MORPHOMETRIC ANALYSIS OF WADI DARNAH WATERSHED NE LIBYA, USING GIS TECHNIQUES
Wadi Darnah is about 586 km2 and lies in the northern portion of the Al Jabil AL Akhdar. The Wadi drains into the Mediterranean Sea. The present study incorporates a morphometric analysis of Wadi Darnah by using remote sensing and GIS techniques. Digital Elevation Model (DEM) and topographic sheets were processed in ArcGIS software. The study revealed that the drainage patterns of stream network from the basin are mainly of dendritic type which indicates homogeneity in texture and lack of structural control. The bifurcation ratio value of 4.53 indicates that the area is not much influenced by the geological structure and undisturbed drainage pattern. The study area is of the low density group basins (2.09 km-1). The elongation ratio (0.36), circularity ratio (0.14) and form factor (0.10) show elongated basin with steep relief, moderate discharge, and a long main channel. The basin has a high relief up to 850 m, which leads to a high rate of runoff but the effect of this water flow is reduced by the high infiltration capacity due to the high rate of karstification and karst features in the basin area.