The Optimization Of China’s Food Trade Considering The Sustainability Of Water Resources—From The Perspective Of Food-Water-Energy Nexus

Influenced by climate change and social economic development,we can anticipate that the supply and demand structure of China’s food and water resources will likely change in the future.Sustainable food trade is crucial to ensure China’s food security and water security in the future.This paper studies the regulation of China’s food trade considering the sustainability of water resources,in order to improve the competitive relationship between food security and water security,and provide theoretical support for sustainable food trade decision-making in the future.Therefore,the research results are valuable for ensuring national food security.Based on the perspective of food-water-energy nexus,comprehensive consideration of food trade,virtual water flow,energy consumption and carbon emission is also helpful to provide reference for the formulation of carbon peak and carbon-neutral measures of food trade and the development strategy of sustainable society in the future.Aiming at China’s food trade,this paper constructs a calculation model of inter-city food trade and a food trade optimization model based on food security,resource sustainability and resource benefits.This paper also considers the possibility of various climate change and social development scenarios,and establishes a grain and water database based on RCP-SSP combination scenarios.Besides,this paper also describes the virtual water flow and energy consumption of food trade,and makes an in-depth study on the future food trade scheme considering the sustainability of water resources under the two conditions of free international trade and giving priority to the use of domestic food.The main results are as follows:(1)Combined with the multi-regional input-output model and high-resolution spatial distribution data of population,agricultural and water resources,a calculation model of inter-city food trade is used to obtain the high-resolution inter-city food trade data.Two possible transportation paths,the minimum transportation cost path and the shortest transportation distance path,based on the railway and ship combined transportation channel,are constructed to simulate the whole process of high-resolution current food trade.(2)This paper puts forward the systematic analytic framework of food trade,water consumption for production and energy consumption for transportation,introduces the calculation method of virtual water flow benefit in food trade,analyzes the virtual blue water flow benefit and energy consumption of food trade together with the energy consumption calculation method,and draws a high-resolution food-water-energy flow map.The results show that the current food trade objectively reduces the food security risk of China considering water shortage and improves the economic benefits of water resources use,but it is not conducive to the saving of water resources and energy in China as a whole.(3)According to the two categories of free international trade and giving priority to the use of domestic food,a food trade optimization model based on food security,resource sustainability and resource benefits is established respectively,and the current grain optimization trade is deeply studied from the three aspects of food(food import and food accumulation),water resources(water resource outputs and its resource,economy and security benefits),energy(energy consumption and carbon emission).The results show that compared with the simulation results,the total transportation cost of food trade optimization results is significantly reduced,and both the conditions of free international trade and giving priority to the use of domestic food have realized the transformation of resource benefit from wasting water resources to saving water resources.Among them,the optimized food trade under the condition of free international trade has lower transportation costs,less water resources output,energy consumption and carbon emissions,while giving priority to the use of domestic food has obvious advantages in resource benefits,economic benefits and security benefits.(4)Starting with the analysis of the future changes of many factors that affecting the supply and demand of grain and water resources,this paper constructs a relatively complete set of highresolution grain and water database under different climate change and social development scenarios supported by latitude-longitude grids,watersheds,provinces and cities,and evaluates the future food security risk in China based on the water crisis.The results show that the shortage of water resources and the water crisis related to food production in China are likely to intensify in the 21st century.The next 40 years may be the most dangerous and critical period to ensure China’s food security.(5)In this paper,a food trade optimization model based on the triple objectives of food security,water resource sustainability and water resource benefits is established.Combined with China’s food security situation and water resources supply and demand structure under different climate change and social development scenarios in the future,the food trade optimization scheme considering water resources sustainability under different climate change and social development scenarios is given through scheme calculation.Besides,this paper also reveals the transformation law of regulation objectives among various scenarios,quantifies the effect of food trade scheme from the perspective of grain,water resources and energy,and puts forward some suggestions for the development of sustainable food trade.