Study On The Optimal Allocation Of Agricultural Water Resources In Jiansanjiang Reclamation Area Based On The Combination Of Multiple Water Sources

Water resources are the basic guarantee for human survival and social development,and are fundamental for the survival of all living things.With the acceleration of modernization,people’s demand for water is increasing,and water shortage has become another problem faced by human beings.Agriculture is a major water user,and Heilongjiang Province is the largest grain production base in China.It is important to study the optimal allocation of water resources in the main grain producing areas of Heilongjiang Province to ensure the construction of the commercial grain base in Heilongjiang Province,to reasonably allocate and efficiently use the limited water resources,and to take into account the economic benefits and reasonable development of agricultural water resources.In this paper,we analyze the water supply and demand in the Jiansanjiang Reclamation Area of Heilongjiang Province as the study area,and based on this,we consider various uncertainties and complexities in the water resources system,and construct a two-stage stochastic planning model for optimal allocation of water resources to scientifically allocate the limited surface water and groundwater to each crop（rice,corn,soybean）of each farm in an efficient and reasonable manner,so as to maximize the economic benefits.The research results of this paper can be used to provide a basis for the development of an optimal allocation model for water resources in Jiansanjiang.The research results of this paper can provide a reference basis for the optimal allocation of agricultural water resources in the Jiansanjiang Reclamation Area and other regions.The main research contents and conclusions are as follows.（1）According to the characteristics of multiple water sources for water extraction in the Jiansanjiang Reclamation Area,the available water supply of surface water and groundwater in the status quo year is analyzed separately.In 2018,the total water consumption in Jiansanjiang reclamation area was 3.11 billion m3,with 2.29 billion m3 available and 820 million m3shortage,and the water available for agriculture was 2.28 billion m3 under the premise of ensuring water for living and industry.90%of the arable land in the region is planted with rice,a crop with high water demand,which is directly related to the distribution and use of agricultural water resources,and the amount of agricultural water resources directly It is necessary to study the optimal allocation of agricultural water resources in the Jiansanjiang reclamation area.（2）With the objective of maximizing economic benefits,an interval two-stage stochastic planning water resources optimization allocation model coupled with various mathematical methods is established.In view of the strong uncertainty of variables in the water resources allocation model,precipitation is treated by discrete probability distribution,water availability of each water source is treated by triangular fuzzy numbers,and the remaining uncertain parameters are treated by interval numbers.The model was established to effectively reflect the uncertainties in the water allocation system,while optimizing the allocation of agricultural water resources among different farms and crops and improving the utilization rate of agricultural water resources.The validity of the constructed model was verified by using the base data in 2018,and by comparing the original returns with the model optimization results,it was found that the model considered the incoming water under different incoming water levels,and the model optimization results could effectively improve the comprehensive water resources returns to a certain extent.（3）The model was applied to the optimal allocation of agricultural water resources in Jiansanjiang Reclamation Area in 2025,and the water allocation and shortage under different water supply levels were obtained.Under different water supply levels,the water allocation for rice increases with the increase of water supply level,and the water shortage decreases with the increase of water supply level,but under the condition of sufficient water availability,the water allocation is the optimal water allocation target,and there is no water shortage;the water allocation for corn and soybean in each farm is the optimal water allocation target,and there is no water shortage.According to the different values of the decision variable z_ij,which determines the optimal water allocation target,the model can be used to obtain multiple water allocation schemes for each farm in the reclamation area.After comparison and analysis,the optimal scheme of the reclamation area solved by the model ensures the maximum return of the agricultural water system with a small water shortage,so the model can effectively make a trade-off between the system return and the penalty risk,and provide managers with a solution that is consistent with the actual water characteristics and planting structure of the reclamation area.The model can provide managers with the optimal crop water distribution plan and the optimal water distribution plan under the conditions of system benefits and penalty risks,and provide a scientific basis for managers in the reclamation area.