Study On Food Supply Chain Considering Water Resource Benefit And Ecological Vulnerability

Food,water and energy are interrelated and restrict each other,affecting human production,life and ecological environment.Because of the geographical difference,different kinds of grain in different regions of our country are different,which leads to the uneven distribution of grain production and consumption space.The grain trade has become an important guarantee to meet the grain demand.In the process of grain production,the irrational use of water resources,energy consumed in the process of trade and carbon emissions affect the ecological quality of our country.Food supply chain is the primary condition to ensure food trade,and food supply chain has certain fragility in physical structure,trade characteristics and ecology.In order to improve the utilization rate of water resources in the process of grain production,further explore the bond between grain,water and energy,and maintain the stability of ecological environment,this study carried out the study of food supply chain considering the benefit of water resources and ecological vulnerability.The main research contents and achievements are as follows:(1)Based on the analysis of China’s grain production and consumption in 2017,a grain supply chain network was established based on China’s main railway network,shipping routes and the Yangtze River route,taking provincial capitals and some port cities as nodes.Based on the input-output table in 2017,the inter-provincial grain trade matrix was obtained by combining grain unit price.In 2017,the output of wheat,corn,rice and soybean was 621.27 million tons,the demand for grain was 773.07 million tons,and inter-provincial grain trade was 94.42 million tons.(2)Virtual water resources were introduced to calculate the benefits of water resources transfer and energy consumption in food trade.On this basis,physical vulnerability indexes,trade vulnerability indexes and ecological vulnerability indexes of food supply chain were established to evaluate the vulnerability of food supply chain.The results show that the distribution of grain supply chain nodes is dense in our country,and the nodes in the edge of grain supply chain have high supply chain vulnerability,such as the Urumqi,Lhasa and Haikou nodes.The vulnerability of grain trade and water resources circulation in major grain export nodes is higher,such as Urumqi,Harbin,Kunming,etc.(3)A total of 19 indexes including agricultural water footprint and industrial water footprint were selected from five aspects,including water footprint,water vulnerability,ecological pressure intensity,ecological sensitivity and ecological resilience.Combined with entropy weight method and SRP model,the ecological vulnerability of supply chain nodes was analyzed.The results showed that Hohhot,Urumqi and other nodes were in highly fragile ecological areas.(4)The optimization model of grain trade was established with the goal of the lowest transportation cost,the least blue water output from water shortage area and the highest water transfer benefit of grain trade.Through comparative analysis before and after optimization,it is concluded that grain import volume decreased by 87,745,100 tons and virtual blue water output decreased by 1.327 billion cubic meters.For example,the average values of vulnerability to food trade and vulnerability to water resources circulation both decreased by 15% to 24%.The benefits of water transfer increased by about 5 billion cubic meters,that is,5 billion cubic meters of virtual blue water was saved,and 1.3 billion cubic meters of blue water was reduced in water shortage areas.As domestic food is fully utilized,energy consumption and carbon emissions have increased.The ecological vulnerability index of some nodes decreased by 5% to 9.1%,which was out of the category of high vulnerability.