Research On The Soil And Water Loss Characteristics Of Typical Land Use Patterns In Qingshui River Basin

Non-point source pollution caused by soil erosion is one of the important factors affecting the river water quality in Qingshui River Basin.The water quality conditions are related to the water security of the people in Zhangjiakou City and the water demand for the upcoming Winter Olympics in 2022.This paper analyzes the current status of Qingshui River water quality through field sampling and data collection,and adopts a combination of runoff plot monitoring and indoor analysis to set Caragana koma,greenhouse,and apricot tree on the typical slopes of Xigou and Donggou in Chongli.The four types of runoff plots in the Badlands have analyzed the characteristics of runoff and sediment yield under different natural land cover types and different vegetation types,which will provide a theoretical reference for the management of soil and water loss and the management of the Qingshui River Basin.The main findings are as follows:(1)The seasonal condition of Qingshui River water quality is generally better than the snowmelt period in the flood season.According to the analysis of river water quality data from 2005 to 2014,the permanganate index and ammonia nitrogen of the Yanlaimiao section and the DO and the height of the Laoyazhuang section were obtained.The manganate index and ammonia nitrogen all showed a notable downward trend,and the DO content of Yanlai Temple section did not change significantly.As a whole,the water quality of the Qingshui River Basin as a whole has gradually become better,and the concentration of pollutants has gradually decreased.(2)The monthly rainfall in the slope runoff community of Chongli District shows a concentrated rainfall in summer.The monthly distribution of rainfall is uneven,mainly in June,July,August and September,accounting for 82.4% of the total annual rainfall.Far more than other months.Starting from April to May every year,the amount of rainfall has increased over time.Then from September to October,the rainfall gradually decreased,but overall it was still at a relatively high level throughout the year.(3)Under heavy rain conditions,the rain intensity of the four communities is in good agreement with the rate of production and sand production.There is a significant positive correlation between the rate of sand production and the rate of production.Among them,the correlation of Caragana community is the strongest,and the correlation coefficient of greenhouses is the smallest.After the soil moisture content reached saturation in each plot,there was a strong correlation between the production rate and the sand production rate.(4)Under moderate rain conditions,there is a good linear correlation between rainfall intensity,production rate,and sand production rate in the four communities,among which the apricot tree community has the strongest correlation.There is also a strong linear correlation between the rate of production and the rate of sand production in the four communities,with the most significant correlation in the greenhouse community.(5)Among the four communities,Caragana community has the best effect of reducing the kinetic energy of rainfall and runoff,which can effectively reduce the production flow and sediment yield of the slope and weaken the intensity of soil erosion.From the perspective of the total amount of runoff and sediment produced,the yield of greenhouses is reduced by 30%~67% compared to waste grass,and the amount of sediment produced is reduced by 35%~47%.Greenhouse community is different from traditional farmland cultivation,and it is uncovered during plant growth.At the same time,it can make better use of rainfall for irrigation,and at the same time reduce the impact of rainfall on the exposed farmland by splashing and erosion,reduce the loss of soil nutrients,and further weaken the soil erosion status of mountain slopes.To sum up,through the analysis of the water quality of the river,we have mastered the water quality changes of the Qingshui River in the past 10 years;through the analysis of the results of the slope runoff and sediment production,we have initially grasped the characteristics of soil erosion in the mountainous area and analyzed the natural rainfall in the Chongli District.The overview provides a reference for comprehensive management of soil erosion and restoration of ecological functions in Chongli District.