Evaluation Of Sustainable Use Of Agricultural Water Resources In Guangdong Province Based On Water Footprint

In this study,Guangdong Province is used as the study area,and the CROPWAT model is used to calculate and analyze the blue water footprint,green water footprint and gray water footprint of major crops(rice,vegetables,peanuts,citrus oranges and bananas)in Guangdong Province from 2010 to 2020,as well as the spatial distribution;on the basis of the water footprint,agricultural water resources sustainable use evaluation indicators are selected,and the agricultural water resources sustainable use indicator system is constructed.On the basis of the water footprint,the sustainable use of agricultural water resources evaluation indicators were selected,and the sustainable use of agricultural water resources indicator system was constructed.The grey target model is used to calculate the comprehensive grey target value of sustainable agricultural water resources utilization in Guangdong Province,and to study and analyze the temporal evolution and spatial variation characteristics of sustainable agricultural water resources utilization.On this basis,corresponding countermeasures are proposed.The main conclusions are as follows:(1)Temporal evolution characteristics of water footprint of five major crops in Guangdong Province.The water footprint of major crops in Guangdong Province showed a decreasing trend from 2010 to 2020.The blue water footprint of major crops fluctuates greatly due to the fluctuation of precipitation in Guangdong Province in each year;the green water footprint and gray water footprint of major crops show a decreasing trend in general,which also indicates that Guangdong Province is constantly adjusting the agricultural planting structure to reduce the consumption of green water,and also gradually taking the path of ecological agriculture in agricultural development.Fertilizer application is decreasing,which makes the gray water footprint of fertilizer also decreasing gradually.(2)The spatial differentiation pattern of five major crops in Guangdong Province.The high values of the total water footprint of the five major crops are mainly concentrated in the eastern and northern regions of Guangdong,showing a distribution pattern of high in the northeast and low in the southwest;the high values of the total green water footprint are mainly concentrated in the western region of Guangdong;the high values of the total blue water footprint are mainly concentrated in the eastern and northern regions of Guangdong;and the high values of the total gray water footprint are mainly concentrated in the western and eastern regions of Guangdong.(3)The proportion of total water footprint of five major crops in Guangdong.The proportion of the total green water footprint of the five crops in Guangdong Province is the largest,which is closely related to the abundant rainfall in Guangdong Province;the proportion of the water footprint of the five crops is peanut > rice > citrus orange >vegetables > banana,which also shows that peanut and rice are the crops with relatively large water consumption.(4)The trend of time change in the sustainable use of agricultural water resources in Guangdong Province.2010-2020,the sustainable use of agricultural water resources in Guangdong Province is mainly concentrated in the medium level and above,and the sustainable use of agricultural water resources in Guangdong Province shows an upward trend in general during this eleven-year period,and the sustainable level of economic,social,ecological and water resources subsystems mainly shows a fluctuating upward trend.(5)The spatial distribution characteristics of the sustainable utilization level of agricultural water resources in Guangdong Province in 2020 are mainly concentrated in the level of good and above,and probably show a distribution pattern of high in the west and low in the east,while the spatial disparity of the sustainable level of comprehensive agricultural water resources is large,with the higher sustainable utilization level mainly concentrated in the western region of Guangdong,while the poor sustainable utilization level of agricultural water resources is mainly concentrated in the The higher values of sustainable utilization level are mainly concentrated in the western region of Guangdong,while the lower sustainable utilization level of agricultural water resources is mainly concentrated in the eastern region of Guangdong.This also indicates the uneven spatial and temporal distribution of precipitation in Guangdong Province,the pressure on agricultural water resources utilization caused by factors such as production methods,diversified agricultural industry structure,unreasonable agricultural water use,weak financial support related to agriculture,and the rapid increase in population.(6)Based on the calculation results of the water footprint of major crops and the sustainable utilization level of agricultural water resources,corresponding countermeasures are proposed.Innovate and develop the water resources management system to continuously improve the efficiency of water resources utilization;construct special funds related to agriculture to strengthen the development of agricultural watersaving industries;strengthen the construction of basic agricultural facilities,continuously adjust and optimize the structure of agricultural industries,and appropriately reduce some crops with high water consumption;continuously strengthen ecological agriculture and water ecology restoration and treatment to gradually reduce the gray water footprint.