基于Landsat TM的西安地区土地利用与覆被变化

Study on the Land Use/cover Change in the Xi'an Region Based on Landsat TM Images

以西安地区为研究对象,采用1988年和2000年2期遥感影像,利用改进的BP神经网络分类法,提取研究区的土地利用信息,并结合统计数据进一步分析引起变化的原因。研究表明,城镇建设用地通过侵占大量农田而得到迅速扩张,共有43 565 hm2农田被开发为建设用地;农田与水域面积大量减少,果园面积有较大增加,增幅为187.3%;国家政策的调控是造成这种变化的宏观驱动力。铁路和公路等交通干线的发展是城镇建设用地迅猛发展的直接动力。人口的增长和第一产业的迅速发展是造成耕地面积大量减少的直接原因。果园面积的增加主要是由于第一产业的发展。

The Xi＇an region （33°39′ -34°45′N, 107°40′- 109°49′E） is located in the central Guanzhong Basin in northwest China, and its area is 998 300 hm^2. The landforms include mainly the piedmont diluvial mesas, Qinling Mountains and valley-alluvial plains. The annual temperature and the maximum and minimum monthly temperatures are 13.3 ℃, 26.6 ℃ and 0.4 ℃ respectively, the annual precipitation is 613.7 mm, and the average annual humidity is 69.6 %. In this paper, the land use/cover change （LUICC） in the Xi＇ an region is researched using two sets of Landsat images acquired in 1988 and 2000, the land use information in the study area is derived with the improved BP NN classification, and the causes resulting in LUCC are analyzed. The results show that the area of urban and rural building lands is sharply expanded by reducing the area of farmlands, and the farmlands of 43 565 hm^2 in area are used as the building lands; the areas of farmlands and waters are sharply reduced, but the area of orchards is enlarged by 187.3% ; the macroscopical driving force and the direct driving force of LUCC are the regulation and control of state policies and the sharp expansion of traffic lines and urban and rural building lands respectively; the sharp reduction of the area of farmlands is directly caused by sharp population growth and rapid development of primary industry, and enlargement of the area of orchards is mainly brought about by the development of primary industry.