湘中低山丘陵区土壤侵蚀时空变化及其对环境干扰的响应

为揭示土壤侵蚀时空变化及其对环境干扰的响应,综合运用CSLE、熵权TOPSIS、障碍度模型等分析方法,剖析湘中丘陵区2000—2015年土壤侵蚀的时空变化和诊断土壤侵蚀风险的障碍因素并提出针对性建议。结果表明:(1)湘中低山丘陵区土壤侵蚀以微度侵蚀为主,面积占比在50%以上;(2)2000—2015年土壤侵蚀流失量呈减小趋势,约下降了49.75%;(3)土壤侵蚀强度和风险在空间上有显著差异,高值区主要集中在湘中丘陵区西部和南部;(4)湘中低山丘陵区土壤侵蚀主要是由人为干扰引起的,其贡献率达73.76%,是自然干扰的3.62倍,未来应坚持自然恢复为主,避免过度人工干扰。综上,湘中低山丘陵区土壤侵蚀以微度侵蚀为主,存在显著的时空变化特征,人为干扰是其变化的关键驱动力。

Temporal and Spatial Variation of Soil Erosion and Its Response to Environmental Disturbances in the Hilly Region of Central Hunan

In order to reveal the soil erosion spatiotemporal changes and its response to environmental interference, we used CSLE, entropy weight TOPSIS, obstacle degree model and other analysis methods to quantify soil erosion and identify its influencing factors in central Hunan Province from 2000 to 2015, which is mainly covered by low mountains and hills. The results show that:(1)more than 50% of the region was eroded in minor degrees;(2)the soil erosion volumes decreased by 49.75% from 2000 to 2015;(3)the soil erosion intensity and risk varied differently in space, with high values in the west and south of this region;(4)soil erosion in the study area was mainly caused by human disturbance, which was 3.62 times greater contribution(73.76%)than that of natural disturbance. In the future, it is necessary to focus on natural recovery and avoid excessive artificial interference. In general, soil erosion in the middle and low mountain and hilly areas of Hunan Province is mainly slight erosion, there are significant temporal and spatial variation characteristics, and human disturbance is the key driving force of soil erorion change.