云南省陆地生态系统和土地利用类型的NDVI时空变化特征

Spatial and Temporal Variation Characteristics of NDVI for Various Terrestrial Ecosystems and Land Use Types in Yunnan Province

研究不同陆地生态系统和土地利用类型的归一化植被指数(NDVI)时空变化特征,不仅可揭示基准年以来各生态系统和土地利用类型的变化情况,而且可为云南不同生态区的保护提供科学依据。基于SPOT-VEGETATION NDVI数据,利用一元回归和相关分析等方法,在ArcGIS平台下分析1999-2013年云南NDVI时空变化的基础上,以2000年云南陆地生态系统和土地利用为基准年,重点分析植被指数变化显著区域的各类陆地生态系统和土地利用类型NDVI的变化情况。结果表明,云南省国土面积六成以上区域的植被指数出现了显著的上升趋势,局部地区出现了下降趋势,其中,昆明、玉溪、红河、大理、德宏5个州(市)和曲靖市南部植被指数上升不明显,显著下降的区域主要是滇中地区;普洱市出现大面积连片上升区。植被指数上升的主要生态类型是农田、森林和草地生态系统,下降的是聚落、水体和湿地生态系统;从土地利用类型看,植被指数上升面积比例较高的是旱地、有林地、灌木林、疏林地和高覆盖度草地,下降面积比例较高的是城镇用地和其他建设用地。分析结果可为云南省生态保护提供科学依据。

The study on the spatial-temporal variation characteristics of the normalized vegetation index(NDVI)of different terrestrial ecosystems and land use types can not only reveal the changes of each ecosystem and land use type since the base year,but also provide scientific basis for the protection of different ecological zones.Based on the SPOT-VEGETATION NDVI data from 1999 to 2013,this paper analyzes the temporal and spatial variation characteristics of NDVI on ArcGIS platform by using unitary regression and correlation analysis methods.Then taking the year 2000 as the base year,we analyze the changes of land ecosystem and land use type NDVI in the areas with significant changes of vegetation index.The results suggest that the vegetation index of more than 60%of the areas in Yunnan province shows a significant upward trend over the years except a downward trend in some areas,of which the increasing trend is not obvious in Kunming,Yuxi,Honghe,Dali,Dehong and the southern Qujing city while the significant decreasing trend is found in central part of Yunnan.Pu’er city has a large area with NDVI value rising.The NDVI increases mainly in farm land,forest and grassland,but decreased in settlement,water body and wetland ecosystems.From the perspective of land use types,the NDVI increases in dry land,woodland,shrubs land,open-forest land and high coverage grassland considerably,but decreases in urban land and other construction land to some extent.The above analysis results may provide scientific basis for ecological environmental protection in Yunnan province.