Assessment of agricultural water resources carrying capacity and analysis of its spatio-temporal variation in Henan Province, China

With the rapid development of global economy and society, water shortage has become a crucial limitation to the growth of many cities. The agricultural water resources carrying capacity (AWRCC) is a key indicator to judge the sustainable development of agriculture. It is necessary to quantificationally evaluate AWRCC to ensure safety of regional economic development and human being's living demand. To reasonably quantify AWRCC, this paper constructs an agricultural water resources evaluation system. CRITIC (CRiteria Importance Through Intercriteria Correlation) is introduced, and its combination with analytic hierarchy process (AHP) solves the subjectivity and randomness of weight determination. Based on the definition of AWRCC and fuzzy comprehensive evaluation (FCE), we construct support index (CCS), pressure index (CCP) and carrying capacity index (CCI) to describe the spatio-temporal variation of AWRCC in Henan Province. Applying sensitivity and correlation analyses into the AWRCC evaluation demonstrates practicality and rationality of results. It eventually provides corresponding suggestions to each city group with diverse carrying capacities. Main conclusions are as follow: (1) The per capita water consumption and agricultural water utilization rate in Henan trended to decrease yearly. The irrigation rate of cropland and the proportion of water-saving irrigation of cropland increased to a varying extent. Water resources utilization rate, cropland irrigation rate, proportion of water-saving irrigation in cropland, grain yield per unit cropland, and wetland proportion were relatively sensitive indicators and they were higher correlated with AWRCC. (2) During 2010–2020, although the agricultural water resources have been overloaded in Henan, AWRCC exhibited a slight enhancement on the temporal scale. On spatial scale, the central region had a stronger AWRCC than the surrounding cities, while the southwest region was relatively weaker, and the AWRCC of the eastern region continued to enhance. (3) According to the tertiary characteristics and spatio-temporal variation of AWRCC, cities of Henan can be roughly divided into four groups and some proposals were proposed individually to enhance the carrying capacity. The conclusion of this paper is helpful to understand the current situation of agricultural water resources in Henan and can provide a reference for the sustainable development of AWRCC.