洞庭湖流域中上游地区景观格局变化及其驱动力

基于GIS、RS技术，对1980—2000年洞庭湖流域中上游地区景观格局的时空变化特征进行了研究，并分析了该区景观演变的驱动因素.结果表明：1980—2000年，研究区不同景观类型间的面积变化差异较大，其中，面积变化显著的景观类型从大到小依次为有林地、山地水田和疏林地；景观面积的变化主要发生在山地区和丘陵区，且由东往西呈减少趋势，即湘水流域的景观面积变化最大，然后依次为资水流域、沅水流域和澧水流域.1980—1995年，各类景观的斑块形状大多呈现简单和规则化趋势，1995年后其复杂程度逐步增加.农村人口对自然生态系统的压力、流域发展对自然资源的依赖程度、为维持自然生态系统功能进行的投入以及农业产业政策调整是研究区景观格局变化的最主要驱动力.

Landscape pattern change and its driving forces in middle and upper reaches of Dongting Lake watershed.

Based on GIS and RS, the landscape pattern change in the middle and upper reaches of Dongting Lake watershed from 1980 to 2000 was studied, with its driving forces analyzed. The results showed that there was a remarkable difference in the area change of various landscape types, with the sequence of forest land > mountain paddy field > open forest land. This change mainly occurred in mountainous and hilly areas, and had a decreasing trend from the east to the west, i. e., decreased in the order of Xiangshui River valley > Zishui River valley > Yuanshui River valley > Lishui River valley. The patch shape was simple and regular from 1980 to 1995, but diversified from 1995 to 2000. The main driving forces of the landscape pattern change were the pressure of booming farming population on natural ecosystem, the dependence of watershed' s development on natural resources, the investment to protect and improve the functions of natural ecosystem, and the adjustment of agricultural polices.