长江水系鱼类分布的模糊聚类分析

Fuzzy Cluster Analysis of the Distribution of the Fishes in Changjiang(Yangtze) River System

应用模糊聚类法对长江水系鱼类分布进行研究，结果表明，在λ＝０．７５３７时，长江水系鱼类分布可分为八类：长江上游干流、沱江、嘉陵江为一类；长江中、下游干流、湘江、赣江、洞庭湖、鄱阳湖、洪湖、梁子湖、巢湖、太湖为一类；岷江、程海、泸沽海、滇池、汉水、长江河口干流各为一类；当λ＝０．７０４９时，可分为六类：程海、泸沽海、滇池、长江河口干流各为一类，岷江与长江上游干流、沱江、嘉陵江合为一类，汉水与中下游水系合为一类。

Fuzzy cluster analysis was made to study the distribution of the fishes in Changjing River system. The results showed that the distribution may be divided into 8 types when λ equaled 0.753 7. The upper reaches of changjiang River, the Tuojiang River, the Jialing River are clusteredinto a type; the middle reaches of Changjiang River, the lower reaches of Changjiang River, the Xiangjiang River, the Ganjiang River, the Dongtin Lake, the Poyang Lake, the Honghu Lake, the Liangzhi Lake, the Caohu Lake and the Taihu Lake are clustered type, while the Minjiang River, the Chenghai Lake, the Lukuhai Lake, the Dianchi Lake, the Hanshui River and the Changjiang River mouth each forms a single type. When λ equal 0.704 9, altogether 6 types are defined, the Chenghai Lake, the Lukuhai Lake, the Dianchi Lake and the Changjiang River mouth each represents a single type, the Minjiang River, the Tuojiang River, theJialing River and the upper reaches of Changjiang River are chustered into a type, and the Hanshui River and its middle and lower system are clustered into a type.