摘要
所谓水团分析，主要是指划分水团的边界，确定水团的基本特征以及分析研究水团的消长变化规律。本文研究的海区大多属于浅海区域。浅海水团易受海洋外部因素的影响，变性显著，因此，浅海水团的分析实际就是水团的变性分析。所谓水团的变性，主要是指水团特征的示性水平从高向低的过渡，并逐渐丧失其示性特征的这一过程。
Based on the idea of modified water masses, a cluster analysis is used for determining the boundary of modified water masses in the sea area near the Yangtze River Mouth and Jizhou Island. The results obtained by the cluster method show that there are ten water masses in this area. A preliminary analysis, for their characteristics, distributions and variances has been made.Through the anaglysis for them, the conclusions are as follows. First,there are four oceanic and six modified water masses in ten water masses. Secondly, the characteristics of modification of water masses in this area are the increase of temperature and the decrease of salinity and oxygen in warm season and the reversal of them in cold season. Thirdly,the causes of modification of water masses result from the combinative actions of internal and external factors in the sea and the latter plays a major part in shallow sea area. Fourthly, the correlations between the tonguelike distribution of the boundary of water masses and the current direction are apparent, therefore, the current direction and strength may largely be judged by the tonguelike distribution of water masses. Lastly,the central fishing grounds at bottom layer largely lie in the mixed regions among modified water masses or the near area of them.
