Water Resources and Seasonal Forecasting

To forecast the availability of water in a catchment or region, many factors may need to be considered such as reservoir operations and water demands from a range of users. Water allocation models are widely used when a detailed investigation is required into supply and demand and normally use a water balance approach. Some allow operations to be optimized with respect to cost, water quality or carbon emissions. Integrated catchment models are also used for forecasting future conditions, and sometimes include hydrodynamic components, particularly where water level management is important at specific locations. In contrast land surface models and distributed physical-conceptual models give a wider view of water availability at national, regional or global scale. This chapter presents an introduction to these techniques, including to the National Water Model in the USA, the principles of water resources planning and the rapidly developing area of seasonal flow forecasting for water resources applications.