基于USLE模型的祁连山国家公园土壤水力侵蚀评价  

Evaluation of soil water erosion in Qilian Mountain National Park based on USLE model

作　　者：陈豪 丁文广[1] Tanjia Binte Zafar CHEN Hao;DING Wenguang;TANJIA Binte Zafar(College of Earth and Environmental Sciences, Lanzhou University, 730000, Lanzhou, China)

机构地区：[1]兰州大学资源环境学院,兰州730000

出　　处：《中国水土保持科学》2020年第4期38-44,共7页Science of Soil and Water Conservation

基　　金：中国科学院战略性先导科技专项“祁连山生态系统变化归因与善治对策”(XDA20100102)。

摘　　要：基于通用土壤流失方程(USLE)模型对2005、2010和2015年祁连山国家公园土壤水力侵蚀情况进行计算和分析,为本地区的土壤侵蚀防治提供决策建议。经计算方法选择、插值方法对比、同类研究类比、统计分析,获得每年及平均土壤水力侵蚀空间强度与等级分类。结果表明:2005—2015年,祁连山国家公园的土壤水力侵蚀水平有所下降,土壤侵蚀量由2005年的6314.26万t/a下降至2015年的5755.59万t/a;就土壤侵蚀等级来说,研究区范围内70%的区域属于微度侵蚀,整体上土壤侵蚀强度水平较低;土壤水力侵蚀主要发生在高程为≥3600~4600 m的区域和≥8°~15°的缓坡,而高程≥4600 m的区域贡献25.67%的侵蚀量,如果冰川积雪退缩,裸土面临暴露,可能加重土壤侵蚀。因此在国家公园未来发展与土壤侵蚀防治过程中,需要严格保护3600~4600 m的高程带,以及5°~15°缓坡地带的自然环境,同时保护冰川与永久积雪。[Background]After the establishment of Qilian Mountain National Park,based on the Universal Soil Loss Equation(USLE)model,the soil water erosion in Qilian Mountain National Park in 2005,2010 and 2015 was calculated and analyzed in order to show the spatio-temporal change of soil water erosion in the area.[Methods]Based on the ULSE model,calculation method for each factor was selected according to the regional characteristics.The interpolation methods of precipitation erosivity factors were compared by choosing the method with the lowest MRE(mean relative error)when simulating rainfall amount.The R factor calculation method was selected through comparing the winter temperature in study area.And the L and S factors were obtained through calculation based on DEM.The MODIS(Moderate Resolution Imaging Spectroradiometer)vegetation index were extracted and calculated by ArcGIS and ENVI.The Chinese soil type data was used to assign values to different types of soil and the K factor was obtained.The land use information and slope data were used to calculate the P factor.R,LS,K,P,and C factors were multiplied to obtain the soil water erosion distribution of each year and the average.The zonal analyze tool of ArcGIS was used and the soil erosion at varies of elevations and slopes was analyzed.[Results]The soil erosion modulus of Qilian Mountain National Park was 1257.82 t/(km^2·a)in 2005,1094.20 t/(km^2·a)in 2010,1146.53 t/(km^2·a)in 2015.The amount of soil erosion in each year has decreased from 6134.26×10^4 t/a in 2005 to 5755.59×104 t/a in 2015.The correlation of soil erosion modulus and R showed the soil water erosion was determined by not one but all the factors.And 70%of the study area was at low-level of erosion.The area with higher level of erosion was smaller.Soil erosion mainly occurred in area higher than or equal to 3600 m and less than 4600 m and the gentle slope greater than or equal to 8°and less than 15°.The area with elevation higher than or equal to 4600 m contributed 25.67%of the amount of erosion.

关 键 词：USLE GIS 土壤水力侵蚀 祁连山国家公园 

分 类 号：S157[农业科学—土壤学]