Impacts of Urban Expansion in ChongQing on Its Land Use Change Since 1978

摘要

Urban space expansion is an important indicator for measuring urbanization level. Based on one Landsat MSS image and three Landsat TM remotely sensed images, the urban built-up area characteristic of ChongQing and its impact on the peripheral land use during 1978-2005 was analyzed. The results show that Chongqing developed by leaps and bounds and experienced three major stages, i.e., relatively stable period in the 1980s, the slow development period after the mid-1980s and the relatively highspeed development period in recent years. The urban area was 8732km2 in 1978 and increased to 282.91km2 in 2005, the built-up area increased by 194.89km2 during the past 27 years and expanded 722km2 per year. The built-up area expanded around the old area and present manifest change in a certain direction. The increased built-up area originates from different land use type, of which about 2052% converted from rural area and dependent factory, diggings land and other construction area. The other mainly came from arable that accounts for 76.86% of the whole added built-up area. Many factors have contributed to the urban land use changes. But four major driving forces, population growth, economic increase, transportation infrastructure improvement and institution and policy change, are the most important factors. Population growth simulate the built-up area manifestly, the economic increase is the main impetus of the land use, and the transportation infrastructure improvement is the impetus for the urban expansion, while the institution and policy change determine the macroscopical development and expansion pattern in some degree.