丹江口库区土壤侵蚀对土地利用变化的响应

[目的]探讨土壤侵蚀对土地利用变化的响应,为库区土壤侵蚀的防治提供借鉴性意见,从而为制定保障丹江口水质安全的措施提供科学支持。[方法]利用遥感影像解译的土地利用类型(2002—2013年),分析丹江口库区土地利用变化,同时利用修正的土壤流失模型RUSLE对土壤侵蚀量进行模拟分析,探讨土壤侵蚀对土地利用变化的响应。[结果]丹江口库区在2002—2013年期间主要的土地利用变化集中在林地、耕地、灌草地之间的转移以及建设用地的扩张,具体表现为林地面积扩大了13.72%,耕地面积小幅增加了5.76%,而灌草地面积大幅减少了37.61%,建设用地增长了2.40倍。丹江口库区2002,2008,2013年均以微度侵蚀占主导。库区土壤的整体侵蚀强度减轻,但土壤侵蚀在城市扩张地区增加明显。[结论]丹江口库区的土地利用变化及土壤侵蚀强度的改变主要受退耕还林、天然林保护等政策措施和城市扩张的影响。库区的土壤侵蚀程度在总体上具有降低的趋势,但在城镇化区域,土壤侵蚀状况急剧恶化。

Response of Soil Erosion to Land Use Change in Dangjiangkou Reservoir Area

[Objective] The purpose of this study is to explore the response of soil erosion to land use changes,and to provide reference for the prevention and control of soil erosion in the reservoir area,as well as to provide scientific support for the development of measures to ensure water quality security in Danjiangkou reservoir area.[Methods] Using land use data interpreted from remote sensing images,we analyzed the land use changes in the Danjiangkou reservoir area between 2002 and 2013.Additionally,using the revised universal soil loss equation(RUSLE),we simulated soil erosion to evaluate how it may response to land use change.[Results] During 2002-2013,the main land use changes resulted from conversions among forest,farmland and shrub-grassland,as well as expansion of construction area.Specifically,forest area expanded by 13.72％,the area of farmland only increased by 5.76％.Shrub-grass land area has decreased by 37.61％.The construction area increased twice.In 2002,2008 and 2013,slight soil erosion dominated the most areas in the Danjiangkou reservoir area.In spite of the increased soil erosion intensity in construction area,the overall soil erosion intensity was reduced.[Conclusion] Implementation of grain-for-green policy,closing hillsides to facilitate afforestation,and urbanization contributed to land use and soil erosion change in the Danjiangkou reservoir area.The soil erosion in the reservoir area has a tendency to decrease in general,but in the area of urbanization,soil erosion has deteriorated sharply.