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通过对小流域的航片、土壤剖面、泥沙堆积与土地利用历史等详尽的综合对比分析 ,定量评价了土地利用变化对冲沟发生演变的影响。在长江上游安宁河干暖河谷选择了两个代表性的冲沟 ,分别对其形状和土壤流失的体积进行了详细的野外调查、测定和计算。研究结果表明 ,西昌安宁河干暖河谷的冲沟侵蚀速率高达 375吨 /公顷 /年。西昌地区数百年来景观持续演变 ,特别是 2 0世纪中期人为强烈的不合理采伐森林、过度放牧和农业垦殖 ,造成了大量冲沟系统的形成和发展。采取以控制冲沟侵蚀为主的有效水土保持措施 ,对中国青藏高原东缘干旱河谷脆弱山地环境的生态恢复与重建具有重大实践意义
By comprehensive and comparative analysis of the photos, soil profiles, sediment accumulation and land use history in small watershed, the impact of land use change on the evolution of gully has been quantitatively evaluated. Two representative gully gullies were selected in the dry and warm valleys of the Anning River in the upper reaches of the Yangtze River, and detailed field surveys, measurements and calculations were conducted on the volume of their shapes and soil loss respectively. The results show that the gully erosion rate of the Anning River in Xichang reaches as high as 375 tons / ha / year. The landscape in Xichang has been evolving for hundreds of years. Especially in the middle of the 20th century, man-made and irrational deforestation, overgrazing and agricultural reclamation led to the formation and development of a large number of gully systems. Taking effective measures of water and soil conservation, which mainly control gully erosion, has great practical significance for the ecological restoration and reconstruction of the fragile mountainous environment in the arid valley in the eastern edge of the Qinghai-Tibet Plateau