Site Suitability Analysis for In Situ Rainwater Harvesting Structures Using Remote Sensing and GIS in Sheikan Locality, Sudan.

Abstract

The study was conducted in Sheikan locality in 2017 to
identify appropriate sites for Rainwater Harvesting (RWH). A systematic
identification of the appropriate sites for different RWH structures may
contribute to a better success of crop production in such areas. One
approach used to adapt to climate change is in situ water harvesting for
improved crop yields in Sheikan locality, Sudan. The main objective of
this study was to determine the suitable sites for in situ water harvesting
structures in the face of climate change through the use of GIS and
Remote Sensing techniques in Algabal and Wad Albaga areas of Sheikan
locality. A GIS based model has been developed to generate suitability
maps for In-situ RWH using multi criteria evaluation. Five suitability
criteria (soil texture, runoff depth, rainfall surplus, land cover, and slope)
were identified for in situ RWH and for each criterion, five suitability
levels were chosen (Excellent, Good, Moderate, Poor, and Unsuitable).
Weights were assigned to the criteria based on their relative importance
for RWH using an analytical hierarchy process (AHP).Using QGIS and
ArcGIS software, all criterion maps and suitability map of the study area
were prepared. Consequently, from the obtained suitability map Wad
Albaga location (semi-circular bunds) falls in good portion (844 km2
)which represents 46.04%,whereas Algabal location (terraces bunds) lies
in themoderate class (341 km2
) with 18.6%.However, Algabal location
was considered as moderate site which was attributed to the soil texture
which was sandy clay soil and was ranked as the second most important
class compared to Wad Albaga location which was sandy clay loam soil.
The obtained suitability map facilitates the identification of sites where in
situ RWH structures can be realized. The study concluded that identifying
suitable sites using GIS is cost-effective and time-saving method to
discover the most appropriate sites for RWH.