Sustainability Evaluation And Regulation Of Grain Production Resources Utilization In The Yellow River Basin Considering Water Footprint And Carbon Footprint

Grain security is the foundation of social and national stability.The pursuit of grain yield to ensure food security has resulted in heavy dependence of grain production on water resources,agricultural inputs(such as chemical fertilizers,pesticides,agricultural films,seeds)and other energy inputs(such as irrigation power consumption and fossil energy input of agricultural machinery).Extensive utilization of resources has resulted in increasing water pressure,serious non-point source pollution,declining grain production capacity,also a lot of greenhouse gases.Promoting efficient and sustainable use of resources is the basis for ensuring stable and sustainable grain production and grain security.Therefore,under the premise of low-carbon strategic orientation and grain security,it is urgent to comprehensively consider the utilization of water and energy(including agricultural inputs and energy inputs),and carry out the sustainable evaluation and regulation research on the grain production resources utilization.The Yellow River Basin(YRB)is a major grain production base in China.However,the basin is facing serious water,ecological,environmental problems.To effectively promote the high-quality development and implement the strategic guidance of the ecological priority,green and low-carbon development of the YRB,it is particularly necessary to carry out the study on sustainable regulation of grain production resources utilization in the YRB considering the sustainable utilization of water and energy resources.This study proposed a research system of grain production regulation at the watershed scale that comprehensively considered food security and sustainable development.The system estimated grain production and consumption,simulated grain trade characteristics.By introducing effective tools to estimate the water consumption and greenhouse gas emissions:water footprint and carbon footprint,resources utilization characteristics of watershed grain production was analyzed.Then,a sustainability evaluation method of grain production resources utilization based on water and carbon footprint was established,and finally,the regulation of watershed grain production considering the sustainable utilization of resources was carried out.This research could provide a reference for national and watershed grain trade planning,policy making about resource utilization,and the sustainable development of society,economy,water resources,and environment.Main results are as follows.(1)By using the SPAM 2010(Spatial Production Allocation Model)global spatial data set to estimate the watershed grain production,and by estimating four grain consumption(ration,fodder,industrial and seed grain)respectively,the watershed grain supply and demand characteristics were analyzed,which provided an idea for the analysis of grain supply and demand in the data shortage area.Results showed that:The annual average yield of wheat,corn,and rice in the YRB accounts for about 16%.14%and 0.66%of the national yield,respectively.The annual average consumption of wheat,corn,and rice in the YRB accounts for about 15%.8%and 4%of the national consumption,respectively.(2)An inter-provincial grain trade path simulation method based on the balance of grain supply-demand combined with the multi-regional input-output model was proposed.This method better takes the current logistics characteristics into consideration,and the simulation results are closer to the reality.Results showed that:the inter-provincial grain trade in mainland China is increasing year to year.Based on the characteristic of inter-provincial grain trade,the weight method of net grain yield was proposed and used to estimate the characteristics of external watershed grain trade of the YRB.Then,the minimum grain transportation cost model was established to quantify the internal watershed grain trade.This study is beneficial for revealing the current grain trade routes in mainland China and the YRB,providing reference for efficient future grain transportation.Taking wheat,corn and rice into consideration,the grain trade volume within the YRB is on the rise,and the annual net grain outflow from the YRB is about 2.1 million tons in external watershed grain trade.(3)Water footprint of the grain growth stage as well as the virtual water footprint characteristics were calculated and analyzed to reveal the influences of grain growth and trade on water resources based on concept of water footprint calculation method,the USDA SCS(U.S.Department of Agriculture Soil Conservation Method)effective precipitation calculation,Penman-Monteith formula,etc.Results showed that:the total water footprint of the grain growth per unit mass in Ningxia and Inner Mongolia is relatively higher,while that in Henan and Shandong is relatively lower.Considering three grains,the annual average virtual water inflow associated with the external watershed grain trade in the YRB is about 37×108 m3.(4)According to the concept of carbon footprint,the carbon footprint of each carbon emission factor including grain tillage,sowing,irrigation,fertilization,pesticides,agricultural film,machinery use and so on were quantified.Results indicated that the input of nitrogen fertilizer and irrigation water resources in wheat production should be controlled in Inner Mongolia,while the input of chemical fertilizer and agricultural film in corn production should be controlled in Gansu and Shaanxi.Considering three grains,the annual average embodied carbon outflow associated with the external watershed grain trade in the basin is about 560,000 tons.(5)By comprehensive applying benchmarking analysis,generalized data envelopment analysis and other methods,a sustainability evaluation method of grain production resources utilization was proposed and established based on water and carbon footprint,and it was applied to the YRB for carrying out the sustainability evaluation.The evaluation system is of generality and can accurately reflect the difference of resources input of grain production across the whole country.Basin evaluation results showed that:except for Shandong and Henan,other regions in the basin mainly present medium or relatively weak sustainability grade of resource utilization.To promote the efficient resources utilization of grain production,the basin should further formulate resources conservation policies considering different local conditions.(6)Considering sustainable use of resources,a watershed grain production regulation model was established,with the goal of minimizing the total basin water footprint and carbon footprint of grain growth stage,constraints of grain security,red line of total water use,and sown area,and decision-making variable of sown area.The model could provide feasible schemes for water saving,carbon emission reduction and high-quality development of the basin.Results showed that:under the premise of ensuring grain security,considering two grains:wheat and corn,the sown area could reduce about 247 thousand hectares,leading to the reduce of 154,900 tons carbon emission and 3.34×108 m3 irrigation water at the same time.The YRB should further develop suitable planting and water use schemes based on local policies to better use the reduced sown area and irrigation water.