贵州省大坝土地利用变化及驱动力分析

ANALYSIS OF LAND USE CHANGE AND DRIVING FORCE IN GUIZHOU

选取贵州省万亩（1亩=1／15hm2）以上的坝子为研究对象，以GIS为技术支撑，通过空间叠加分析，提取研究区10a来的土地利用／覆被信息，并结合相应的社会经济统计数据，进一步分析引起变化的驱动力影响因子。结果表明：（1）2000～2005年、2005～2010年两个时段，耕地面积一直在持续减少，第二时段的变化比第一时段更剧烈；林地、城镇建设用地、农村居民点、水域、道路在两个时段都不同程度的增加，其中城镇建设用地、农村居民点在第二时段比第一时段增加的速度更快，其它3种地类增加的速度有所减缓；灌木总体变化是出现先减后增的趋势；（2）耕地在2000~2005年的流向主要是林地，在2005-2010年流向主要是居民点和城镇建设用地；（3）研究区土地利用变化受人口、经济效益、政策的影响。

Understanding land use change and associated driving forces is fundamental for optimizing land use and providing scientific basis for sustainable utilization of land resources. We selected the basins that are larger than 10 000-mu in Guizhou Province in the present study. Using GIS techniques and spatial analysis,land use/over information of recent 10 years was extracted and the cause of changes was further studied. With support of socioeconomic data,the results showed that the area of cultivated land continually reduced and the second study period （i. e. ,2005--2010） was severer than the first （i. e. ,2005--2010）. The decreased cultivated lands were 7 874. 73 hm2 and 10 521.73 hm2, showing an continuous reducing trend. In the two temporal phases, forested lands, urban construction lands, rural residential areas, water, and roads increased in different degrees. Meanwhile, urban construction lands and rural residential areas in the second temporal phase increased much faster than the first one, while the other three type of lands increased more slowly. Shrublands were firstly decreased and then increased. Cultivated lands were mainly turned to woodlands from 2000 to 2005,and mainly to rural residential areas and urban construction lands from 2005 to 2010. The variation of cultivated land was the major characteristic of land use change in the study area. There are two possible driving forces of these land changes. The first one was state policy （such as the urbanization promotion and new rural construction）. The second one was increasing mining and traffic flow. Using principal component analysis, we classified and standardized 10 factors. The results showed that land use change in study area was affected by population, economic benefits and policy. An increasing population led to urban construction and increasing rural residential areas. Land use intensity should be enhanced to meet the increasing population and the rising consumption demand. Policy also had an impact on the land use.