Hydraulic modelling software cannot increase the natural availability of water but it can contribute significantly to improvements in the performance of the water utilities. In Europe, where water utilities have faced continuous cost pressures in recent years, hydraulic modelling has proved invaluable in reducing leakage and ensuring that infrastructure programs are designed as cost effectively as possible.
Wallingford Software, is the global leader in the development of water management software solutions. Wallingford Software’s products include network modelling and data management software to support planning and operations in water distribution, sewerage provision, river management and coastal engineering. In this article, we provide a brief overview of the application of water and wastewater modelling and indicate the rapid growth of its application in the Middle East and North Africa.
The Middle East and North Africa remains a challenging environment for the water engineer. A 1999 report from the World Bank highlighted a number of issues facing water users in the region:
- Growing water shortages
- Uneven water distribution
- Over exploitation of water resources
- Deteriorating water quality
- Rising water supply and sanitation costs
- Inadequate water and sanitation access
- Low technical efficiency of urban water supply
The report concluded by emphasising the importance of improving utility performance, defining the investment requirement and improving water allocation.
Hydraulic modelling is already going some way to achieve these objectives. Wallingford Software’s water management solutions are already supporting the region’s utilities and their consultants in Qatar, UAE, Kuwait, and Bahrain as they seek to achieve their objectives through improvements in the planning and management of their water networks.
Computer simulation of a water system provides an effective means to design new systems, and investigate and optimise existing systems without disturbing the real system and causing problems for existing users. To be effective the model must be based on sound data and field verified in order to have confidence that the simulation reflects the real system behaviour. By modelling the water/waste water or river system, it is possible to gain a full understanding of its hydraulic behaviour. The model can then be used as a tool to plan new infrastructure improvements, develop operational maintenance strategies and proactively manage the system.
Application of Modelling
In water supply and distribution modelling, the model should simulate the variations in flow and pressure in the potable water supply pressurised pipe network. It should represent the dynamic operation of the pumping stations, valves, control valves and reservoirs. In wastewater modelling the simulation should comprise a sewer and/or storm water collection system, consisting of closed pipes, open channels, and ancillary structures such as weirs, orifices and pump (lift) stations. Typically, the network would link all the relevant above ground catchment areas and pass the flow to the terminal pumping station or sewerage treatment works. In river modelling, the simulation is of the movement of water in open channel systems including rivers, irrigation and drainage channels and estuaries, taking account of the effect of hydraulic features such as structures, floodplains, embankments and levees.
Once a model is built, it is possible to assess the impact of change whether it is initiated by structural, geographic, meteorological or operational events. In this way, it is possible to use hydraulic models to plan new infrastructure developments (to support urbanisation), to alter existing network structures (in reaction to changes in demand or the impact of weather patterns) or to monitor the day-to-day operational performance of the network.
Modelling software is easier to use
Improvements in modelling software owe much to the increasing power of the desktop PC, which underpins the development of today’s powerful modelling systems. Once, even simple models were painstakingly built by experts in primitive computer languages or packages and at great expense. Today, the best of the current packages mean that modelling is a cost-effective approach to a wide range of water engineering decisions, with the engineer as the hands-on user.
The key improvements in the best modelling software over recent years include:
- easier model building and data input – including input from existing engineering data sources, such as GIS systems. This applies both to building the model as well as input of event data such as rainfall recorded via gauging stations and weather radar.
- better user interface – Windows style graphical user interfaces with pull down menus and clicking options means engineers can use the models themselves, without needing a computer expert to “chauffeur drive” the model.
larger models – the closer a model is to the real network, the fewer the assumptions required, and the easier it is to understand and act on the results. The increasing capacity of the best packages mean that models with tens of thousands of manholes, households or river cross sections can be built quickly and easily from direct GIS import and built-in validation.
- ease of output distribution – easy links to other PC software including mapping, word processing, and spreadsheets simplifies the understanding of the results of the model and allows it to be presented to non technical persons such as members of the public during planning discussions
- auditing and data storage – is now managed by the package itself, allowing model results to be more accountable than ever before
- modelling of real time controls – the model can include rules that change capacities and controls within the network to reflect such real-life changes at different performance levels
- acceptable run-times - with the power of PCs the best packages can use the best industry proven equations to simulate the hydraulic performance of whole cities or river catchments and still deliver results within acceptable run-times
- “sustainable models” – where once one-off models were built for a specific scheme or project, water authorities now tend to build one model for each part of the network, or even the whole network, and to maintain that model into the future
The future of modelling in the Middle East and North Africa
Against the background of rapid urbanisation, population growth and increases in water demand and its associated costs, the importance attached to the efficient operation of water support and wastewater networks is set to grow dramatically throughout the region in the coming years. Modern hydraulic software is uniquely placed to help ensure that water utilities, their consultants and engineers, optimise their resource use to the benefit of their user communities.