The use of remote sensing and GIS techniques with special emphasis on the use of Arc hydro data model in characterizing Atbara River watershed

Remote sensing and GIS techniques were used successfully to establish hydrological information platform for Atbara sub-basin which drains from Ethiopia and Eretria to Sudan with entire area of about 224299 Km2. The study area have strategic importance, for many reasons; rich in minerals wealth, agricultural resources, and endowed with a substantial amount of water resources but the spatial and temporal distribution of water resources is imbalance. Remote Sensing and Digital elevation models (DEMs) are known to be very useful data sources for the automated delineation of flow paths, sub watersheds and flow networks for hydrologic modeling and watershed characterization, Landsat ETM + 30 m and Digital Elevation Models SRTM 90 m data used in this project, many digital image processing techniques used to enhanced images, interpretation and extracted information from satellite images by using ERDAS imagine, wile Arc GIS and arc hydro tools were used to processing and extract information from DEMs, stream network and catchment delineation and creation of geo database. It is the main output of this project, ready made GIS layers used to complete watershed characterizations view. The results of this research present in creation Arc hydro data model, and many thematic maps for Atbara sub-basin characteristics. The use of remote sensing in the study give efficient qualitative and quantitative detailed information about geomorphologic features drainage patterns, addition to general overview for land cover and land use. Moreover, the use of Digital Elevation Models in addition to the delineation of stream network and catchment give valuable information on the pale-geography and pale-climate of the study area. River network and watersheds delineations proved that El Gash River was once joining the Atbara River and it was a part of Nile Basin System. This might indicate that pale climatic conditions in the area were wet than the present. Geo database and Arc hydro data model arranged spatial data in relationship database provide quarry option for any information about study area. Although, Arc hydro tool provide time series analysis options, this thesis restricted the use of Arc Hydro tool to the descriptive part only.The created GIS geo database was used to produce various thematic maps, mainly for; geology, geomorphology, hydrography, land cover, land use, population density, vegetation cover and rainfalls. (Author)