Water Resources Security Evaluation In Heilongjiang Province Based On The Water-Energy-Food Nexus

Water resources are indispensable basic resources for maintaining human survival,development and ecological environment security.With the increase of population and the development of economy and society,people's demand for water resources is increasing day by day,which leads to the occurrence of water resource problems such as water shortage,water waste and water pollution.These problems also affect food security,industrial security,and ecological security.Water resources security evaluation is the premise and basis for the government to formulate water resources related laws and regulations and water resources decision-making.By carrying out the evaluation of water resources security,it can not only pretreat the possible security problems of water resources,but also provide theoretical basis for the coordinated development planning of water resources,so as to realize the sustainable development of water resources.Heilongjiang Province is an important food production base and crude oil production base in China.With the development of industry and agriculture,the problem of water resources security has become increasingly prominent,mainly manifested in water shortage and waste of water.How to alleviate the current water resources security problem in Heilongjiang Province to the sustainable development of food and energy constraints,has become an urgent problem to be solved.This dissertation is based on the water-energy-food nexus.According to the data of water resources,agriculture,industry,society and economy in Heilongjiang Province in the past 20 years,the supply and demand of water resources are summarized in Heilongjiang Province,and the relationship among water resources,energy and food are explored.Based on this,the water resources demand of Heilongjiang Province in 2020,2025,and 2030 is predicted,and the future water security level of Heilongjiang Province is evaluated from the perspective of water-energy-food nexus.The following main conclusions are obtained:(1)Water-Energy-Food Nexus in Heilongjiang Province:At present,water and food in Heilongjiang Province are interdependent and restrictive.The dependence relationship is that the food production cannot be separated from water resources.The constraint relationship is the contradiction between the increasing water demand for agricultural irrigation and the unstable total water resources,which limits the potential of grain production.Water and energy show the dependence and synergetic relationship,and the dependence relationship is constantly weakening,while the coordination relationship is constantly strengthening.The dependence relationship shows that the production and processing of energy need to consume water resources,and with the progress of water-saving technology,the amount of water resources needed to be consumed is gradually reduced,so this dependence relationship is gradually weakened.Synergetic relationship is reflected in the development and utilization of energy towards the direction of water conservation.(2)The forecast results of water resources demand in Heilongjiang Province from 2020 to 2030 show that in the future,the water demand for agriculture,domestic use and industry in Heilongjiang Province will increase.And the increase in agricultural water demand is the main reason for the increase in total water demand.From 2020 to 2030,although Heilongjiang Province will implement water-saving irrigation measure in agricultural irrigation(99% of the irrigation water is used for food irrigation),in the future,water consumption for grain irrigation will still account for about 90% of Heilongjiang's total water consumption.There are two main reasons for the increase in farmland irrigation water use: on the one hand,the proportion of irrigation in dry fields is increasing;on the other hand,the irrigation method of paddy fields is changed from well irrigation to canal irrigation(Well irrigation mainly draws groundwater for irrigation,and canal irrigation uses surface water irrigation).Although the amount of groundwater mining is reduced to a certain extent,canal irrigation uses about 20% more water than well irrigation,resulting in more water consumption.Based on the above two points,although the grain output has been increased,due to the continuous increase in agricultural irrigation water consumption,the pressure on water demand in the future will continue to increase.(3)The future water resource security degree of Heilongjiang Province is mainly affected by precipitation,and its security degree in relatively safe(level 2)between the unsafe(level 4):The degree of safety in high flow years is safety(level 2),but in low flow years,however,safety ranges between critical safety(level 3)and insecurity(level 4).The main reason for the change of water resource security degree is that water use in Heilongjiang Province is excessively dependent on precipitation under natural conditions.And the safety degree of water resources in Heilongjiang Province is under the influence of irrigation water consumption per unit area in Heilongjiang Province.Farmland irrigation water consumption per unit area is 1500-1800m3/ha,the amount of water safety degree for safer(2-2.6),farmland irrigation water consumption per unit area > 2200m3/ha,the security situation of criticality safety-no security(3-3.8).In addition,in the predicted time period,with the increase of time,the sewage centralized treatment rate,the reuse rate of industrial water and the proportion of new energy generation will gradually increase,followed by the improvement of industrial water security,domestic water security and ecological water security levels.If the industrial wastewater treatment,domestic sewage treatment,new energy development and other technologies and capital investment and policy preference are further improved,then the degree of water security will be better guaranteed.Therefore,in order to ensure the future water resources security of Heilongjiang Province,it is suggested to increase the construction and financial support of water resources conservation projects,popularize the efficient water-saving technology of agricultural irrigation,and encourage the development of water-saving new energy sources.