石羊河流域土地覆被空间演化及驱动机制

基于石羊河流域1998年、2002年、2006年、2010年NDVI、夜间灯光数据和TM影像提取的土壤信息,以城市地表人工覆被系统为基础,计算流域土地覆被指数(Land-Cover Index,LCI),利用小波分析、空间变差函数和间隙度指数等方法构建测度模型,分析了石羊河流域地区十多年来的土地人工覆被空间演化过程和格局,然后利用回归拟合方程找出影响地区土地覆被变化的驱动机制。结果表明:LCI大范围分布受地形限制,高值区(城镇用地区域)值越来越高,而低值区(植被覆盖区域)值在2002年形成了峰值后下降,即地区城镇化水平显著提高的同时,林草覆盖率缓慢变好,并且逐渐形成区域簇群,同时地区城镇化水平受人为因素的影响较大,植被覆盖度受自然因素的影响较大。

Spatial evolution process, pattern and mechanism of land cover change in Shiyang River Basin

This article supported by remote sensing and GIS software. Using NDVI, DMSP-OLS and multi-temporal TM images covering the period 1998-2010 of Shiyang River Basin. We put forward the Land-Cover Index (LCI) based on the Vegetation-Impervious Surface-Soil (V-I-S) theory of urban land-cover system raised by Ridd and Calculate it. Then we use wavelet analysis, semivarigram and lacunarity analysis to Study the temporal and spatial scales of LCI. In order to find out the spatial distribution and evolvement rules of LCI in the last decades. Finally we attempt to utilize of the regression fit equation to identify the drive mechanism of influencing factors of land-cover change. The conclusions are obtained as follows: LCI distribution restricted by DEM in large area. The value of LCI high area (urban area) increasing, and the value of LCI low area (vegetation cover area) declining since 2002. That the level of regional urbanization significantly improved, vegetation cover slowly got better. And both of them gradually formed clusters. The level of regional urbanization greater impact by human factors, vegetation cover greater impact by natural factors simultaneously.