重庆市土地利用变化特征的遥感分析（英）

使用TM影像和参与性农村评估获取的数据,研究了1986-2005年间重庆市土地利用变化的时空特征,结果表明:1986-1997年间,耕地转为建设用地、草地和未利用地开垦为耕地或林地是重庆市3个最大的土地转换类型,而1997-2005年,这一转换则体现为耕地退为林地、建设占用耕地、耕地转换为水体和未利用地开垦为耕地或林地.建设用地的扩张以耕地的减少为代价,而同时又有大量的草地和未利用地开垦成耕地.林地的快速增加来源于草地和未利用地的开发和建设用地的复垦.同时,三峡工程的修建也使得沿江及其支流的部分耕地转换为水域.然而,驱动重庆土地利用变化的这一特征,其主要原因在于政策安排和土地利用覆盖的原始格局.前者决定短时期内重庆土地利用变化的基本方向,而后者则在大的环境背景下,决定重庆土地利用变化异质性的根本性力量.研究有助于理解后备资源短缺下的土地资源压力,对制定合适的土地管理时间策略,监测生态系统状况和态势具有重要意义.

RS-induced characteristics of land use change in Chongqing, China

Used Landsat TM and interview data, this study reconstructed spatio-temporal trajectories of land use across Chongqing, southwestern China, for the period of 1986-2005. The results indicated that during 1986-1997, cropland used for built-up land, grassland and unused land reclaimed for cropland and woodland constituted for the three largest land uses, while 1997-2005, cropland returning into woodland, used for built-up land, of conversion to water body and unused land reclaimed for cropland and woodland were main land transformation types. Built-up land expanded widely at the expense of cropland, while the amount of grassland and unused land was reclaimed for cropland again. The rapid increase of woodland derived mainly from grassland and unused land exploitation and built-up land reclamation. Underlying causes resulted in the occurrence of previous changes included policy arrangement and original patterns of land resources. The former determines the basic orientations of land use at short-term scale, while the latter are crucial forces that figure the heterogeneity of regional land use. These trends were found to be indicative of increasing pressure on available land resources, leading to extensive significant for the development of land management policies, and for the monitoring of ecosystem status and trend.