Sustainable allocation of agricultural lands and water resources using suitability analysis and mathematical multi-objective programming

Abstract

This study considers simultaneously the suitable cultivable lands and water resources to optimize the cropping pattern in the Shahrekord plain of Chaharmahal-Va-Bakhtiari province, Iran. According to a semi-detailed soil survey, 120 pedons with approximate distance of 750m were excavated. Based on the pedons descriptions, 19 pedons were considered as representative. Soil samples were taken from different genetic horizons and their physicochemical properties were determined. Beside the soil map, the land suitability maps for wheat, alfalfa, potato and maize were also prepared. A goal programming model was developed to maximize the net return and cultivable area. Water and land availability, capital and non-negativity were considered as constraints (scenario 1). After preparing the land suitability maps, a constraint was defined. To do this, cultivable area for each crop greater than S1 (suitable class) and less than summation of S1, S1+S2 and S2 (moderately suitable class) was determined (scenario 2). Results indicated that based on the scenario 1, the cultivable area should be allocated to potato and alfalfa. In the scenario 2 however, all the crops remain in the cropping pattern and the highest cultivable area should be allocated to potato. In the studied region, the main constraint is water shortage while the cultivable lands are surplus. It is necessary to contribute towards the efficient use of water resources to overcome the water crisis in the region. In spite of increasing the water consumption, cultivable lands increase when the suitable land and water availability are considered simultaneously. Therefore, it seems that land suitability assessment plays an important role for successful soil management.