Spatial And Temporal Evolution And Comprehensive Evaluation Of Water Resources Security In Guizhou Province Based On The Perspective Of "Man-Landwater"

Water resources are the most basic natural resources in a region,and are related to the local ecological environment security and the stable development of social economy.The karst area is a “binary three-dimensional” spatial structure system composed of double aqueous media.Its special geomorphological-hydrological structure leads to the safety of water resources not only in quantity and quality,but also in the rapid conversion of surface water,soil erosion(leakage)and water abstraction.Difficulties,drinking water for humans and animals,etc.,to some extent,the vulnerability of water resources caused by special topographical conditions,poverty and shortage of surface water resources is an important feature of water resources security in karst areas.Therefore,according to the characteristics of the karst area,comprehensive consideration of the impact of natural and human factors on water resources security,the establishment of a scientific and reasonable evaluation index system,the identification of the main stress factors affecting water resources security,the protection of water resources in karst areas,optimization of water resources It is extremely important to configure and realize the sustainable development of the social economy.Based on the characteristics of hydrology and water resources in karst area,this paper constructs a water safety assessment model for karst areas based on the perspective of human(human activity intensity)-ground(geological and geomorphological characteristics)-water(water resources background conditions).The water resources safety evaluation index system was established in three aspects: background conditions,human activity intensity and geological and geomorphological characteristics.The evaluation criteria threshold was determined according to relevant standards and domestic and foreign development experience.The subjective weight was determined by analytic hierarchy process and determined by entropy method.Objective weights are then used to obtain the comprehensive weights of each index by using the Lagrangian coefficient.The multi-objective fuzzy membership function and the comprehensive index method are used to comprehensively evaluate the spatial and temporal evolution of water resources security in Guizhou Province from 2001 to 2015.Factor analysis is used to clarify its limiting factors.The specific conclusions are as follows:(1)Based on the concept model of “human-ground-water”,referring to the domestic and international water resources security evaluation index system,21 index factors are selected from three perspectives: human activity intensity,geological landform characteristics and water resources background conditions.A relatively complete and independent water resources security evaluation index system for the typical karst area of Guizhou Province was constructed,and the threshold range of each indicator evaluation level was determined according to the evaluation criteria.(2)The water resources background conditions in Guizhou Province are critical security types in most years.The intensity of human activities is a safer type,and it is increasing year by year,and gradually transforms into a safe state.The geological features of most states are in critical security.The state,and remained stable,the final integration led to the water security index in most years between 0.6-0.8,which is generally a safer type.At the same time,due to the significant decline in the industrial water consumption of 10,000 yuan and the agricultural water consumption of 10,000 yuan,although the precipitation and per capita water resources in Guizhou Province fluctuated greatly,the water resources generally developed towards the security type.(3)The water resources background conditions of the cities and prefectures in Guizhou Province are better in the northeastern part of the country,and the geological and geomorphological features are inferior in the east.The intensity of human activities is affected by the urban economy and water use efficiency.The poor areas are mainly concentrated in Guiyang City.Tongren City and Southwest Guizhou Province,the dislocation of the three in space,eventually led to a certain degree of difference in the water resources security index of Guizhou Province in time and space scale,except for Guiyang City,which has been in a critical security state,the overall performance is West Low East.High and generally improved over time.Although there are differences in the spatial and temporal scales of water resources security criteria in various cities and states in Guizhou Province,the geographical consistency of water resources background conditions and geological features are also prominent,which is related to the innate influence between the two.In general,there are 5 city and state water resources background conditions in Guizhou Province as critical safety types,8 cities and states human activity intensity is safer type,7 city and state geological features are critical safety types,5 cities and states The Water Resources Security Composite Index is a safer type.(4)The vast majority of water resources security indexes of various cities and states in Guizhou Province are positively correlated with precipitation,runoff coefficient,per capita water resources and river network density at different levels of 0.01 and 0.05,and the proportion of groundwater and surface water exploitation rate.The groundwater exploitation rate,the water consumption per 10,000 yuan of industrial output value,the water consumption per 10,000 yuan of agricultural output value,the average slope,the proportion of karst area,the average elevation,and the proportion of cultivated land area showed different degrees of negative correlation at the levels of 0.01 and 0.05.Starting from safeguarding and improving the level of water resources security,we should strengthen ecological environment management,adjust industrial structure,improve water resources utilization technology,strengthen water resources management,establish sound management measures and system guarantee systems,and ensure water resources security.