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对长江上游12条主要河流鱼类种类数与流域特征进行了回归分析和主成分分析.相关回归分析结果显示:特有种类数目与全部种类数目呈极显著正相关;全部种类数目的绝对数与流域面积、干流长度、流量呈显著或极显著正相关,与比降呈显著负相关;单位流域面积(或单位干流长度)全部种类数与干流长度(或流域面积)、流量呈显著或极显著的负相关,与比降、径流深呈极显著正相关;特有种类数目的绝对数与流域面积、干流长度、流量呈显著或极显著正相关;单位流域面积特有种类数与干流长度、流量呈显著或极显著负相关,与比降、径流深呈极显著正相关;单位干流长度特有种类数与流域面积呈显著负相关,与比降、径流深呈极显著正相关.主成分分析得到的第一和第二主成分分别综合反映了河流鱼类的相对种类数和绝对种类数与流域特征因子之间的关系.
The regression analysis and principal component analysis of the number of fish species and the basin features of 12 major rivers in the upper reaches of the Yangtze River showed that there was a significant positive correlation between the number of endemic species and the total number of species and the absolute numbers of all species and watershed Area, main stream length and flow rate were significantly or very significantly positively correlated and negatively correlated with the specific ratio. The total number of species and main stream length (or catchment area) per unit drainage area (or unit length) was significant or extremely significant There was a significant and significant positive correlation between the absolute number of endemic species and the catchment area, the length and the flow of the main stream. The number of endemic species per area and the length of the main stream and the flow rate were significant Or very significant negative correlation, and the ratio of drop, runoff depth was extremely significant positive correlation; unit length of the number of unique species and the basin area was negatively correlated, and the ratio of drop, runoff depth was extremely significant positive correlation.Primary component analysis of the The first principal component and the second principal component respectively reflect the relationship between the relative number of species and the absolute species number of river fish and the characteristic factors of the river basin.