Using GIS for Village Level Planning for Agricultural Poductivity through Water Harvesting in Semi- Arid Areas of Kitui District.

Abstract

A study was carried out to investigate the use of Geographic Information Systems for use in village Level planning in order to improve agricultural productivity through water harvesting in the semi-arid areas of Kitui district. The study considers one water catchment namely Mbusyani river and the adjacent village namely Mbusyani. The villages have a population of 50 households and 20 were selected for the study especially those close to the water sources. The key factors affecting agricultural productivity were put into consideration in developing maps using the expert approach to rank them. These key factors are namely location of rivers, existence of water harvesting structures, population along the rivers and the soil types of possible land for irrigation.

The analysis involved identifying areas where water harvesting structures would suited best in terms of availing water for irrigation in order to improve agricultural productivity. The accessibility of both the land for irrigation and the water structures in relation to the road network. The population being served by the water source. To finally check the soil type for agricultural production and how close it is to the water source. The water harvesting structure used in the study is a sand dam since it is located on the river bed. Maps for the various factors were developed and spatial analysis carried out to identify and develop spatial relationships through weighted overlays and combinations. Finally a suitability village level map built for improved agricultural productivity through water harvesting developed for use in planning.