Model And Application Of Agricultural Water Efficiency Evaluation In Lancang River-mekong Basin

The Lancang-Mekong River is the largest cross-border rivers in Southeast Asia,as countries in the distribution of water resources,the use of river basin there is a big difference,causing great difficulties to the development and utilization of water resources management and river basin.How to properly coordinate the interests of all parties,reduce conflicts and conflicts,and recognize by various countries by formulating a reasonable water resource allocation plan is a problem that needs to be solved urgently.In this paper,through the development of crop yield prediction in the Mekong River Basin under different water supply models,the assessment of irrigation water efficiency,recommended high-efficiency agricultural water supply model,to provide technical support to improve the efficiency of the use of agricultural water resources in the Mekong River Basin,and provide a basis for the development of watershed water resources allocation plan.The Mekong River Basin is a research area.This study uses the WOFOST(World Food Studies)crop growth model to predict future crop yields.In order to evaluate the impact of different water supply modes on crop yield,the WOFOST model is optimized by establishing a water-driven process data-driven model,and three water supply optimization modes are set.Mode 1 is optimizing the water supply process monthly;Mode 2 is to optimize the water supply process according to the growth period process;Mode 3 is to optimize the water supply process according to the growth period process,but use alternate day irrigation.In order to evaluate the efficiency of irrigation water use,four indexes were set up in this study,namely,irrigation contribution rate,yield growth potential,rate of water supply mode optimization,and efficiency of unit water use.Among them,the irrigation contribution rate is used to evaluate the yield after diversion irrigation and to obtain it by natural precipitation.Yield increase in yield;Yield growth potential is used to evaluate the difference between the yield after irrigation and the maximum yield under all conditions that fully meet the growth needs;the optimization rate of the water supply mode can be used to evaluate the advantages and disadvantages of the optimized water supply mode and the original water supply mode;the unit water efficiency can be used to evaluate the economic benefits that a unit volume of water can bring under a certain water supply mode.The research results show that the WOFOST model has good applicability in the Mekong River Basin,and the WOFOST model optimized by the water supply process data-driven model can be used for crop yield prediction;The established evaluation index can evaluate the advantages and disadvantages of different water supply modes,so as to achieve the priority of the water supply mode;The relationship between the water supply model and output simulation established in this paper can provide scientific basis for formulating agricultural irrigation water resource allocation schemes in the four Mekong countries.