GIS AND AHP-BASED LAND SUITABILITY ANALYSIS FOR AGRICULTURE AND IDENTIFICATION OF POTENTIAL LAND FOR SURFACE AND LIFT IRRIGATION IN SUDURPASCHIM PROVINCE, NEPAL

Abstract

Land is a vital resource for agriculture. Due to urban sprawl, existing farmlands are being converted to other land uses. Urbanization is one of the vital elements that often involves the conversion of farmland for other purposes and the decline in the amount of available land for agriculture. Due to population growth, there is an additional pressure to increase food production. Thus, there is a need to identify land suitable for agriculture and identify the potential zone for irrigation to ensure food security. This research was conducted to identify the available land resources suitable for agriculture, surface irrigation and lift irrigation at the Sudurpaschim province in Nepal, covering 19552 square kilometer area. Land Suitability Assessment (LSA) for agriculture was conducted after considering several factors including elevation, slope, soil depth, soil pH, soil organic carbon content, soil texture, and land cover. Similarly, land suitability assessment for surface irrigation was conducted after considering factors like slope, soil depth, soil pH, soil organic carbon, soil texture, proximity to water sources, and land cover. LSA for lift irrigation was carried out based on proximity to the perennial river and the economical pumping head. LSA for agriculture and surface irrigation was conducted by using the AHP technique, along with RS, and GIS. The weights of different factors involved in the suitability assessment were determined by using the AHP technique, and among them, soil depth (criteria weight 28%), land cover (25%), slope (20%), and soil texture (17%) were the major factors determining agricultural land suitability as indicated by higher weightage in the AHP analysis. During suitability analysis for surface irrigation, proximity to water source (criteria weight 29%), soil depth (23%), slope (18%), soil texture (13%), and land cover (10%) were the major factors.