GIS-BASED IRRIGATION SUITABILITY EVALUATION OF LAPAI-AGAIE IRRIGATION SCHEME, NIGER STATE, NIGERIA

Abstract

Irrigation is one of the most important inputs for an efficient and sustainable agricultural production. Many farmers are out of jobs during the dry season and prices of locally produced food are high as a result of food scarcity during this period. The objective of this study is to map potential irrigable areas based on soil physical properties. The overall soil suitability was estimated using the weightage of each factor (slope, soil pH, soil texture, Infiltration rate, Organic carbon, Effective soil depth, Available water capacity, Cation Exchange Capacity, sodium adsorption ratio, exchangeable sodium percentage and drainage) to obtain potential irrigable sites. The data were combined using a multi-criteria decision approach to select suitable sites for irrigation. Landsat imagery with 30m resolution was used for the overall land suitability classification. The overall land suitability shows that 59.0 % of the area have been classified highly suitable (S1) for irrigation and 32.0% are moderately suitable (S2) for surface irrigation while 9.0% has been classified as marginally suitable (S3). The limiting factor that lowered the soil to S2 is mainly the organic carbon of the soil. The study shows that GIS based suitability evaluation could ease the identification and mapping of suitable land for irrigation purpose. Important management information for the study area can be easily deduced from the land suitability maps for enhancing sustainable development of agriculture. It is hoped that the information generated from this study will serve as a means of readily identifying opportunities for farmers and investors to access and put the land into suitable use.