Study On Suitable Water-saving Potential For Stable Ecosystem Of Irrigation Area Under The Control Of Groundwater

The shortage of water resources has become the main factor restricting the economic development of our country.The conservation and utilization of water resources is an important way to improve the utilization efficiency of water resources and alleviate the shortage of water resources at this stage.As a large agricultural country,my country has improved the utilization efficiency of agricultural water resources and promoted agriculture.Water saving is the key to efficient use of water resources.As the main form of agricultural development in my country,the irrigation area is of great significance to improve the water-saving potential of the irrigation area.The ecological system of the irrigation area is fragile.When implementing water-saving measures,the stability of the irrigation area’s ecosystem must be considered,and the water-saving potential of the irrigation area must be calculated based on the stability of the ecosystem.This paper relies on the National Natural Science Foundation of China’s“Research on the Mechanism of the Formation of Tradeable Water Volume and Water Rights Transaction Price Driven by Agricultural Water Saving in Irrigation Districts”（51979119）and takes the Yellow River irrigation area as an example.Calculate the suitable water-saving potential of the irrigation area under the premise of the stable ecosystem.The main research contents and results are as follows:（1）Research on the restraint mechanism of groundwater depth on the stability of the irrigation area’s ecosystem.The irrigation area is an organic whole of mountain-water-forest-field-lake-grass.The restriction mechanism of groundwater on each unit is analyzed,and the calculation method of suitable groundwater depth of forest-field-lake-grass is proposed,taking groundwater depth as the irrigation area.Comprehensive indicators of ecosystem stability,and construct a framework for calculating water-saving potential for ecosystem stability in irrigation areas under groundwater control.（2）Calculation of groundwater depth for stable ecosystem under multi-functional constraints in Hetao Irrigation District.Analyzed the temporal and spatial variation of groundwater depth in the Hetao Irrigation District.Gaussian fitting of the NDVI index of groundwater and vegetation in the Hetao Irrigation District was performed to determine the appropriate groundwater depth.The capillary water calculation formula was used to calculate the suitable groundwater depth in the field.Methods The suitable groundwater depth of the lake was obtained,and the groundwater depth of the stable ecosystem of Hetao Irrigation District under multi-functional constraints was finally determined to be 1.5m～2.44m.（3）The water cycle model of the Hetao Irrigation District is constructed based on the Mike she model and Mike 11 model coupling.To construct a Mike she model by downloading irrigation area elevation,soil type,Manning coefficient,initial water head,rainfall,land use and other data from the Internet,input the required ground elevation module,rainfall evaporation module,land use module,slope confluence module,river module,and The underground saturated and unsaturated module database is used to establish the water cycle model of the Hetao Irrigation District,calibrate and verify the model,and simulate the changes of the groundwater level in the Hetao Irrigation District.（4）Study on the suitable water-saving potential for the stable ecosystem of Hetao Irrigation District.According to different water-saving measures in the Hetao Irrigation District,construct a water-saving scheme set,calculate the water saving under different water-saving schemes,and use the constructed water cycle model to simulate the changes of groundwater depth in the Hetao Irrigation Area under different water-saving schemes,and stabilize the ecosystem The depth of the groundwater is compared.The calculation results show that the groundwater depth of the irrigation area after the implementation of the combined water-saving scheme F₃is 2.46m,which reaches the critical value of the groundwater depth restricted by the stability of the ecosystem of the Hetao irrigation area.