The solutions allow one interface to answer a wide range of questions, rather than requiring a user to laboriously work through a range of modules or packages. Such key but separate elements of the modeling process as GIS, CAD, time series and asset management and spreadsheet information can all be accessed seamlessly through the InfoWorks interface.
Users are able to obtain raw data, undertake clean-up work and analysis, and add information that provides useful modeling functionality such as LIDAR data and flood plain or urban topography, where very detailed information is required for a model build. InfoWorks solutions can incorporate this data as part of the build process and re-use it as part of the information for the modeling results.
Integration also extends to hydrological and hydraulic data, which can be extremely differentiated in some software packages. Hydrological data on rainfall runoff, soil moisture accounting and other antecedent conditions, and hydraulic information such as flows and velocities, can be accommodated seamlessly to create a whole-catchment model, rather than needing to import the results from a hydrological model to a hydraulic one to obtain a complete picture.
The same principle of integration applies to 1D and 2D mapping, which is now available for both InfoWorks CS and InfoWorks RS. 2D modeling is an emerging technology that enables highly-accurate depiction of overland flows in complex systems such as urban areas or very varied terrain. Many applications simply provide links between 1D and 2D models, but Wallingford Software’s approach has been to create a single model that allows users to choose which areas to represent in 1D, as appropriate, and which to model in higher-order 2D as required.
The solutions also enable integration between river and urban models through the Open MI interface, a European standard for data exchange that enables models to be linked. InfoWorks RS focuses on rivers and floodplains, and InfoWorks CS on urban drainage pipe networks, but through this medium the two can be examined in an integrated way.
For example, a recent project in the south of the UK optimized a highly-complex real-time control system to ensure that wastewater flows through the Bournemouth sewer system could not pollute the river to which treated flows were discharged. OpenMI was used to link wastewater and river models to achieve highly-sensitive real-time control.
In the study area, conditions in the river directly influenced the sewer system, so an integrated model was required. Bournemouth is a large and technically complex catchment monitored by an extensive real-time control (RTC) system, for which the main component is an online storage tunnel, activated by a penstock. The RTC controls the sewer system depending on conditions in the river where the sewer discharges, so there was a clear need for an integrated modeling approach.
The model focused on one penstock that was the key element in the system controlling all of the flows from the bottom of the interceptor sewer into the wastewater treatment works and storm tanks, as well as flows to and from the storm tanks. The penstock is opened or closed depending on whether the monitoring results indicate that levels of ammonia in the river are above or below a 1mg/litre target.
With the development of OpenMI it became possible to undertake parallel integrated catchment simulation with the data from InfoWorks CS linked to InfoWorks RS, the river model. This meant modelers were able to examine variables that could not be studied previously, and undertake a range of modeling not previously possible.
The parallel integrated catchment simulation used ran the river and sewer models together with timestep by timestep feedback of data to enable the RTC to be properly linked to the river ammonia concentrations.
The solutions’ integrative abilities also extend to water quality and pollution and sediment transportation modeling, which are treated as separate concepts in many modeling packages. Historically, this made sense because many models focused simply on flows and levels, but as environmental requirements have tightened and legislation has accumulated, accurate and integrated modeling is becoming an increasingly urgent requirement. This means there is a need to model these disparate elements in a way that acknowledges the links between them.
For instance, Kuala Lumpur has constructed ‘smart’ tunnels that are used as part of the road system on dry days but act as channels for flows during storms. General water resources issues, sediment control, and siltation are challenges due to the large-scale and rapid development that is taking place.
InfoWorks RS allows modeling of the movement of sediment by representing accurately the flows of a watercourse at all its stages and structures. Mathematical equations suitable for both cohesive and non-cohesive sediments are used to compute whether sediment is stable, being deposited, or being picked up.
Because InfoWorks RS can, as an option, examine water quality issues over time in a watercourse, it can be used to model nutrient (and other pollutant) levels, and to examine whether the results are within or outside acceptable boundaries. Kuala Lumpur will probably also provide the first use of integrated 1D and 2D flood modeling.
Integration also gives the ability to optimize storage capacity once stormwater retention systems have been constructed. Very heavy flows in combined stormwater and wastewater systems that exceed treatment works’ capacities can enter river systems untreated or partially untreated. A great deal of work has been undertaken around the world constructing detention tanks and storage basins, but once there is significant storage capacity within a system it becomes important to be able to compare runoff volumes in a range of ways, in order to optimize the storage system and possibly enable real-time modeling.
A recent example in Australia integrated InfoWorks CS with two other software packages to considerable effect. A housing development north of Melbourne, Australia was proposing a range of sustainable runoff and drainage solutions to provide water quality treatment and limit the development flows from the site.
A number of strict criteria existed, relating to flows and distance from the road as well as a variety of quality requirements.
The stormwater system design process involved taking into account a number of interrelated elements to arrive at the correct sizing for the retention ponds, all of which interacted with each other.
The two other solutions were used to resolve water quality issues and size the treatment systems, and to determine the road grading so that the stormwater drainage pipework could be designed.
InfoWorks CS was then used to model the critical flows. Stormwater drain data was imported from one of the solutions, and the final model was imported into InfoWorks to project the terrain and provide level and area data. The internal pipe networks were modeled to convey a one in five year storm. Overland flow paths were modeled to convey a one in 100 year storm, and all storm durations were run to determine the critical storm for both situations.
In an operational environment, if a model has been created for offline investigation and planning it is very easy to then bring this into the operational arena, undertaking operational modeling without the need to re-calibrate the same datasets. This is of particular use for such things as flood forecasting, and optimization of stormwater systems.
A good example of this is the Bang Pakong project in Thailand, which integrated flood and water quality modeling and water resource management. The river barrage needs to retain water for supply, but has to be operated in such a way as not to cause flooding, which occurs regularly in the river basin. The model was used from a design perspective and went on to direct day-to-day operation of the barrage.
The 1990s dam, constructed by Thailand’s Royal Irrigation Department (RID), regulated river flows and minimized salinity intrusion. Optmum operation of the dam to satisfy the different stakeholders’ needs meant setting appropriate gate operation rules, but determining these and monitoring the conditions to apply to them required investment in telemetry.
RID therefore decided to set up a telemetry system for flood forecasting and flood warning in the Bang Pakong river basin. The project objectives included development of a real-time telemetry system for flood forecasting and early warning to reduce flood damage, as a decision-making tool for efficient water resources management, and to enable operation of the Bang Pakong dam to resolve conflicts of interest.
Wallingford Software developed the telemetry system using its InfoWorks RS and FloodWorks modeling software. There are 17 telemetry points around the basin, monitoring rainfall, water levels, gate positions, and water quality (salinity, dissolved oxygen, pH, and temperature) and feeding into the control room at the dam.
The modeling and flood warning aspects of the project are also based on InfoWorks RS and FloodWorks. Existing Wallingford Software models of the river basin were imported into InfoWorks RS with additional cross-sectional data and topographical details, geo-referenced and linked to a detailed ground model. The model was then further developed to ensure stability over a range of flows and tidal levels, and water quality aspects were added.
Use of a real time flood forecasting and warning system has helped to alleviate flood risk concerns and reduce flood damage, and the Bang Pakong telemetry system is now helping to improve the efficiency of the Basin’s water resources