2000-2018年皖南山区土壤侵蚀时空变化

目的] 精确评估皖南山区土壤侵蚀量并分析其时空变化特征，为区域水土流失综合治理提供科学依据。方法] 在GIS技术的支持下，利用研究区日降雨数据，30 m分辨率DEM，土壤数据和土地利用等数据，采用中国土壤流失方程（CSLE）估算皖南山区土壤侵蚀模数，并分析2000，2010和2018年近20 a研究区土壤侵蚀时空变化特征。结果] 2000—2010年土壤侵蚀模数增加了963.96 t/（km²·a），土壤侵蚀强度面积向高强度等级转移；2010—2018年土壤侵蚀模数减少了781.22 t/（km²·a），土壤侵蚀强度面积由高向低转移，总体上土壤侵蚀变化呈先增后减的趋势。皖南山区3期土壤侵蚀空间分布格局基本一致，池州市和铜陵市东南侧以及黄山市周边区域是水土流失重点防治区域。研究区内耕地以微度和轻度侵蚀为主，林地以中度及以下侵蚀为主，2010—2018年耕地和林地中度及以上侵蚀面积减小，水土保持措施成效显著。结论] 近年来皖南山区土壤侵蚀强度呈先增加后减少的趋势，总体上以轻度侵蚀为主，后续的水土流失治理仍需要加强。

Spatio-temporal Changes of Soil Erosion in Mountainous Area of Southern Anhui Province from 2000 to 2018

Objective] Soil erosion in mountainous areas in Southern Anhui Province was accurately assessed and its temporal and spatial characteristics were analyzed, in order to provide a basis for comprehensive management of regional soil erosion.Methods] With the support of GIS technology, the daily rainfall data, 30 m resolution DEM, soil data and land use data were used to estimate the soil erosion modulus in the mountainous area of Southern Anhui Province. The Chinese soil loss equation (CSLE) was employed, the temporal and spatial changes of soil erosion in the study area in 2000, 2010 and 2018 were analyzed.Results] From 2000 to 2010, the soil erosion modulus increased by 963.96 t/(km²·a), and the area of soil erosion intensity shifted to high intensity level. In contrast, from 2010 to 2018, the soil erosion modulus decreased by 781.22 t/(km²·a), the area of soil erosion intensity shifted from high to low, and the overall soil erosion change showed a trend of first increase and then decrease. The spatial distribution pattern of soil erosion in the three periods of the mountainous area in Southern Anhui Province was basically the same. The southeast side of Chizhou City, Tongling City, and the surrounding areas of Huangshan City were key areas for soil erosion prevention and control. In the study area, the cultivated land was mainly eroded slightly and lightly, while the forest land was mainly eroded at moderate or lower levels. The area of cultivated land and woodland eroded at moderate and higher level decreased in 2010-2018, and the effects of soil and water conservation measures were remarkable.Conclusion] In recent years, the intensity of soil erosion in the mountainous area of Southern Anhui Province increased first and then decreased. Generally speaking, mild erosion is the main erosion type, and the subsequent soil erosion control still needs to be strengthened.