The spatial sensitivity analysis of land irrigation suitability evaluation based on groundwater data of Xinjiang inland river basin

Abstract

Land Suitability Evaluation (LSE) is an important reference for land use and development decision. Multi-criterion decision making (MCDM) based on GIS is a convenient and efficient evaluation method. Sensitivity is a general method of validating and calibrating the results of MCDM to enhance the understanding of LSE results and to make correct planning decisions. In MCDM based on analytic hierarchy process (AHP), the weight of criteria determined by pairwise comparison is often the biggest factor causing uncertainty. In the process of MCDM, weight can be directly changed by adjusting the output of paired comparison matrix, or indirectly by changing the input and recalculating matrix. It is difficult for quantitative evaluation and spatial visualization of the sensitivity of corresponding weights of multi-criteria evaluation results. In this study, a comparison matrix calculation module was developed under excel environment, which was combined with ArcGIS and used one-at-a-time (OAT) technology to analyze the weight sensitivity caused by intensity of importance. It is particularly useful for the paired comparison matrix of order 4–6.The inland river basins in Xinjiang are studied as a representative. Groundwater irrigation suitability evaluation is made to promote regional agricultural development. Based on the preliminary results, the irrigation potential of agricultural groundwater was evaluated, and the proportions from S1 to S4 are 5%, 24%, 27% and 44% respectively. The sensitivity of line/row was higher when both criteria were more important, so the natural recharge modulus/slope was the most sensitive in the study. When the element value decreased or increased, S1 was relatively stable and S2 had some changes but not significant, on the contrary, S3 and S4 had significant changes.