Spatial differentiation and driving mechanism of rural water security in typical "engineering water depletion" of karst mountainous area-A lesson of Guizhou, China

Southwest China gets abundant rainfall, but in its rural areas, there is a severe shortage of water resources for irrigation and drinking. A case study was conducted in the Guizhou Province, which has the most concentrated karst distribution worldwide. The rural water security index was constructed, and Geodetector and ArcGIS were employed to systematically analyze the status quo, spatial differentiation, and driving mechanism of water security in rural areas of Guizhou in 2016. The results showed that (1) there was obvious spatial variation in the rural water security index in the study area, with only 3.85% of areas being maximally safe, and 20.51%, 35.89%, 15.38%, and 24.36% being sub-optimally safe, moderately safe, unsafe, and extremely unsafe, respectively. The spatial distribution of the rural water security index, it generally coincides with a gradual decay from the economically developed areas to the periphery. The water security of the geographical environment is inferior to those of domestic water and water for agricultural production. (2) For Guizhou Province, economic and social factors, such as the disposable income of rural residents and the incidence of impoverishment, were critical factors influencing rural water security. The critical influencing factors vary greatly among prefectures; however, there are some common factors that affect rural water security, such as the incidence of impoverishment, the penetration rate of rural piped water, the percentage of primary industry, and the percentage of karst area. The maximum value of the interactive driver of the percentage of groundwater and the disposable income of rural residents was 0.812, indicating that the interaction between the high percentage of groundwater caused by karst development and the low disposable income of rural residents was the primary reason for the low rural water security. (3) Rural water security was largely influenced by poor socioeconomic development, resulting in a low level of security and the availability of public water facilities and domestic water in rural areas. Significant improvements in rural water security depend on ameliorating the water security of agricultural production and domestic water, rather than improving the geo-environmental conditions of water resources at extremely high costs.