基于InVEST模型的太行山淇河流域土壤侵蚀特征研究

基于土地利用数据、数字高程模型数据(DEM)、土壤类型数据、降雨数据、植被覆盖指数(NDVI),结合地理信息系统(GIS)和遥感,计算降雨侵蚀力因子(R)、土壤可蚀性因子(K)、植被覆盖因子(C)、水土保护措施因子(P),借助InVEST模型对淇河流域2015年山地生态系统的土壤侵蚀进行研究。结果表明:(1)淇河流域微度侵蚀、轻度侵蚀、中度侵蚀、强烈侵蚀、极强烈侵蚀和剧烈侵蚀面积分别为932. 80、617. 13、282. 46、159. 58、141. 64和93. 84 km~2;土壤侵蚀总量为7 225 839. 54 t,平均土壤侵蚀模数为32. 45 t/(hm~2·a);(2)在各土地利用类型中,土壤侵蚀主要发生在林地、草地和耕地。草地和林地多分布在地形起伏度较大的高海拔区,潜在的土壤侵蚀量较大,土壤侵蚀强度也较大。虽然未利用地占流域总面积很小,但侵蚀模数最大;(3)淇河流域土壤侵蚀与坡度、海拔和地形起伏度等地形因子具有密切关系,土壤侵蚀模数随着海拔的升高先增大后降低,海拔在1 200 m处达到峰值,土壤侵蚀模数随着坡度和地形起伏度的增加而不断增大。坡度和起伏度越大,坡面土壤的不稳定性愈大,在外力作用下发生下移的可能性就愈大。海拔600～1 200 m、坡度大于15°、地形起伏度70～500 m的区域土壤侵蚀状况严重,是土壤侵蚀防治的重点区。土壤侵蚀是山地生态脆弱性响应的重要指标,山地流域的土壤侵蚀研究对评估区域生态环境质量有重要意义。

Study on Soil Erosion Characteristics of Qihe Watershed in Taihang Mountains Based on the InVEST Model

Abstract：The study is based on land use data, digital elevation model data(DEM), agrotype data, rainfall data, Normal Differential Vegetation Index(NDVI), combined with geographic information system(GIS) and Remote sensing technique,to calculate Rainfall Erosivity Factor(R), soil erodibility factor(K), vegetation cover factor(C), soil and water conservation measure factor(P), With the help of InVEST model,the soil erosion characteristics of the mountain ecosystem in Qihe river basin was studied in 2015.The results showed that:(1) The area of micro erosion, mild erosion, moderate erosion, strength erosion, extreme erosion and severe erosion are 932.80 km2, 617.13, 282.46, 159.58, 141.64 and 93.84 km², respectively. The total amount of soil erosion was 7 225 839.54 t, the average soil erosion modulus is 32.45 t/(hm²·a);(2)The soil erosion status of each land use type was analyzed,Soil erosion occurs mainly in woodland, grassland and cultivated land.Grassland and woodland are mostly distributed in high elevation areas with large undulating topography. The potential soil erosion is larger and the soil erosion intensity is larger. Although the total area of unused land is small, but the erosion modulus is the largest;(3)Soil erosion in Qihe river basin is closely related to terrain factors such as slope, altitude and terrain undulation,The soil erosion modulus increased first and then decreased with the elevation, and the soil erosion modulus reached the peak at the altitude of 1 200 m, and the soil erosion modulus increased with the increase of the slope and the relief.With the increase of the slope and the relief, the instability of slope soil becomes larger, and the possibility of downward displacement under external force becomes larger;Soil erosion is serious in areas with altitude of 600-1 200 m, slope over 15 degrees and relief degree of 700-500 m, which is the key areas to control soil erosion.Soil erosion is an important indicator for the response of mountain ecological vulnerability. The study of soil erosion in mountainous watershed is of great significance for assessing the quality of regional eco-environment.