中文摘要：

以重庆市忠县为例,构建土地利用转移矩阵模型和重心模型,采用区域生态环境质量指数、土地利用生态贡献率指数等分析了忠县土地利用时空转型特点及其重心演变规律,揭示出忠县区域生态环境变化趋势。结果表明：11990—2015年,忠县土地利用转型特征主要表现为生态用地面积显著增加,生活用地面积不断扩大,生产用地面积明显减少。21990—2015年,生态用地和农业生产用地重心在空间上变化不明显,城乡生活用地和工矿生产用地重心发生明显偏移。31990—2015年,忠县总体生态环境质量指数稍有增加,区域内生态环境改善与恶化趋势并存,生态改善趋势大于恶化趋势。

英文摘要：

This paper picked up the land use data of 1990,2000,2005,2010 and 2015 in Zhongxian to establish the transition matrix model and gravity model of land use based on the classification of land use function dominated by ＂production - ecology - living＂. Then, index of regional eco - environmental quality and ecological contribution ratio of different kinds of land changes were employed to quantitatively analyze the spatial - time transformation characteristics and evolution regulation of gravity center of land use. Consequently, the changing tendency of regional eco - environmen- tal caused by the land use transition was revealed, and the response mechanism of eco- environmental against land use type was illustrated. The re- suits showed：①From 1990 to 2015, characteristics of land use transition in Zhongxian were that ecological land and living land were increased by 89.789km2 and 58.710km2 respectively, and productive land was decreased by 148.632km2 . The land use transition in 1990 - 2000 was most intens- ively. ②The gravity centers of dominantly functional land uses showed distinctive spatial changing tendency. The gravity centers of ecological and agri- cultural lands had a little change, the gravity centers of rural land and mining land had change obviously. The rural land showed the ＂Z＂ - typed change. The mining land showd the ＂N＂ - typed change from 1990 to 2010. ③The eco- environment quality was increased slightly. The contribution ratios for environmental improvement and deterioration were 1. 30270 and 0.79506 respectively. The improvement of eco- environmental was mainly because a large fraction of agricultural land was occupied by the forest ecological land, and the contribution ratio was as high as 78.14 % . Whereas, the critical reason for the eco - environmental deterioration was that the ecological land was occupied by living and production lands to a larger extent.