A method to assess flood risk on Danish national roads in a large area in the middle and southern part of Jutland, Denmark, was developed for the Danish Road Directorate. Flood risk has gained renewed focus due to the climate changes in recent years and extreme rain events are expected to become more frequent in the future. The assessment was primarily based on a digital terrain model (DTM) covering 7,500 km2 in a 1.6 × 1.6 m grid. The high-resolution terrain model was chosen in order to get an accurate estimation of the potential flooding in the road area and in the immediate vicinity, but also put a high requirement on the methods, hardware and software applied. The outcome of the analysis was detailed maps (as GIS layers) illustrating the location of depressions with depths, surface area and volume data for each depression. Furthermore, preferential flow paths, catchment boundaries and ranking of each depression were calculated. The ranking was based on volume of depressions compared with upstream catchment and a sensitivity analysis of the runoff coefficient. Finally, a method for assessing flood risk at a more advanced level (hydrodynamic simulation of surface and drainage) was developed and used on a specific blue spot as an example. The case study shows that upstream catchment, depressions, drainage system, and use of hydrodynamic calculations have a great influence on the result. Upstream catchments can contribute greatly to the flooding.
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Wallingford Software`s InfoWorks RS and FloodWorks software solutions have received a boost from the news that the European Commission has put forward a directive intended to help its member states to limit or prevent floods and the consequent damage to human health, the environment, infrastructure and property.
Since 1998 floods in Europe - notably the catastrophic 2002 floods in the Danube and the Elbe - have caused some 700 deaths. In all, around half a million people were displaced...
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The problem
Water companies typically keep their network asset data either in a GIS or in a number of different files of different formats and ownership; some companies use a combination of the two. The management of such data repositories is often an ongoing headache for water engineers, especially at the time of data entry – import into the database– and at the point of using the data – exporting the data from the database. These problems usually stem from the following...
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The southern Thai city of Hat Yai lies 50km north of the Malaysian border. This important commercial city began the journey to its present urban sprawl in the early 1970s and today is southern Thailand's principal town, serving as a popular tourist centre for Malaysian and Singaporean visitors from the south. Thailand's climate is equatorial in the extreme south, while the centre and north experience a tropical monsoon climate.
Most of the country has...
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Scotland has an area of roughly 79,000km2 and a population of five million. The northern highlands is the least populated area, but covers two thirds of the land, with the central lowlands the most populous zone and the fertile southern uplands dedicated mainly to farmland. In all, the country has some 50,000km of rivers and numerous lochs, including major water bodies such as Loch Lomond and Loch Katrine, which supply water to Glasgow, and Loch Ness.
With such plentiful...
Introduction
Water and life are synonymous. Communities expect to be protected from floods, to have a reliable and safe water supply, to be able to swim and fish in rivers and lakes. Stakeholders who share water ultimately compete for that water, with conflicts becoming more critical during periods of prolonged drought, when there is not enough water to go around and rationing is enforced. Population growth, industrial and economic expansion and climate change will inevitably lead to more pressure on a finite...
Introduction
The flow variations in sewers have been modelled for several years with a comparatively high degree of accuracy as far as the diurnal variations and responses to climatic conditions are concerned. However, until comparatively recently the variations in flow due to fluctuations in groundwater levels, soil storage capacity and wetness of the catchment have only been modelled in basic terms. For the past decade it has been possible to use runoff models that respond to the increasing wetness of the...
The UK’s prestigious Royal Society recently held a discussion group on the subject of Flood Management and Climate Change. With much of the Northern Hemisphere approaching the winter flooding season, we spoke to Wallingford Software’s David Fortune to find out the role of modelling in flood forecasting and flood management. He set out his ideas as follows:
We must remember first that, while we might expect more flooding as our climate changes, it is not a simple matter to predict the extent of flooding. It’s not...
Overview
In the UK, numerical Hydraulic Modelling of the urban environment, water networks and rivers plays a vital role in providing the UK Water Industry with solutions for protecting the environment, meeting UK Government and European Regulations, meeting OPEX and CAPEX business targets, and improving the efficiency of Water Companies in managing their assets.
Similarly, the UK water industry has invested heavily in GIS and asset databases. But until recently these have been under utilised by the modelling...
In December 1997, member countries of the United Nations reached agreement to reduce their total greenhouse gas emissions under the Kyoto Protocol. By 2005, all member countries will have to report on their progress. Such international action reflects the immediate need to tackle the issue of greenhouse gas emissions and their impact on climate change. As the world looks to the new millennium, government agencies are starting to implement guidelines and procedures for business to measure, reduce and report on...
1.1 Scope and Objectives
A small number of viable options are presently available for the bleaching of wood pulp (delignification and brightening) during the manufacture of pulp and paper. The use of chlorine dioxide (ClO2) in the bleaching process has largely superceded the earlier use of Cl2, or elemental chlorine, in the majority of North American pulp mills: It was discovered over a decade ago that the previous widespread use of Cl2 contributed to the production and subsequent release to the environment of...
Introduction
Increasing concerns about the potential risks of anthropogenic climate change over the past ten years have led to a series of international conferences intended to combat climate change and its adverse effects. However, the Kyoto Conference of the Parties to the Framework Convention on Climate Change (FCCC) and, more so, the conference in Buenos Aires revealed the tremendous complexity of the climate change issue, which makes consensus about necessary mitigation measures almost impossible. Not...
INTRODUCTION
1. Biological diversity (biodiversity) is essential to maintain life on earth and has important social, economic, scientific, educational, cultural, recreational and aesthetic values. In addition to its intrinsic value biodiversity determines our resilience to changing circumstances. Without adequate biodiversity, events such as climate change and pest infestations are more likely to have catastrophic effects. It is essential for maintaining the long term viability of agriculture and fisheries for...
Introduction
Pollution Prevention Guidelines to provide technical advice and guidance to staff and consultants involved in pollution-related projects. The guidelines represent state-of-the-art thinking on how to reduce pollution emissions from the production process. In many cases, the guidelines provide numerical targets for reducing pollution, as well as maximum emissions levels that are normally achievable through a combination of cleaner production and end-of-pipe treatment. The guidelines are designed to...
Air dispersion modeling has been evolving since before the 1930s. Over the last 15-25 years, strict environmental regulations and the availability of personal computers have fueled an immense growth in the use of mathematical models to predict the dispersion of air pollution plumes. Beychok`s recently published book, `Fundamentals Of Stack Gas Dispersion`, details the evolution of the widely used Gaussian air dispersion models and their inherent assumptions and constraints.
Unfortunately, many users of such...
Pressures on the environment may occur through chemical, physical and biological agents. The subject of this study is physical agents, where physical fields are examined.
Physical fields are part of the natural environment. Depending upon their properties and the surrounding conditions, physical fields are transmitted through the spaces in which we live, potentially affecting human health and nature. Human activity can add to, modify, and enhance and reduce the intensity of these fields. Furthermore, changes in...
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