Hydrological studies in the White Nile State in Sudan

Abstract

The present study was aimed to study the hydrological system in the arid areas of White Nile State, Sudan using remote sensing and GIS tools. Information on topography and soils had been extracted using ASTR, Digital Elevation Model (DEM), with 90 m horizontal resolution and Sudan General Soil Map with scale 1:25,000 using digitized method to form the GIS database. Land use/cover information was derived from remotely sensed data of Land sat Thematic Mapper of the year 2014. The vegetation cover was estimated using the normalized different vegetation index (NDVI). One sub-basin was delineated using a Digital Elevation Model (DEM) and the total acreage in different slope classes was estimated. These maps were used as input variables to derive a modified Soil Conservation Service (SCS) runoff curve number. The SCS runoff curve number model was applied to estimate the runoff depth for individual storm as (return period) event and summed up to derive the annual runoff potential for the sub-basin. All morphometric and hydrological characteristics for the elected sub-basin were extracted and illustrated and given in different tables, which include the stream numbers, the shape factor of the basin, the slope condition of the basin, the streams lengths, and the basin area and so on. The total surface water (runoff) in depth and volume potential for harvesting is 1.507 mm (depth) and 309,078.09 vol m3. The results demonstrate the capability of GIS and its application for water harvesting planning over larger semiarid areas.

Keywords

• Arid and semiarid
• Hydrological modelling
• White Nile State
• Sudan
• Remote sensing