论文部分内容阅读
应用RS/GIS技术和景观生态学研究方法,利用通用土壤流失方程(USLE)分析了黄土高原马莲河流域2000年和2007年的景观格局变化与水土流失。结果表明:马莲河流域的景观格局和水土流失方面近8 a发生了重要变化:①建设用地、水域、中高盖度草地以及林地面积增加,低盖度草地、耕地等面积减少,其中超过50%的低盖度草地补充为中高盖度草地;②斑块数量、斑块密度以及多样性指数在减小,说明斑块破碎化程度减小,生态系统趋于稳定化,生态功能逐渐增强;③土壤侵蚀总量减小12 506.76 t,水土流失明显减弱,其变化原因与当地植被恢复、人类活动、人口城镇化、建设用地增加等因素密切相关,尤其是世行项目和国家退耕还林还草政策的有效实施。
Using RS / GIS technology and landscape ecology research methods, the landscape change and soil erosion of Malianhe River Basin in 2000 and 2007 in the Loess Plateau were analyzed using the generalized soil loss equation (USLE). The results showed that significant changes occurred in the landscape pattern and soil erosion in the Malian River basin in the recent 8 years: (1) Construction land, water area, medium-high covered grassland and forest land area increased, and the area of low-coverage grassland and cultivated land decreased. More than 50% The grassland with low coverage was supplemented with grassland with medium and high coverage. The number of plaques, patch density and diversity index decreased, which indicated that the degree of plaque fragmentation decreased, the ecosystem stabilized and the ecological function gradually increased. ③The soil The total amount of erosion is reduced by 12 506.76 t, and soil erosion is obviously weakened. The reasons for the change are closely related to the local vegetation restoration, human activities, population urbanization and the increase of construction land, especially the World Bank projects and the national policy of returning farmland to forestland or grassland Effective implementation.