重庆市都市区NDMI时空分异特征研究

NDMI是研究城市化进程中城市生态环境的一个重要指标和过程参数，研究NDMI时空分异特征重在把握人为干扰环境的力度。利用重庆市都市区TM遥感数据，综合运用地形位指数、分布指数、平面重心模型以及重心迁移速率等方法，研究分析NDMI时空数量结构分布特征。研究结果表明:随着建设用地面积扩展和城市发展，地表水汽含量总体减少；各等级NDMI之间以相邻转换最为突出；低水汽指数区域集中分布在300～500 m的平地和100～400 m的低缓坡区域，高水汽指数在1，2级地形位的分布指数最优。研究旨在为重庆市都市区维持区域生态系统的稳定性和改善人居环境质量提供参考和依据。

Research on the Spatiotemporal Differentiation Characteristics of NDMI in Chongqing Metropolitan Area

Normalized Difference Moisture Index (NDMI) is one of the important indexes and process parameters as used to examine urban ecological environment in urbanization process. The key to study the spatiotemporal differentiation characteristics of NDMI is to determine the interference from human. We took the TM data of Chongqing metropolitan area as the remote sensing data source. These methods including terrain niche index, distribution index, plane center model and the center migration rate were used to analyze the spatiotemporal distribution characteristics of NDMI. The results showed that with the extension of construction land and the development of city, land surface moisture content generally reduced; the transfer characteristics between each grade NDMI mainly demonstrated the features with adjacent conversion; low moisture index mainly distributed in the flat with altitudes ranging from 300 m to 500 m and the gental slope with the altitudes varying from 100 m to 400 m; the highest moisture index mainly distributed in the first and the second terrain niche. These results can provide reference and basis for maintaining ecosystem stability and improving the quality of inhabited environment in Chongqing metropolitan area.