Article Title :
Spatial Characteristics of the Southern Al Jabal Al Akhdar Watersheds: Remote Sensing Approach
3 (2019)
37-48
Wadis , spatial analysis , Remote Sensing , GIS , Libya
The present study is to evaluate the spatial characteristics of the watersheds located in Northeast Libya, which is vital since the area is promising for surface water investment in rain-fed agriculture and pastoral activities. The study conducted using Geographical Information System (GIS) and Remote Sensing (RS) data sets: SRTM elevation data, Landsat 8 (OLI) imagery and Global Climate Monitor (GCM) data. SRTM data processed in ArcGIS, where elevations show a progressive decrease towards the South and eleven watersheds delineated (17721km2). Moreover, the perimeter, slope, aspect, and stream length of the watersheds also calculated. The hydrologic divide bounds the watersheds in the North delineated; it extends from the Southwest to the East with a length of 470km. Also, the outlets of the watersheds, which are mostly temporary lakes, those locally known as Balat assessed spatially. Landsat 8 imagery classified by Quantum GIS (QGIS), where five classes identified (alluvial plains, spreading zones, forest, grassland and bare rocks). Furthermore, precipitation and temperature data from the GCM was mapped, where the precipitation shows the highest rates in the North and gradual decrease to the South, unlike the temperature values indicate an increase towards the South and drop in the North.
Spatial characteristics of the watersheds located in Northeast Libya were analyzed in the study.
The seasonal runoff in the wadis during the rainy seasons is the surface water resource in the study area.
The outlets of the wadis mostly in the temporary lakes are topographically flat depressions located downstream.
Remote Sensing (RS) data sets: SRTM elevation data, Landsat 8 (OLI) imagery and Global Climate Monitor (GCM) data were used for the analysis.
Five land use land cover classes: alluvial plains, spreading zones, forest, Grassland and bare rock area were identified.
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