Use of GIS for catchment modelling and dynamic atlas for information management and dissemination: a case study

Abstract

River Juba and Shabelle catchments are the source of the two most important rivers in Somalia. They are the source of water for irrigation and it is the food basket for many Somalis living in the southern part of Somalia. There exists inadequate baseline data, information and knowledge of the water catchments in Somalia. The little data and information existing is within NGO’s working in Nairobi. Available GIS data is in the format that cannot be utilized in the field and operation level adequately because of its perceived complex nature. The study was carried out with the aim of using Geographical Information System (GIS) to perform catchment modeling and finally using Dynamic atlas software as tool for information and data management. The tool was meant to disseminate data and information in a way that can be used by the stakeholders or anybody. In this study also some of the data derived from catchment modeling and other auxiliary data collected was used to build the Atlas. The catchment modeling and visualization was done using ArcGIS. GIS procedures which include clipping, mosaicking, creating hillshade, referencing re-projection, topology checking, overlay operations was used to prepare data. Some of the results obtained include river catchment characteristics, drainage basins, catchment area, stream network and maps which include major drainage basins map, sub-basins map, Hillshade map, percentage slope and finally the topography (elevation) map of the catchment. The results of this project have shown how GIS can be used to determine river catchment characteristics by building a catchment modeling. It is therefore recommended that Dynamic Atlas be adopted as an information management as it enables information and data sharing. The Stakeholders should also be trained on how to use dynamic Atlas