基于CSLE的陕北白于山土壤侵蚀现状

Soil erosion situation of Baiyu Mountain in northern Shaanxi province based on CSLE

开展土壤侵蚀定量研究,对全面了解区域水土流失现状和促进区域可持续发展至关重要。笔者以黄土高原腹地侵蚀严重的白于山地区为研究对象,采用中国土壤流失预报模型CSLE,结合ArcGIS 10.8对模型中各侵蚀因子进行量化和可视化,定量评估2020年白于山地区土壤侵蚀现状。结果表明:白于山地区2020年土壤侵蚀模数为2156.34 t/(km^(2)·a),属于轻度侵蚀;微度侵蚀的面积比例最大,占白于山地区总侵蚀面积的92.67%;由于植被覆盖度低且降雨较强,使得中度及以上土壤侵蚀主要发生在白于山中东部及中南部地区。不同土地利用类型中,草地的土壤侵蚀量最大,为614.62万t/a,并且侵蚀面积最大,占总侵蚀面积的56.90%;分析不同坡度的土壤侵蚀情况,得到>8°~25°坡度区域的土壤侵蚀量最大。建议通过优化研究区林草配置结构和加大陡坡土壤侵蚀防治措施来改善白于山的水土流失现状。

[Background]Soil erosion is one of the most serious environmental problems at present.Baiyu Mountain is a part of the Loess Plateau,where the loess is exposed and the soil erosion is severe,and the ecological environment is fragile.It is very important to carry out quantitative research on soil erosion for the comprehensive understanding of the current situation of regional soil and water loss and to promote regional sustainable development,whichmay provide scientific suggestions for subsequent soil erosion control.In this study,the Baiyu Mountain area with severe erosion in the hinterland of the Loess Plateau is taken as the research area.[Methods]The Chinese soil loss equation(CSLE)was used in combination with ArcGIS 10.8 to quantify and visualize the erosion factors in the model,and quantitatively evaluate the soil erosion status of Baiyu Mountain in 2020.The results of the first National Water Conservancy Survey conducted by the Ministry of Water Resources during 2011 and 2012 were compared with the estimated results of the CSLE model to verify the rationality of the model.Regional statistics and ArcGIS were combined to analyze the erosion conditions under different land use types and slopes in the Baiyu Mountain area,so as to further determine the main areas of soil erosion.[Results]1)The soil erosion modulus in the Baiyu Mountain area was 2156.34 t/(km^(2)·a),belonging to the grade of mild erosion,and the soil erosion area was 2.86×10^(4)km^(2);the area of slight erosion accounted for the largest proportion with 92.67%of the total erosion area of Baiyu Mountain.Due to the low vegetation coverage and strong rainfall,moderate and above soil erosion mainly occurred in the central and central-southern area of Baiyu Mountain.2)Among the different land use types,the soil erosion amount of grassland was the largest,which was 614.62×10^(4)t/a,and the eroded area was the largest,accounting for 56.90%of the total eroded area.Secondly,the erosion amount of cultivated land was 167.89×10^(4)t/a.The small amount of forest land erosion was 60.75×10^(4)t/a.3)Within a certain range,the amount of soil erosion usually increased with the increase of slope gradient.The maximum soil erosion amount in Baiyu Mountain was 284.01×10^(4)t/a in the slope>15°-25°.The soil erosion amount rate of>25°-35°slope area was 187.05×10^(4)t/a.In addition,the slope area>8°-25°accounted for 58.38%of the total area of Baiyu Mountain,but its soil erosion amount accounted for 75.85%of the total soil erosion.[Conclusions]The soil erosion status in Baiyu Mountain has been improved by optimizing the forest and grass configuration structure in the study area and strengthening the prevention and control of soil erosion on steep slopes.This result can provide a theoretical basis for soil erosion control in Baiyu Mountain area in the future.