Author(s): Mohamed A. A. Sayed; Mohamed Bahaa Saad
Linked Author(s): Ahmed Sayed Mohamed Ahmed
Keywords: GIS; Flood management; Distributed models; Rainfall estimation; Flood forecasting; Remote sensing
Abstract: The Nile Forecasting System (NFS) was developed to provide tools and information for water resources planning and management in the Nile Basin. The tools include mathematical models for simulating flow regime of the Nile, inflow forecasting, river and reservoir routing, reservoir control, historical and real-time information about hydrological and meteorological process occurring in the whole Nile Basin. Because of the lack of adequate hydrometeorological data, the METEOSAT satellite data was utilized to obtain more detailed spatial resolution of the distribution of precipitation over the basin. A distributed hydrologic system was designed to take advantage of the satellite derived precipitation as well as known physical characteristics of the river basin from Geographic Information System (GIS). To estimate the rainfall over the Nile Basin, which is the main driving force of the hydrological models, remote sensing technology was applied. The NFS receives continuous METEOSAT satellite imagery data, and processes it to produce rainfall estimates using satellite precipitation estimation techniques. Observed real-time precipitation data is also considered as input to NFS. Precipitation estimates are computed on a grid or multiple grids of resolution of 5.5 km by 5.5 km, and used as input into a distributed hydrological modeling system being developed for the Nile Basin. The hydrological modeling system consists of water balance model, hillslope routing model, and channel model, reservoir routing model and hydrological GIS sub-system. Flows, stages and mean areal rainfall distribution over the Nile Basin are generated in real-time by the NFS and can be displayed via a user-friendly User Interface for any part of the basin and at a number of locations along the River Nile. Meanwhile, the NFS provides the decision-makers in Egypt with a timely forecast of the Nile River inflows into the High Aswan Dam. These forecasts are in a form of daily inflow traces based on the Extended Stream-Flow Prediction technique. The Decision Model for High Aswan Dam (HAD) is an operational model, which uses these traces as the driving input. Accordingly, it determines the operational strategy of the High Aswan Dam, which optimizes the function of the dam. Furthermore, as conditions change, decisions can be re-evaluated and revised as often as desired. The objective of this paper is to present different components of the NFS system and how it is used in managing high floods and supporting the decision makers in managing High Aswan Dam.
Year: 2002