Study On Spatial-temporal Differences And Influencing Factors Of Agricultural Water Footprint In The Main Grain-producing Areas

Water resources are the important material basis of agricultural production.The sustainable utilization of water resources will affect the basic role of agriculture.The main grain producing areas assume the main function of agricultural production,but restricted by the practical bottlenecks such as imperfect water-saving irrigation facilities,intensified contradiction between supply and demand of water resources and deterioration of water environment,the security of grain supply is seriously threatened.The study of agricultural water footprint in main grain producing areas can provide policy basis for alleviating the pressure of agricultural water use and realizing agricultural sustainable development.Therefore,this study first takes the main grain producing areas as the research area.Based on the analysis of the current situation of agricultural development and water resources utilization,the agricultural water footprint of the main grain producing areas from 2000 to2019 is calculated by using the top-down method based on the water footprint theory.Secondly,this study analyzes the temporal evolution characteristics of agricultural water footprint by analyzing the distribution location,kurtosis and morphological extension of kernel density curve;By analyzing the scatter plot of global Moran’s index and local Moran’s index,the spatial distribution difference of agricultural water footprint is analyzed.Finally,through the model applicability test,a spatial Dubin model considering spatial effect is established to analyze the influencing factors of agricultural water footprint.The main conclusions of the study are as follows:(1)From the time series characteristics of agricultural water footprint in main grain producing areas,the overall agricultural water footprint showed an inverted "N" shape fluctuation and downward trend from 2000 to 2019,and gradually stabilized below 15 billion cubic meters.The agricultural water consumption of all provinces and regions decreased to varying degrees compared with the beginning of the period;From 2000 to 2019,the agricultural water footprint in the main grain producing areas was polarized,the overall internal difference showed a narrowing trend,and the development trend of low value provinces and regions was strong.From the perspective of agricultural virtual water trade,the volume of agricultural virtual water trade in the main grain producing areas increased slowly and then decreased from 2000 to 2019,and most provinces and regions began to curb the output of agricultural virtual water.(2)From the spatial distribution difference of agricultural water footprint in main grain producing areas,the agricultural water footprint in the main grain producing areas shows significant positive spatial autocorrelation globally,and shows the spatial aggregation characteristics of high-high aggregation and low-low aggregation locally,with an obvious trend of polarization.Among them,Inner Mongolia and Northeast China are in low value aggregation areas,and the agricultural water footprint is significantly lower than that in other areas,while the Huang Huai Hai area is in high value aggregation areas;The agricultural water footprint of most provinces and regions in the main grain producing areas has strong spatial dependence,and there are certain spatial barriers and path locking characteristics.(3)From the influencing factors of agricultural water footprint in main grain producing areas,policy factors,water-saving technology,social development,economic development and industrial structure adjustment can significantly inhibit the increase of agricultural water footprint,but the inhibitory effect of policy factors and water-saving technology is significantly less than other factors,while agricultural production and natural factors have a significant positive impact on agricultural water footprint.The results of decomposition effect analysis show that the negative spatial spillover effect of water-saving technology and industrial structure is strong,and the positive spatial spillover effect of agricultural production and natural factors is strong,which can significantly affect the agricultural water footprint of adjacent areas.