Research On The Water-Energy-Food Nexus In Water Resource Management

Water,energy and food are indispensable basic resources for the production and life of human society.They are interdependent and closely related.Under the background of global population growth,resource shortage and ecological environment deterioration,it is of great significance for sustainable development of society to explore the interaction among water,energy and food,and to study the impact of their relationship on water resources management.Relying on the National Key Research and Development Project-Key Technologies for Coordination and Guarantee of Water-Energy-Food,and based on the life cycle theory,the flow process of water,energy and food were sorted,and the interaction between each resource and the other two resources were quantitatively analyzed.Taking Ordos in 2016 as an example,the energy consumption for water resources,the water consumption for main energy and the water consumption for food were calculated by means of literature reviewing,field investigation,statistical analysis and empirical estimation.On this basis,the evaluation index system of water resources management was constructed to evaluate and analyze the situation of water resources management in Ordos.The main contents and results are as follows:(1)On the basis of consulting relevant literature at home and abroad,according to life cycle theory,the components of life cycle of water,energy and food were divided,and the characteristics and functions of each link were summarized.Taking China in 2016 as an example,based on the e!Sankey software,the flowing sankey diagram of three kinds of resources were drawn.(2)The mutual relationship between water,energy and food were sorted out.The quantitative analysis was focused on the three issues of energy consumption for water,water consumption for energy and water consumption for food.The water-energy-food nexus diagram was drawn to express the interaction of the three resources.Taking price,waste water and exhaust gas as examples,the data indicators reflecting the interaction between water-energy-food nexus and economic system and environmental system were given,and their summation formulas were given.(3)The energy consumption for water,water consumption for energy and water consumption for food in Ordos in 2016 were calculated.The total energy consumption in the whole life cycle of water resources is 4.37×109kWh.The energy consumption of water utilization link occupies an absolute dominant position in the energy consumption of each link in the whole life cycle of water resources,which accounting for 80%.Next is the water intake link,which accounting for 12%,and the rest of the links accounted for not more than 5%.The total water consumption of coal and natural gas in the whole life cycle(excluding transportation link)is 1.95×108m3 and 2.74x107m3,respectively.The water consumption of utilization links of coal and natural gas accounts for the largest share of the total water consumption in their respective life cycle,which accounting for 86%and 98%respectively.The total water consumption in the whole life cycle of food(excluding transportation link)is 9.39×108m3.The water used for food mainly concentrates in the planting links,and the amount of water used for irrigation accounts for 99%of the total water consumption for food.(4)Starting from the connotation of the most stringent water resources management system,the influencing factors of water-energy-food nexus was introduced and the evaluation index system of water resources management was constructed.Taking Ordos as an example,the total amount,efficiency and environment were selected as three first-level indicators,and eight second-level indicators such as energy consumption per unit water resource were selected.The weights of each index were determined by analytic hierarchy process,and the comprehensive scores of water resources management were obtained by the steps of "single indicator quantification-multiple indicator synthesis-multiple criteria integration".The results show that the comprehensive score of water resources management in Ordos in 2016 is 0.6320.Compared with previous years,the situation of water resources management has improved significantly.The scores of total index,efficiency index and environmental index are 0.6184,0.6687 and 0.6145 respectively,which show that the total amount of water used is effectively controlled,the level of water use efficiency is high,and the level of water environmental protection has great potential.