黄丘区特色治理开发小流域土壤侵蚀变化对景观格局演变的响应

研究土壤侵蚀与景观格局变化的关系对小流域的治理开发具有重要的指导意义.本研究以实施退耕还林草、生态农业、生态旅游及科技示范的黄土高原安塞南沟特色治理小流域为研究对象,基于GIS平台和通用土壤流失方程,分析小流域1981-2018年景观格局和土壤侵蚀量的时空演化特征,并利用主成分回归法,从斑块类型水平和景观水平两个尺度分...

Responses of soil erosion to changes in landscape pattern and its evolution in watershed in the loess hilly region under characteristic management and development

Understanding the relationship between soil erosion and the changes in landscape patterns is important for guiding the management and development of watersheds. The Nangou watershed in Ansai County, Shaanxi on the Loess Plateau, is an area with the implement of “Grain for Green”, ecological agriculture, ecological tourism and the demonstration of science and technology for landscape management. We quantified the spatial and temporal variations of landscape pattern and soil erosion from 1981 to 2018 using the GIS and the universal soil loss equation (USLE). The relationship between the soil erosion modulus and nine landscape pattern indices in three categories was analyzed using the principal component analysis at both plot and landscape levels. The results showed that, among the five landscape types, the spatial and temporal changes of cultivated land and woodland dominated the evolution of landscape patterns, which affected the concentration and distribution degree of the whole watershed. Soil erosion in the Nangou watershed decreased annually, with erosion area, erosion modulus and soil erosion intensity decreasing by 29.7%, 61.2%, and 73.4% from 1981 to 2018, respectively. The variation of cultivated land and forest land areas determined the changes of soil erosion modulus of the whole watershed. The change trend of landscape pattern index was consistent with that of soil erosion. “Grain for Green” Project was the major dri-ving force for the changes in the landscape pattern and for the reduction of soil erosion. The characteristic development and management could weaken soil erosion intensity in parts of the study area. The rational configuration of landscape types could effectively control soil erosion in a watershed. The combination of rational configuration and characteristic management could help achieve the goals for sustainable and high quality development of the watershed.