Study on soil moisture distribution of the Gash Delta Spate Irrigation System, Sudan

The Gash Delta spate irrigation system (GDSIS) with a net command area of about 100,000 ha is the largest spate irrigation system in Sudan. Annually one third of the net command area is prepared before the flood season and irrigated during the flood period from July to September. The portion of the irrigated area, which is considered as well irrigated, is allocated to farmers for cultivation of crop and it depends on the moisture stored in the soil from the single irrigation. Classification of the irrigated area as well irrigated and poorly irrigated has been done based on experience. Hence, a scientific approach that can help in estimating the soil moisture is essential. This study deals with the estimation of soil moisture distribution based on remote sensing. A simple single-band and multiband indices at the end of flood period are used to show flooded area and the relationship between the flooded area and soil moisture distribution at the early cultivation period estimated by satellite-based Surface Energy Balance Algorithm for Land (SEBAL) is discussed. The result shows the flooded area can be used as a good index to specify well irrigated area