Using cartographic documents and GIS for creation a hydrodatabase. Application on Hodna Basin, Algeria

Abstract

The Hodna basin, one of the most important basins of Algeria, marks the transition between the Tellian domain in the north and the Sahara in the south. In addition, hydro-agricultural developments (construction of dams for irrigation) still have very important impacts on the functioning and hydrogeological characteristics of the basin. The Geographic Information System (GIS) is a computerized tool for representing and analyzing all the elements that exist on Earth as well as all the events that occur there. A working methodology, which consists in representing the information collected in the form of thematic maps, was carried out using the software ArcGIS by the exploitation of the database data available at the level of the organizations [Directorate of Water Resources (DRE) and the National Agency of Water Resources (ANRH)]. The approach adopted consists of three (03) steps: The first step is the preparation of the data required for the simulation (small sub-watersheds used as simulation units of hydrological processes) ,and here we particularly mention the mapping of the physical description of the basin that influence hydrological processes such as topography, geology, rainfall, river system, groundwater resources and soil type, this, first of all of the construction of the Digital Terrain Model (DTM).The second step is the determination of a database for hydrology (BD), followed by the creation of models of a Geographic Database (MBDG) for the watershed and for the assessment and estimation of groundwater and surface water in the Hodna basin in the third step.