三峡水库建设期秭归县土地利用时空变化特征分析

为了更好地把握水库建设期三峡库首地区土地资源变化情况，以秭归县为试验区，利用1992、2002、2007年多源多时相融合高分辨率遥感数据获取3个时期1：50 000土地利用分类结果，分析土地利用动态变化。由于三峡工程建设带来的众多非自然因素作用，秭归县土地利用类型变化剧烈，1992－2007年间园地面积比原来增加248.14%，旱地面积减少20.32%，乔木林减少0.59%，草地减少8.04%，人工表面面积增加141.84%，水体面积增加90.86%；园地、旱地、人工表面、水体等地类在1992－2002年和2002－2007年2个时期表现出不同的变化趋势。使用转换矩阵分析地物类型转换背后的驱动因素作用；根据动态度、土地利用程度等指数的计算结果，不同时期土地利用变化特征具有明显差异；把握土地利用动态演替规律，为后期水库管理运行提供建议。

Spatial-temporal changes of land use and its characteristics in Zigui County under the period of TG dam project

In order to find the detailed changes of land resources during the TG Dam project in areas of the head part of the Three Gorges reservoir, based on TM and SPOT data, this study acquired 1:50 000 land use classification results in 1992, 2002 and 2007 in Zigui County, analyzed land use dynamic changes during these different periods. Geographic Information System (GIS) techniques and land use dynamics methods were utilized to depict the characteristics of land use changes. The results of land use changes mainly indicated that garden area increased about 248.14%, dry land area decreased about 20.32%, forest area decreased about 0.59%, grass area decreased about 8.04%, urban and built-up area increased about 141.84%, water area increased about 90.86% during 1992-2007 mainly due to many influential factors of human activities brought by the Three Gorges dam project. The study also analyzed driving forces with conversion matrix in order to seize the mechanism behind land use changes. There were different trends and change velocities in changes of garden, dry land, man-made area and water area during 1992-2002 and 2002-2007 according to the dynamic indices. The characteristics of land use conversion differed greatly in these two periods by land use extent indices. Compared with land use extent results during 2002-2007, human activities had more impacts on land use changes during 1992-2002 mainly because of immigration project, cities and towns relocation and reservoir inundation. It was necessary to provide countermeasures and suggestions further to support the reservoir management in future in Zigui County.