【摘要】 新疆是典型的干旱地区,生态环境极为脆弱,及时准确地了解其生态环境变化具有重要意义。本文选择干旱区绿洲城市乌鲁木齐市为研究区,利用2004年、2016年的同月份遥感影像数据,通过计算遥感生态指数(RSEI),分别从现状、空间分布、重心、景观特征、驱动因素等角度展开分析。结果表明:①2004—2016年,遥感生态指数从0.341增长至0.400,上升了17.24%,其中绿度(NDVI)、湿度(WET)和地表温度(LST)表现一定程度的上升,干度(NDBSI)表现为下降趋势;②生态指数等级划分中,主要以较低、中等水平为主,该类区域面积增长明显;生态指数等级变化,主要以不变、变好为主,其中生态指数增长的区域以上升1个等级为主;③不同类型的生态指数重心发生了偏移,低生态指数区的重心转移距离最长,达到2.82 km,较低生态指数区和高生态指数区的重心转移距离相对较短;④不同类型的遥感生态指数景观格局发生变化,斑块形状复杂性增强,空间连接性和集聚性显著。本文分析了乌鲁木齐市生态指数空间特征及变化规律,指出整个城市生态系统在近13年中没有出现大范围生态环境恶化的现象,总体向好的趋势发展,但仍有较大的上升空间。生态指数的变化与城市扩张联系紧密。更多还原

【Abstract】 Xinjiang Uyghur Autonomous Region is a typical arid area, and its ecological environment is extremely fragile. It is of great significance to understand its ecological environment changes in a timely and accurate manner.This study chose the oasis city Urumqi in Xinjiang as the research area and used the remote sensing images from the same month of 2004 and 2016 to calculate the remote sensing ecological index(RSEI), and analyze the present situation, spatial distribution,center of gravity, landscape features, and driving factors of change of RSEI. The results show that:(1) In 2004—2016, the average remote sensing ecological index value increased from 0.341 to0.400, an increase of 17.24%. Normalized Difference Vegetation Index(NDVI), Wetness(WET),and Land Surface Temperature(LST) showed a certain degree of increase, and Normalized Difference Build-up Soil Index(NDBSI) showed a downward trend;(2) With the classification of ecological index values, the main part of the study area fell within poor and medium ecological index classes. The total area of these classes is obviously growing.The classes mainly remained unchanged or improved, and the areas with improvements of ecological index mainly moved up for one class;(3) The center of gravity of all types of ecological index classes shifted, and the distance of gravity center shift of the poor ecological index class was the longest, reaching 2.82 km. The distance of shift was relatively small for other classes;(4) Landscape pattern of different types of remote sensing ecological indices changed, complexity of shape of patches increased, the spatial connectivity and agglomeration were significant.This study analyzed the spatial characteristics and changes of the ecological index and found that the process of gradual change of the ecosystem under the premise of maintaining stability with human activities is closely related to urban expansion.更多还原