Study On Groundwater And Surface Water Optimal Allocation In Huinong Canal-well Irrigation Of Ningxia

This paper for canal well combined with area surface water, groundwater allocation optimization problem in Yellow River irrigation area of Ningxia Huinong.Create an experimental observation base for canal wells in Ligang, systematically study on water balance, numerical simulation of groundwater, canals and wells water resources optimal proportion of surface water, groundwater optimal allocation problem.lt provides the theoretical basis for the irrigation district water saving technological transformation. The results were as follows:(1) Through the summary of the results of previous studies, this paper has studied the dynamic of the optimization of surface water groundwater allocation.(2) We selected of Huinong irrigation district as the key research area irrigation area. The main collection and analysis are about regional crop planting proportion, crop irrigation system, hydrological and geological conditions,the four water conversion relationship, the development o f social economy.(3)Through the research of experimental area, summarize and analyze groundwater flow and groundwater dynamic change, the main factors of dynamic change of groundwater is the Canal seepage, irrigation, artificial exploitation and evaporation, and the influence of geological factors is ot obvious.(4) Using the analysis of water balance, positive equilibrium of groundwater, groundwater recharge is 85000 m3, groundwater excretion is76800 m3,groundwater recharge is greater than excretion 8200 m3, The positive balance of groundwater positively make irrigation area soil secondary salinization occurred(5) Generalizing hydrogeological conditions of the study area, the source term data and hydrogeological parameter initial value is imported into the groundwater numerical simulation software of Visual Modflow.establish the groundwater simulation model, after the model calibration and verification, the permeability coefficient of the model for 9.5m/d, the water supply of degree 0.2.By comparing the model to simulate the groundwater depth and the actual groundwater depth,showing that the correlation coefficient of the model to simulate the groundwater depth and the actual groundwater depth is higher,the precision of the model is relatively accurate, may carry on the simulation and prediction of groundwater irrigation district.(6) Through the Visual Modflow groundwater simulation model and well and canal water optimal allocation model, get the optimal ratio of canal well water is 2.1, crop planting ratio of 0.9, can keep the groundwater in ecological safety buried deep 1.8-3m within and irrigation economic benefit maximum.