Crop-land Suitability Analysis Using GIS and Remote Sensing in Nyandarua

Abstract

Land suitability analysis is a method of land evaluation, which measures the degree of appropriateness of land for a certain use. The aim of this research was to identify and delineate the land that can best support potatoes, using GIS-based Multi Criteria Evaluation technique and Remote Sensing. The study was carried out in Nyandarua County in Kenya. Agriculture is the mainstay of local economy in the study area, but the production is very low because some of the crops being introduced are not doing well. There is need therefore to identify and delineate suitable areas for growing various crops to achieve maximum potential yield. Three suitability criteria i.e. soil (PH, texture, depth, drainage), climate (rainfall, temperature) and topography were evaluated based on agronomist experts opinions and FAO guideline for rainfed agriculture. An Analytical Hierarchical Process was used to determine relative importance of criteria and the resulting weights were used to construct the suitability maps/layers using GIS software. Finally, land suitability map was generated by overlaying these maps with current land cover map generated from Landsat images through supervised classification. The results of this research revealed that in the study area, 37.6% of the agricultural land is highly suitable for potatoes cultivation, 51.5% is moderately suitable and 10.9% is marginally suitable. The results can be used by the County government to advice the local farmers on the suitable areas for potatoes cultivation.