Study On Soil Water Infiltration Characteristics And Storage Technology Of Snowmelt On Slope

Object: This experiment is to explore the characteristics of slope soil moisture and the application of water conservation and storage technology in northern Xinjiang by combining field experiments and indoor simulation experiments,reveal the impact of different slope conditions and water conservation measures on slope soil moisture,and study the water conservation and storage capacity of different slope soil according to different cover conditions,and propose water storage and storage measures suitable for slope in northern Xinjiang and slope conditions most conducive to vegetation growth,And then guide the ecological construction of the region.Methods: In this study,the process of soil water movement on slope was studied by combining experiment and simulation.The observation was carried out at the experimental site of Manas Basin during the snow melting period to explore the change law of soil water content at different soil depths on the slope during the snow melting.Through soil column test,the water movement in vertical plane of soil under three radiation duration(8h,10 h,12h),two radiation intensities(sunny slope and shady slope)and two water conservation measures(black film and white film)was studied.Three slopes(10 °,20 ° and 30 °)and two water conservation measures(black film and white film)were designed through soil tank test to study the change of soil moisture content at different slope positions.The HYDRUS-2D numerical model is used to simulate the dynamic change of soil moisture at different slopes for verification,and the physical and chemical properties of soil at the same time are obtained to ensure the accuracy of the simulation.Results:(1)During the infiltration of snowmelt water,different slope conditions affect the distribution of soil water on the slope.After snow melting,the soil moisture content of the shady slope is higher than that of the sunny slope,which is more beneficial to the early spring germination of vegetation.The water storage capacity of the upper slope of the sunny slope is the worst,which is not conducive to plant growth.Compared with the shady slope,the snow on the sunny slope melts faster,the water evaporated by the snow is also faster,and the coefficient of variation(Cv)of the soil layer above 50 cm is also higher.(2)Covering the slope after snow melting can significantly increase the water retention of 0～20 cm soil layer and effectively improve the soil water content of 20～60 cm soil layer on the slope.Covering white film on the shady slope can increase the soil moisture content of 0～80cm soil layer by 27.76%,covering black film can increase the soil moisture content by 39.97%,covering white film on the sunny slope can increase the soil moisture content by 39.97%,and covering black film can increase the soil moisture content by 46.41%.(3)When the slope position is different,the distribution of soil water on the vertical plane of the slope has significant differences.After water infiltration,the change of soil water in the lower slope is significantly greater than that in the upper and middle slope.The correlation between the size of slope and the change of soil water content at the upper and lower slope positions is relatively significant,but the correlation with the middle slope position is not significant.The slope has obvious influence on the migration distance and velocity of the wet front.The most influential slope position is the downhill position.The larger the slope is,the greater the migration distance of the wet front is.(4)Different mulching treatments were carried out on the slope,and it was found that mulching could effectively improve the soil water retention effect,and the water retention of black film was better than that of white film.Compared with the non-film treatment,under the radiation duration of 8h,10 h and 12 h per day,the white film treatment increased the soil water conservation effect by 39.52%,46.63% and 48.43%respectively,and the black film treatment increased the soil water conservation effect by 46.62%,54.66%and 59.21% respectively.The effect of covering with different slopes is also different.When the slope is10 °,the soil water content under white film mulch decreases by 15.38%,and the soil water content under black film mulch decreases by 12.13%;When the slope is 20 °,it decreases by 13.03% under white film coverage and 10.77% under black film coverage;When the slope is 30 °,it decreases by 10.08% under white film and 9.53% under black film.(5)It has been verified that the HYDRUS-2D model can better simulate the soil water movement on the slope under different slopes.The model simulation results show that in the process of infiltration,the larger the slope,the greater the difference between the simulated value and the measured value,and the lower the simulation accuracy.During the evaporation process,the difference between the simulated value and the measured value at the middle slope is the largest,and the simulation accuracy of soil water content at the lower slope is higher than that at the upper slope and the middle slope.Conclusion: In the process of slope evaporation and infiltration,slope position,slope gradient and sunshine duration affect the infiltration,evaporation and migration of slope water.The slope size has a significant correlation with the change of soil moisture content at the upper and lower slope positions,but not with the middle slope position.The change of soil moisture at the lower slope position is significantly greater than that at the upper and middle slope positions.Covering can effectively increase the water retention capacity of slope soil with different slopes.The water retention capacity of black film is better than that of white film.The steeper the slope,the smaller the impact of covering on the overall water retention capacity of slope.