伊犁河谷土壤水力侵蚀的时空变化研究  

Temporal and spatial dynamics of soil water erosion in the Yili Valley

作　　者：许尔琪[1] 张红旗[1] 董光龙[1,2] 

机构地区：[1]中国科学院地理科学与资源研究所陆地表层格局与模拟重点实验室,北京100101 [2]中国科学院大学,北京100049

出　　处：《资源科学》2016年第7期1203-1211,共9页Resources Science

基　　金：国家科技支撑计划项目(2014BAC15B03)

摘　　要：为定量化评估多因子对伊犁河谷土壤侵蚀的影响及其联合效应,本文应用修正土壤流失方程,估算近30年来(1985-2000年和2000-2015两个时段)伊犁河谷土壤水力侵蚀的时空变化,分析降雨、植被盖度和土地利用各因子对土壤侵蚀变化的作用。结果表明:研究区总体上土壤侵蚀状况较轻,以微度侵蚀为主,面积占比达到83.99%,强度侵蚀等级以上的面积占比仅为2.25%,零星分布于南、北、中天山的局部地区;严重土壤侵蚀主要分布在低覆盖度的草地。对比两个时段,研究区的土壤侵蚀呈总体改善但局部恶化的趋势,轻度侵蚀等级以上的面积都显著减少。从1985-2000年到2000-2015年,伊犁河谷的降雨侵蚀力明显增加,而植被覆盖与管理因子和水土保持因子的数值则显著减少,耦合三者的时空变化,其对伊犁河谷土壤侵蚀的影响以负效应为主。Temporal changes in soil water erosion factors have not satisfactorily been considered by previous studies into water erosion estimation. To quantitatively assess the individual impact of multiple factors and their temporally and spatially combined effects on water soil erosion,we calculated the soil water erosion volume in the Yili Valley using the Revised Universal Soil Loss Equation. Temporal and spatial change in soil water erosion in the last 30 years（1985 to 2000 and2000 to 2015）was estimated and the impact of three factors（rainfall,vegetation cover and land use）on soil erosion volume was assessed. We found that soil erosion in the study area was relatively slight. The proportion of area suffering from microerosion reached 83.99%. The areas of slight erosion and moderate erosion accounted for 11.10% and 2.60% of total erosion,respectively.In contrast,the proportion of area with severe erosion was only 2.25% and scattered in southern,middle and northern Tianshan. The area of severe soil erosion is predominately grassland with low vegetation cover. When comparing soil erosion volumes for the Yili Valley across the two time frames,soil erosion characteristics showed an overall improved but locally worsening trend. The area above the light erosion degree significantly decreased. From 1985 to 2000 to 2000 to 2015,the rainfall erosivity factor in the study area increased but the cover management factor and conservation support practice factor decreased. This indicates a negatively combined impact of temporal and spatial change on soil erosion in the Yili Valley. Soil water erosion in the Yili Valley has improved from the first period（1985 to 2000）to the second period（2000 to 2015）.

关 键 词：土壤侵蚀 RUSLE方程 伊犁河谷 时空变化 

分 类 号：S157[农业科学—土壤学]