黄土高原土地利用及生态系统服务时空变化特征研究

全球变化背景下,研究土地利用变化过程对生态系统的影响及相互作用机理,是全面、科学认识生态系统对人类活动和全球气候变化响应的重要支撑。本文选择我国土地利用变化典型区黄土高原为研究区域,在收集相关遥感数据基础上,采用了降水贮存量法、通用土壤流失方程和修正土壤风蚀方程等估算方法,估算了2000—2015年黄土高原水源涵养、土壤保持和防风固沙等主要生态系统服务,分析了2000—2015年黄土高原土地利用和生态系统服务时空变化特征,得出以下结论:2000—2010年黄土高原土地利用变化强度和范围较大,主要以退耕还林还草为主,2010—2015年土地利用变化整体放缓,主要以城市化为主,退耕还林还草为辅;与2000—2010年相比,2011—2015年黄土高原的水源涵养量和土壤保持量有所增加,防风固沙量有所下降,水蚀模数和风蚀模数均有所下降;黄土高原土地利用变化驱动因素主要是国家政策等人类活动因素,生态系统服务年际变化主要是由于气温和降水等气候因子的波动变化,10年或者更长尺度的变化则是由于全球气候变化和土地利用变化双重影响。本文研究可为全球变化下黄土高原生态系统的健康发展提供科技支撑和相关政策建议。

Temporal and spatial characteristics of land use and ecosystem services in the Loess Plateau

The study of the impact and interaction mechanism of land-use change on ecosystem is an important support for a comprehensive and scientific understanding of the response of ecosystem to human activities and global climate change. In this paper, the Loess Plateau, a typical area of land use change in China, is selected as the research area. Based on the collection of relevant remote sensing data, the main ecosystem services such as water conservation, soil conservation, windbreak and sand fixation in the Loess Plateau from 2000 to 2015 are estimated by using the methods of precipitation storage, Revised Universal Soil Loss Equation(RUSLE)and Revised Wind Erosion Equation(RWEQ). The main ecosystem services from 2000 to 2015 are analyzed. Based on the spatial-temporal characteristics of land use and ecosystem services in the Loess Plateau, the following conclusions are drawn:the intensity and scope of land use change in the Loess Plateau from 2000 to 2010 are relatively large, mainly in terms of returning farmland to forest and grass; the overall land use change slows down from 2010 to 2015, mainly in terms of urbanization, supplemented by returning farmland to forest and grass; compared with 2000-2010, in 2011-2015, the amount of water conservation and soil conservation in the Loess Plateau increased, the amount of wind break and sand fixation decreased, and the modulus of water erosion and wind erosion decreased; the driving factors of land use change in the Loess Plateau are mainly human activities such as national policies, and the interannual change of ecosystem services is mainly due to the fluctuation of climate factors such as temperature and precipitation, which is ten years or longer change is due to the dual effects of global climate change and land use change. Through this study, we can better reveal the process and law of human and land system and climate system change, which is conducive to the healthy development of the Loess Plateau ecosystem in the future.