芦山地震灾区震后土壤侵蚀强度空间格局分析

Spatial Pattern Analysis on Soil Erosion Intensity in Lushan Earthquake Stricken Zone after Earthquake Disaster

充分考虑芦山地震灾区特殊的地貌类型,基于RUSLE模型结合多源耦合数据,定量提取了降雨侵蚀力因子(R值)、土壤可蚀性因子(K值)、坡长坡度因子(LS值)、地表覆盖与管理因子(C值)、水土保持措施因子(P值)5个因子,进而获取了2014年芦山地震灾区的震后土壤侵蚀强度,并从坡度、高程、土地利用类型方面系统地分析了不同侵蚀强度的空间分异格局。研究结果表明:①震后灾区的全年土壤侵蚀量达9504.97万t,平均土壤侵蚀模数为2248.55t/(km^2·a),总体上属于轻度侵蚀;②坡度和海拔与土壤侵蚀强度有密切关系,在坡度25~35°、海拔3000~5000m的地带土壤侵蚀最为严重;③有林地、其他林地、草地土壤侵蚀强度高于其他土地利用类型。研究成果可以为芦山地震灾区的生态环境保护及重建提供数据和决策支撑。

Based on the RUSLE model with the multi-source coupling data with the consideration of special landform types of Lushan earthquake-stricken area,five factors including rainfall erosivity factor(R value),soil erodibility factor(K value),slope length factor(LS value),surface cover and management factor(C value)and soil and water conservation measure factor(P value)were extracted quantitatively for the evaluation of soil erosion intensity after the earthquake disaster in 2014.Furthermore,it was analyzed systematically the spatial distribution patterns of soil erosion intensity from three aspects of slope,elevation and land use type.The results show that:①the annual soil erosion amount in this earthquake-stricken area is 9 504.97million tons,and the average erosion modulus is 2 248.55 t/(km^2·a),which belongs to mild erosion in general;②the intensity of soil erosion is closely related to the slope and elevation,and the soil erosion is the most serious in the zone of slope of 25~35° and elevation of 3 000 ~ 5 000m;③The soil erosion intensities of woodland,other woodland and grassland are higher than that of other land use types.The research results can provide data and decision support for ecological environment protection and reconstruction in Lushan earthquake-stricken zone.