources are grouped into a grid layer. A typical example is household heating: is it often possible to estimate the amount of fuel that is consumed in each area of a city. From this information is it possible to create a grid of emission sources. For each grid layer the information that is common for all grid cells is stored only once. Only the information that might be different is stored for each grid cell. The emission from each grid cell is always stored. It is of course possible to store the emission sources in the grid as area sources instead but the grid layer solution has some advantages compared to the area sources: Increased computation speed. Disc space requirements will decrease, often quite dramatically. The import format for grid sources is simpler than the format for area sources. 3.5.2 General Principles A grid layer can only be created with the grid ASCII interface, a shape file or Wedbed. The geographical information about the grid, the data that is specific for each grid cell and the common information is used as input at creation time. The menus for the grid layers are exactly the same as for area sources but only the common information of the grid layer can be modified. Another difference is that the emission from a grid layer must be specified as substances or substance groups. The grid can use only the option Codes. Click on Grid in the menu bar , and when pressing the Grid Source option, the following window appear, and allow input the grid source (Figure 3.5.2.1. Grid Sources).When pressing the Grid Import option, the following window appear, and allow import the grid source (Figure 3.5.2.2. Grid Import). Airviro version v3.20 April 2010 Page 38(62) Figure 3.5.2.1. Grid Sources Figure 3.5.2.2 Grid Import Working with the Emission Database (EDB) Swedish Meteorological and Hydrological Institute, SE-601 76 Norrköping, Sweden Page39(62) Phone: +46-11-495 8000, Fax: +46-11 495 8001 3.6 Traffic Emissions in the EDB 3.6.1 What is a Road source? A road source is a mathematical idealisation that does not exist in reality. When we talk about road sources we generally mean emission from road traffic. Every car moving on the road is more or less a point source, although we can never locate or follow any individual car. For the EDB user it is quite convenient to define the road traffic (or may be shipping route traffic, etc.) by drawing a line on the map. In urban areas, the dominant part of the air pollution can be derived from road traffic emissions. Consequently, the quality of the work concerning traffic emission data is the most crucial part in the construction of an EDB. However, the number of roads and cars in a large city are so numerous that we need to simplify the handling of the data. Below you will find a description of the principles of the Airviro traffic emission data processing. The method described can be refined but is still very efficient in terms of manpower needed to set up a traffic emission database for a large urban region. 3.6.2 General Principles You can, in an interactive way, define the positions of a road graphically on the map/screen. When the position of the road is fixed, you have to give information on traffic speed, traffic intensity and variation as well as information on the types and proportions of vehicles operating on that road. However, the traffic behaviour is likely to be similar on several roads. Consequently, the traffic variation as well as proportions of different vehicles on a road can be defined in groups of Road types. The typical number of Road types that you will have to define is likely to be 10-25 depending on the complexity of the area. Instead of defining all traffic variation characteristics on each road, you simplify the work by addressing the information to be found in the Road type database. The emission factors from different vehicles are found in the Vehicle database. The emission factors in the Vehicle database are referred in the Road type definitions in the Road type database. To be able to simulate traffic emissions it is likely that you have to define 5-25 different emission tables in the Vehicle database. The typical amount of traffic information that you have to supply in order to describe the traffic emissions in a large city is: Roads: 500-1000 roads or road links Airviro version v3.20 Page 40(62) April 2010 Road types: 10-25 different road types Vehicles: 5-25 tables with emission factors from different vehicles. Vehicle Road Name and Info Road location Daily mean number of vehicles Number of lanes Speed Congestion data (limit, vehicle and speed) Road type Search Keys Codes Height Alob Road Type Road type name Type of vehicles on the road Yearly variation of traffic intensity Monthly variation Day type and daily variation Speed restrictions Vehicle Vehicle name Substances emitted Emission as function of speed Working with the Emission Database (EDB) Swedish Meteorological and Hydrological Institute, SE-601 76 Norrköping, Sweden Page41(62) Phone: +46-11-495 8000, Fax: +46-11 495 8001 3.6.3 Introducing Emission Factors for Vehicles Emission from vehicles is mainly dependant on: The type of vehicle, classified depending on the engine type, fuel used, weight class, ambient temperature and pavement types. The driving behaviour and the general traffic environment. The speed the vehicle is travelling at. In many countries, emission factors have been derived based on the factors above. You are able to include these in the EDB. Sets of emission factors are included in the Vehicle database in the Airviro Reference database. The emission factors are basically derived as functions of: Substance NOx, CO and total HC Speed 0-120 km/hour Type of vehicle Light vehicles and Heavy vehicles (>3.5 ton) To include the driving pattern, separate emission factors are given in various traffic situations. Consequently, vehicles that are driving in the centre of a city tend to accelerate and slow down more than vehicles on a highway. The name: Lv cat tho 50 10s represents the emission factors for light vehicles (lv) equipped with catalytic converters (cat), driving on a through-road (tho), signed maximum speed: 50 km/hour (50), and the vehicles have to make 10 stops or turns/km (10s). The way in which it has been chosen to structure the road types and vehicle types is based on a Swedish model, the VETO model, and this model is used here as a typical example. Other models exist that are not quite the same but you should be able to adapt the EDB to these other traffic models when you define road types and vehicle types. You may also want to refine your traffic EDB by introducing other important processes, e.g. defining vehicles with higher emission due to low temperatures in the combustion process (cold start), etc. If you click on Subtables and then on Vehicle... in the EDB main window the Vehicle subwindow will appear. In the left list box you can see all the different emission factors that are given in the Reference database. If you would like to define a new vehicle type and the corresponding emission factors, you simply click on Add in the lower left corner. To edit an existing vehicle, click on the proper vehicle in the left list box. If it is a new vehicle, you have to name it by typing it in the upper right text field. You can define or add a substance by clicking in the list box named Substances. To edit or add the emission factors as a function of the vehicle speed. You can see the substances, which are defined to be emitted from the vehicle type. The Speed table to the right, is disabled until you have clicked on a specific substance. As soon as you have chosen a substance the Speed table will be enabled and you can add or edit the emission factors as a function of the vehicle speed. Airviro version v3.20 Page 42(62) April 2010 Figure 3.6.3.1 Vehicles In the example shown the vehicle Hv 1990 tho 50 1s and substance nitrogen oxides (NOx) have been chosen. A table of emissions as a function of speed will appear as illustrated in the figure. You can edit the table and save your modified emissions by clicking on Apply. 3.6.4 Naming Standard for Emission Factors There are several reasons why you should name your different emission factors in a structured way. As soon as you start to work with the Road types, you will recognise an obvious reason to have a corresponding name convention in order to link different emission factors to the corresponding Road types. In the model used in the Airviro Reference database, the name of the emission factors is defined by the characteristics: vehicle type and traffic environment, i.e. the emission factors are constructed in the following way: Example Type of Vehicle Vehicle subset Type of Road Signed maximum speed Number of stops/turns per km Lv cat hig Light vehicle Catalytic converter Highway 90 0 Hv 1990 tho 70 1s Heavy vehicle Old type Through road 70 1 Lv tho 50 10s Light vehicle No catalytic converter Through road (city street) 50 10 Working with the Emission Database (EDB) Swedish Meteorological and Hydrological Institute, SE-601 76 Norrköping, Sweden Page43(62) Phone: +46-11-495 8000, Fax: +46-11 495 8001 3.6.5 Introducing Road Types To be able to simulate the emissions at a specific hour caused by the traffic, we need to know the typical traffic variation on the streets and roads. However, from a practical point of view, it is not possible to define the traffic time variation separately for every road and street in an urban region. In the EDB it is assumed that typical traffic behaviour can be categorised in classes. These classes are called Road types and consist of: Proportions of different vehicle types on the road Yearly index (expected increase or decrease of traffic in the future) Monthly variation Daily variation (within 4 different day types) Hourly variation Speed restrictions In order to define a road type, click on Subtables and then click on Road type... in the main window. The Road type subwindow will appear; now, in order to edit an existing road type select one in the list box to the left. To create a new Road type, click on the Add button, at the bottom of the list and enter a name for the new road type in the Name text field. The next step is to define the type of vehicles that operates on this road type. Select the proper vehicles in the Vehicles list box on the right side. To define the rates of vehicles you have to click on Scenario.... Figure 3.6.5.1 Roads Type The Scenario subwindow appears and you are able to fill in the percentage of the different vehicle types. You can define the expected rates for up to 10 different years or scenarios. This table is basically the same as the Scenario table in the Formula database, i.e. the figures will be treated as absolute values (as percentage) and will later on be multiplied by Airviro version v3.20 Page 44(62) April 2010 a daily total number of vehicles on a street. The scenario figures in the Road type definition can be used to forecast future changes in the traffic intensity, vehicle rates and accordingly the future emissions caused by traffic. Save your figures and leave the subwindow by clicking on OK. Note: if the percentage for a specific scenario sums up to 100, the daily total number of vehicles will multiply the number 1.00. If the sum had been 120 for a different scenario, then the daily total number of cars on a specific street will multiply the factor 1.20. As for the yearly variation, you can define monthly variations by clicking on Month.... Note that this table is similar to the Month table in the Formula database, i.e. all figures are relative and will be normalized when used. Save your monthly figures and leave the subwindow by clicking on OK. You can define hourly traffic variation by clicking on Day type... . The Day type subwindow will appear, and the principles here are similar to the Day type table in the Formula database. By clicking on one of the existing vehicles on the Vehicles list box on the left, you can fill in the hourly traffic variations in the text area. Please note that the figures are relative, i.e. they will be normalised as described in 3.3.3 Dynamic Emission: Formulae for Time Variation and Temperature Effects. Save your daily figures and leave the subwindow by clicking on OK. Figure 3.6.5.2 Speed restrictions Finally, you can define speed restrictions for the different types of vehicles operating on the Road type. Click on Speed rest... and the Speed restriction subwindow will appear. Click on the desired vehicle in the left list box (Vehicles). Now you can prescribe a minimum and a maximum speed for that type of vehicle. This feature is very useful if you want to define speed differences between heavy and light vehicles. Save your speed restrictions and leave the subwindow by clicking on OK. 3.6.6 Introducing Traffic Information in the EDB After you have created emission factors for different types of vehicles as well as a number of typical road types you are ready to introduce road emissions into the EDB. In the main window, select Road... . Click on Select on map, a hair cross will appear in the map area and the computer waits for you to select an area. To select an area, hold down the left mouse button and drag it over the area that you want to choose, then release it. The subwindow Road appears and in the list box to the left all existing roads within the chosen area are displayed. If you click on any of the existing roads the location of it will be displayed on the map. To introduce a new road, click on Add in the lower left corner. The Working with the Emission Database (EDB) Swedish Meteorological and Hydrological Institute, SE-601 76 Norrköping, Sweden Page45(62) Phone: +46-11-495 8000, Fax: +46-11 495 8001 subwindow disappears and a hair cross appears on the map. Position the hair cross on the map at the start of your new road. Click on the left mouse button. Move the hair cross to the next position of your road. A rubber band will be stretched between the last position and the hair cross. Find your new position and click on the left mouse button. Continue in this way until you have defined the whole road extension. Then click the middle mouse button (escape) or right mouse button to return to the subwindow. Figure 3.6.6.1 Roads Now you have to fill in the characteristics of the road. Start with the road name in the Name text field, and a code definition in the Info text field. The next step is to fill in the traffic information. Fill in the total number of Vehicles per day (this should be the yearly mean traffic for a day). Also enter Number of lanes (in total), although this field is currently not used. You may also give a Correction factor, by which the Vehicles per day is always multiplied. This should be 1 if you do not want any correction effects. Select the typical speed for the road. Remember that the speed is an emission factor. Also define characteristics for traffic congestion, like congestion limit, congestion speed and congestion vehicle. Airviro version v3.20 Page 46(62) April 2010 It is possible to characterize the road traffic by defining the free flow and the congestion. These parameters change the emission factors. The congestion is the major demand of vehicles that the road can support. It is defined by the number of vehicles that travel per day on the road. Select a proper road type from the Road type list box in the lower right corner. Then select suitable search keys. Select a geographic or activity code from Codes. It is the same concept used for point sources. Remember these codes are defined on Basic Settings. You can input complementary information about surrounding buildings (slope, distance to house, house width and house height). For this you must use the button Height. And then, you select a characteristic from button Alob. It is the same concept used for point sources. Remember these codes are defined on Basic Settings. Finally, you can enter the noise factor with the following parameters: vehicle speeds, proportion of heavy goods vehicles, gradient and type of the surface (e.g. bitumen, concrete and porous asphalt). Remember, that for characterizing a source with noise factor, this must be previously enabled. Save your road definition by clicking on Apply. 3.6.7 Emission Simulation with Road Sources and Restrictions Simulation of emissions based on road sources are identical to point sources as described in 3.3.6 Emission Simulation from a Point Source. However, there are certain features unique for the road emission as can be seen in the Search Criteria subwindow below. If you want to simulate road emissions exclusively, you have to put the toggle button Road on and both Point and Area off. Clicking on Road... can see restrictions that are specific for road emissions. Working with the Emission Database (EDB) Swedish Meteorological and Hydrological Institute, SE-601 76 Norrköping, Sweden Page47(62) Phone: +46-11-495 8000, Fax: +46-11 495 8001 Figure 3.6.7.1 Roads Restrictions You can select up to 10 Road type restrictions and up to 10 Vehicle types. There are no limitations to the number of Speed that you can select. (see 3.3.8 Using Search Keys and Pattern Matching Facilities as Search Conditions). In addition you can alter the speed by prescribing a New Speed. For example: If you have selected all roads having a signed speed 90 and then select a new speed of 70, then all roads defined as 90-roads will be selected and the emission will be calculated after reducing the speed on the roads to 70. You can use other restrictions like vehicles per day (minimum and maximum) and road length (minimum and maximum). Airviro version v3.20 Page 48(62) April 2010 3.7 Grid Presentation of Emissions In previous examples, the emissions have been estimated and presented as figures located at each individual source and summed for the entire displayed map area. In several applications, you might be interested to see the spatial distribution of the emissions indicating hot spots. The EDB provides you with the possibility of defining a grid in which all sources located in each grid square are summed and represented with a colour code. For displaying emissions as a coloured grid you have to select the Output Settings subwindow. Then, choose Grid as Output. The values for Intensity goes from -100 (black) to +100 (white), moving in the values RGB. You can use Color Fade to reduce the colours in scale of grey. The values for colour fade goes from -100 (grey) to +100 (very grey). Now, you are free to decide the resolution of the grid. There are two different ways for doing this. If you have toggled for Grid size, then you just have to define the length of the grid in the east-west direction (dx) and north-south direction (dy). These figures are given in metrical units. Your second choice is to toggle for grid number. In this case you have to define the numbers of grid squares in the east-west direction (nX) and north-south direction. The grid size will now be determined depending on the size of the map area that you have chosen. Now define the colour table and the emissions intervals corresponding to the emissions per area unit by choosing colours and levels . Colour intervals values can be integer or float numbers and by clicking on the coloured square you will be able to choose a colour from a palette. See Figure 3.7.1. In this window, the user can use the buttons Colour and Level auto range, to automatically set the scale for both items and Colour rainbow range to automatically set the rainbow scale. When ready, you click on Apply. It is worthwhile mentioning that if you define your resolution as 50*50 m and search for road emissions, then you will see a nice road map, presenting the roads in different colours classifying them depending on the traffic emissions. Airviro version v3.20 April 2010 Page 49(62) Figure 3.7.1 Output Settings: Grid Airviro version v3.20 Page 50(62) April 2010 3.8 Creating EDB Reports and displaying the Database Structures The EDB contains many different tables. It is possible to print out summaries of these tables, along with the substance and searchkey lists. Also, it is possible to create reports containing different information about the sources stored in the EDB Figure 3.8.1 Output Settings: Report Choose Reports under the Output Settings. The report subwindow will appear. PI: Remove this , which is very easy to use. First you enter the height and width for the output window. Then select colour map, intensity and colour fade. Select the characteristics of the sources (point, area, grid and road) to be included in the report. There are two different types of report: static and dynamic. The static reports can only be in Text format. The dynamic reports also include the emission figures. This can be in a text format, SKV format (more compact, and useful for exporting the data), Grid format or GIS format (these two just contain emission data - they provide two different formats that can be used for exporting the emission data to an external dispersion model or to a GIS system). For roads: Appendix Swedish Meteorological and Hydrological Institute, SE-601 76 Norrköping, Sweden Page51(62) Phone: +46-11-495 8000, Fax: +46-11 495 8001 Select Physical attribute in order to see the length, width, slope and lanes of the road sources, in the text report. By selecting Surroundings you will include in the report, the distance between buildings and buildings heights. Under Destination you have three choices of where to send the output. If you choose File then you type on File name... and specify the name of the file to save to. Under Page layout... to specify a header and footer to print on each page and to choose whether to print each record on a new page. You can also choose whether or not to print empty fields or to print the specified search conditions. If you have chosen Text, SKV, GIS or GRID format then you can choose what point, area and road attributes that you would like to be included in the report. There is also a possibility of applying a Filter to the output that can for example alter the format of the output or send it somewhere else such as directly to a floppy disk, or to another computer. Next you have to decide if you want to print empty fields, such as gaps in the substance list, etc. Usually you don’t want this. You can also disable the alphabetic sort and print the database in the order that the EDB stores them. Every member of a database is given a number by the EDB. The Output Settings sub window is used to select the information that you want to include in the report. This report generator is activated from Output menu, in EDB Module. The report output type, can only use text output. The following is a typical data report output: The following is an example of the more compact SKV output, and is usually quite suitable to export to other database programs. "X1";"Y1";"X2";"Y2";"Name";"g/s"; 1280000;6410300;0;0;"ANGEREDS VÌRMECENTRUM";0.221816; 1273730;6400380;0;0;"BEROL NOBEL MÎLN:1";0.0982328; 1280250;6406300;0;0;"BJÎRNDAMMENS HETV.";0.348568; 1271750;6402500;0;0;"CHALMERS VÌRMEC:1";0.126752; 1271751;6402501;0;0;"CHALMERS VÌRMEC:2";0.31688; 1274000;6399950;0;0;"ERICSSON RADAR:1";0.131505; 1276540;6406970;0;0;"GRAAB SÌVENÌS";17.3016; 1268600;6401600;0;0;"GÎTEBORGS STADS BOS";3.1688; 1270430;6397410;0;0;"HEDLUNDS PAPPER:1";0.00507008; 1268550;6399350;0;0;"MARCONICENTRALEN";2.24985; 1280800;6398900;0;0;"MÎLNLYCKE:1";0.522852; Airviro version v3.20 Page 52(62) April 2010 3.9 Creating Noise Reports From the Output settings sub window select Noise as Output. The Intensity values goes from -100 (black) to +100 (white), moving in the values RGB. You can use Color Fade to reduce the colours in the scale of grey. The colour fade values goes from (grey) to +100 (very grey). You must define the colour table and the emission intervals that will be used to display the information. You do that by choosing the colour and levels. Colour intervals values can be integer or float numbers and by clicking on the coloured square you will be able to choose the desired colour from a palette. In this window, the user can use the buttons Level and Color auto range to automatically set the intervals for these two items and Colour rainbow range to automatically set the rainbow scale. You can also define your own color palette by pressing the button change palette. When ready, click on Apply to save changes. Then use the Output option (menu Module EDB) to visualize the result in GIF or PDF format. Figure 3.9.1 Output Settings: Noise Appendix Swedish Meteorological and Hydrological Institute, SE-601 76 Norrköping, Sweden Page53(62) Phone: +46-11-495 8000, Fax: +46-11 495 8001 Appendix 1A: Suggested Substance List 1A.1 Inorganic Gaseous Substances (1-39) Symbol Position Gaseous Nitrogen Compounds Nitrogen oxide NO 1 Nitrogen dioxide NO2 2 (NO2 003+ NO) NOx 3 Nitric acid HNO3 4 Nitrous acid HNO2 5 Peroxyacetylnitrate PAN 6 Ammonia NH3 7 Nitrous oxide (laughing gas) N2O 8 Gaseous Sulphur Compounds Sulphur dioxide SO2 15 Sulphuric acid H2SO4 16 Sulphur trioxide SO3 17 Hydrogen sulphide H2S 18 Carbon sulphide CS2 19 Gaseous Carbon Compounds Carbon monoxide CO 25 Carbon dioxide CO2 26 Other Inorganic Gaseous Substances Ozone O3 30 Hydrochloric acid HCl 31 Hydrogen peroxide H2O2 32 1A.2 Particulate (Inorganic, Nonmetallic) Substances (40-49) Symbol Position Particulate Matter Dust 40 Soot 41 Carbon dust 42 Particulate Inorganic Substances (Nonmetallic) Ammonium 45 Nitrate 46 Sulphate 47 Airviro version v3.20 Page 54(62) April 2010 1A.3 Metals (50-69) Symbol Position Arsenic As 50 Lead Pb 51 Iron Fe 52 Cadmium Cd 53 Copper Cu 54 Chromium Cr 55 Mercury Hg 56 Manganese Mn 57 Nickel Ni 58 Vanadium V 59 Zinc Zn 60 1A.4 Organic substances (not halogens) (70-179) Symbol Position Volatile organic substances VOC 70 Total hydrocarbons HC traffic 71 Alkanes Alkanes 80 Methane 81 Ethane 82 Propane 83 Butane 84 Alkenes Alkenes 90 Ethene 91 Propene 92 Butene 93 Alkynes Alkynes 100 Acetylene 101 Aldehydes Aldehydes 110 Formaldehyde 111 Acetaldehyde 112 Butanal 113 Benzaldehyde 114 Ketones Ketones 120 Acetone 121 Alcohols Alcohols 125 Methanol 126 Appendix Swedish Meteorological and Hydrological Institute, SE-601 76 Norrköping, Sweden Page55(62) Phone: +46-11-495 8000, Fax: +46-11 495 8001 Ethanol 127 Propanol 128 Butanol 129 Phenol 132 Glycols Glycols 135 Etheneglycol 136 Propeneglycol 137 Aromatic Substances Aromatics 140 Benzene 141 (= methylbenzene) Toluene 142 (= dimethylbenzene) Xylene (total) 143 (= vinylbenzene) Styrene 144 Toluenediisocyanater TDI 145 Polycyclic Aromatic Compounds Polyaromatic compounds (PAH including substituted polyaromates) PAC 150 Polyaromatic hydrocarbons (not substituted) PAH 151 Nitric aromatic compounds nitro-PAH 152 Naphthalene 153 Anthracene 154 Phenantrene 155 Complex Solvents (Petroleum Based, not Chlorides) Solvent HC total 160 Benzine 161 Petroleum spirit 162 Vanolene 163 Naturally Emitted Hydrocarbons VOC nat. total 170 Isoprene 171 Terpenes 172 1A.5 Halogenic Organic Substances (180-249) Symbol Position Chlorinated Solvents Solvent Cl total 180 (= Dichloromethane) Methylene Chloride 181 (= Trichloromethane) Chloroform 182 (= CCl4) Carbon tetrachloride 183 Vinyl chloride 184 1,2-Dichloroethane 185 1,1,1-Trichloroethane 186 (= trichloroethylene, Tri) Trichloroethene 187 (= Perchloroethylene) Tetrachloroethene 188 Chlorine-Fluorine-Bromine-Alkanes Completely halogenated freons: Airviro version v3.20 Page 56(62) April 2010 Chlorinefluorinecarbons (total) CFC total 190 CFC-11 191 (=R12) CFC-12 192 CFC-113 193 CFC-114 194 Incompletely halogenated CFCs: (Replacement for CFC - soft freons) (R22) HCFC-22 200 Incompletely fluoridated CFCs: (C2H2F2) HFC-134a 203 Bromium-chlorine-fluorine carbons (Halons): Completely halogenated halons Halons total 210 (= CF2ClBr) BCFC-1211 211 (= CF3Br) BFC-1301 212 (=C2F2Br2) BFC-2402 213 Incompletely halogenated halons (=CHF2Br) HBFC-22B1 215 Other halogenated organic substances (=1,1,1-trichloro-2-bis(4-chlorophenyl)ethane) DDT 220 Chlordane Chlordane 221 Polychlorinated biphenyls PCB 222 Toxaphene Toxaphene 223 Dioxines Polychlorinated dibenzo-p dioxines PCDD 225 Polychlorinated dibenzo-furanes PCDF 226 Brominated dioxines Brom. dioxines 227 TCDD 228 Lindan 229 1A.6 Others (250- ) Number of vehicle kilometres vekm 250Appendix Swedish Meteorological and Hydrological Institute, SE-601 76 Norrköping, Sweden Page 57 (62) Phone: +46-11-495 8000, Fax: +46-11 495 8001 Appendix 1B: Mathematical Definitions of the Formulae Used in the EDB 1B.1 Point, Area and Grid Source Emissions In the Airviro EDB, emissions can be calculated as a function of the hour, day, weekday, month and as a function of the outdoor temperature. In order to identify non-working days when they appear in the middle of the week (e.g. when New Years Day appears on a Wednesday) the concept of day types is introduced, i.e. Day type (index) Meaning Relative occurrence during a year Monday-Thursday type (0) Ordinary working day 4/7 Friday type (5) Day before non working day 1/7 Saturday type (6) Non working day - Saturday 1/7 Sunday type (7) Non working day - Sunday 1/7 The following variables and functions are defined: Dty = day type index = {0,5,6,7} w(dty) = relative occurrence of day type dty M = index for month m= {1, 2, ..., 12} W(m) = relative occurrence of month m (approximated as 1/12) H = hour during the day = {1, 2, ..., 24}, e.g. h=12 corresponds to mean value between 11 and 12 S = scenario index T = outdoor temperature = {T1-T2, T2-T3, ..., T29-T30}. By default -30°C