USING NILE BASIN- DECISION SUPPORT SYSTEM (NB-DSS) FOR MANAGEMENT OF KHOUR ABU HABIL WATER RESOURCES

Abstract

Being able to assess the hydrologic ability of Abu Habil catchment to satisfy its future water demands is crucial in order to plan for the future and make wise decisions. In this study a Scenario Analysis approach was used by utilizing NB-DSS model for water resource management, evaluation allocation and planning, in order to assess the impacts of possible future water demands on the water resources of Khour Abu Habil catchment. For each scenario, the main outputs of the model were analyzed: under water demands for the different water sectors and users, stream flows at the outlet of Khour Abu Habil catchment and the water possible to be stored in the reservoirs. The NB-DSS model has been successfully applied in Abu Habil river basin and its sub-basins .In addition satellite data has been used to obtain (a) present agricultural practices, (b) available suitable land for agricultural, domestic (urban and rural development) and topography, land use and other variables and (c) satellite data for climate. The Nile Basin Decision Support System (NB-DSS) is employed to provide an operative computer platform for decision makers, and is used for the evaluation of water management options and regional strategic plans. The NB-DSS comprises an information management system that performs data collection, verification, management, and visualization, and output from models estimated crop water demand (CROPWAT) for different levels of water use units. Water allocation between the various uses is simulated for a long time horizon using a deterministic model running on a monthly time step (for year 2030). The evaluation procedure of the NB-DSS was used to compare the effects of five options of strategic intervention plans of infra-structures (Construction of Haffirs, Three Dams, Turda Dam) on the basis of well-defined, comprehensive six indicators using multi-criteria approach by expressing the three major principles of Integrated Water Resources Management including: Water availability (Supply), Improvement in productivity of crops, economic (costs of development), impact and risk on downstream user, and environmental sustainability. The objective of this study is to aid in the decision-making process related to evaluation of water management scenarios and plans and implementation of intervention options to aid real-time responses to changes in water supply, allowing future developments of watershed water resources to be based on the actual relationship between the supply and demand for water. The system is tested to allocate water to different levels of water use units as a standard decision support tool by means of the actual total available water and existing (base year 2012) and expected future situations (year 2030) The model results and the analysis made show that: the runoff, if efficiently managed, should be enough to cover the water demands that range between 44361.88 Mm³ in the current scenario and 55036.02 Mm³ in the year of 2030. The major shortages are registered in Um Tagerger where annual water deficits reach 10.7 Mm³/year for the present conditions (2012) and increases to 12.9 Mm³/year in future scenarios (2030). This is followed by Khor Kajeer which is 2.6 Mm³ and goes up in future to 3.0 Mm³. The water deficit in the whole basin increases in future from a value of 13.5 Mm³ to 16.4 Mm³. The result from the Water Balance Analysis indicates that there is potential to cover to a large extent the water demands by the year 2030 if a set of recommended interventions are applied (Erection of three dams, improving, existing hydraulic infrastructure, rehabilitation of Hafirs at downstream side, and use the Turda as storage dam). The study ranked these alternative options in descending order as Haffir, Tarda, Tagor dam, Kajeer dam and UmTagerger dam. However, a tight control of the growth of the future demands will be needed, although this may be difficult in a rapidly growing developing community. To conclude the study ended by a set of recommendations for policy making and for future research.