长江口湿地景观镶嵌结构演变的数量特征与分形分析

鉴于国内湿地研究对象大多为块状湿地。而对狭长形湿地鲜有研究，本文利用1990年和2003年遥感影像作为基本信息源。在GIS技术支持下。选取长江口狭长湿地，建立长江口湿地植被空间数据库。选取斑块大小、分维数、景观破碎度、景观多样性和优势度等指标，研究区域景观的数量特征动态变化；运用分形理论建立各种景观类型形态的分形结构模型，以分维数为依据分析各种景观形态的复杂性；探讨控制和影响区域景观格局的主要因素。结果显示，1990—2003年期间，在自然与人为双重因素作用下该地区的湿地景观发生了显著变化，景观趋于破碎化。植物群落的演替由于人为的原因加速，一些地区景观呈自然变化趋势。一些地区由于围垦的原因。人为扰动大。呈现衰退趋势。

Quantitative and fractal characteristics of mosaic structure evolution on the wetland in the bayou of the Yangtze River

By using 1990 and 2003 remote sensing data as basic information resource and with the support of GIS, a wetland spatial information data set is built up. Through selecting the indices such as patch size, fractal dimension, fragmentation, diversity and dominance index, etc, and using quantitative methods, the dynamic development of wetland landscape pattern is analyzed. The result shows that the change of wetland landscape pattern is significant from 1990 to 2003, and the wetland and landscape pattern tends to be fragmental. The succession of plant community in wetland is accelerated artificially. The views of some areas are changing naturally. On the contrary, some areas are changing towards bad condition because of the inning and destruction of the environment by man.