黄土高原土地利用变化特征及其环境效应

研究目的:基于黄土高原近30余年来土地利用/植被覆盖变化(LUCC),分析该地区LUCC及其环境效应,为区域生态环境与社会经济的可持续发展政策提供科学依据。研究方法:地统计和趋势分析等。研究结果:(1)黄土高原土地利用结构整体上未发生变化,仍以草地、耕地和林地为主,但植被覆盖度提升显著;(2)黄土高原LUCC受气候变化和人类活动共同影响,影响程度存在区域性差异,其中黄土高原中部丘陵沟壑区主要由人类活动导致;(3)黄土高原LUCC对地表径流、土壤侵蚀、土壤水分及碳循环等生态环境过程将产生长期的影响,植被恢复在发挥生态效益的同时对区域生态环境产生消极的作用。研究结论:黄土高原植被生产力已接近水资源承载力阈值,提升人工植被稳定性、促进水资源平衡仍为现阶段促进黄土高原可持续发展的主要课题。

Spatial-Temporal Characteristics of Land Use Change in the Loess Plateau and Its Environmental Effects

Based on the land use/vegetation cover change (LUCC) in the Loess Plateau over the past 30 years, LUCC and its environmental effects in the region are to be analyzed to provide a scientific basis for the sustainable development policy of the regional eco-environment and social economy. This paper used the methods of geostatistics and trend analysis to study the characteristics of land use change, driving forces and environmental effects since 1980 and to explore the relationship between land use change and regional sustainable development. The results show that: 1)overall, land use structure of the Loess Plateau has not changed, grassland, farmland, and forest land are still dominant, but vegetation cover has significantly increased. 2)LUCC in the Loess Plateau are affected by climate change and human activities. There are regional differences in impact degrees, among which the hilly-gully region in the central part of the Loess Plateau is mainly caused by human activities. 3)LUCC in the Loess Plateau exerts long-term ecological and environmental impacts on the ecological environment processes such as surface runoff, soil erosion, soil moisture and carbon cycling. Vegetation restoration has negative effects on the regional ecological environment while generates ecological benefits. In conclusion, the productivity of vegetation in the Loess Plateau has approached the threshold of carrying capacity of water resources. Therefore, improving the stability of artificial vegetation and promoting the balance of water resources become the main topics for promoting sustainable development on the Loess Plateau at this stage.