Research On Seepage Characteristics Of Soil In Riparian Zone Based On Temperature Tracing Technology

The environmental impact of the water temperature of the reservoir is one of the important contents in the evaluation of the environmental impact of the water conservancy project.During the operation of the reservoir,the low-temperature water discharged causes the temperature of the natural river to change,causing the redistribution of the temperature field,which in turn affects the survival of surrounding animals and plants.Exploring the changing laws of river water and heat dynamics under different infiltration conditions will help to enhance the understanding of the impact of reservoir discharge on the ecological environment of the river,and provide theoretical basis and scientific guidance for the rational development and utilization of resources.In this paper,combined with the existing theoretical methods and the experimental research carried out,through the indoor sand trough physical model test research,a saturated-unsaturated zone coupling model is constructed based on the sand trough test research.The main research contents and results are as follows:(1)Through carrying out indoor experimental research,qualitatively analyzed the influence range and temperature transmission characteristics of different infiltration conditions on the riparian zone model.By designing different infiltration heads,different infiltration water temperatures,and different infiltration slope combinations,the test conditions were designed.Furthermore,laboratory experiments were carried out to explore the law of water and heat migration in the riparian zone,and it was found that various working conditions showed that the temperature field distribution has significant temporal and spatial differences,and the influence range is concentrated in the area around the infiltration surface,and the closer to the infiltration surface,the regional changes The more obvious,the closer the change law is to the infiltration water temperature change.As the vertical and vertical distances increase,the temperature transmission exhibits attenuation and hysteresis.The changes of the piezometer head under the influence of different infiltration conditions are compared and analyzed.Comprehensive analysis and comparison of the dynamic response characteristics of temperature field and seepage field under different infiltration conditions.(2)Quantitative analysis and calculation of the seepage velocity and water exchange volume in different areas,using VFLUX and 1DTempPro to calculate the vertical seepage velocity of the river bed,the basic calculation results of the two are relatively consistent,and they can complement each other to improve the calculation accuracy.In case A3,the lateral average exchange flow rate is 0.16～0.45 m2/d,and the exchange water volume is 0.03～0.23 m3,which is similar to the spatial heterogeneity of the temperature field distribution.With the increase of the horizontal distance,the lateral exchange volume also decays.(3)Two sets of working conditions are selected to verify and check the results of indoor test modeling,revealing the rationality and accuracy of the constructed model.The proportions of the model evaluation index NSE>0.6 are 0.93%and 89.7%,respectively.The relative error Re is less than 8%,and each evaluation index is within a reasonable range.The comprehensive characteristics show that the constructed model has a good fitting effect,and can predict and effectively characterize the temperature field changes in the riparian zone under different infiltration conditions.Change characteristics.(4)Explore the practical application of the flow-heat coupling model,analyze the characteristics of the temperature field change under the condition of a single factor change,and simulate the time-varying infiltration water head,lower temperature infiltration water temperature and permeable layer with increasing water head Three different working conditions of the boundary,combined with the indoor test group A3 carried out,analyzed the change regularity of the temperature field and seepage field,expanded and improved the experimental research content,and explored the effect of the constructed model on the actual surface water-groundwater interaction.application.