中国河口地球化学研究的若干进展

SOME PROGRESSES IN ESTUARINE GEOCHEMICAL STUDIES OF CHINA

在过去10年的河口地球化学研究的基础上，总结了中国一些大的河口（黄河、长江、大辽河、滦河、珠江、九龙江、闽江等）体系中的化学要素的行为特点。与世界上的大河流相比，中国河流中具有较高的营养元素和较低的痕量元素浓度。流域盆地的风化作用指数由北向南逐渐增加，这与世界上其它地区十分相似。在河口淡-咸水混合过程中，颗粒态的化学要素多呈稳定态分布模式，这与高的泥沙量、较轻的污染程度和水文动力作用相对较弱有关，并且对生态系统有显著的影响。考虑到化学要素在中国河口的行为特点，特别是中国作为一个农业国家，与耕作相关的化肥、农药的使用对河口和近岸的生产力与经济活动（例如养殖与捕捞）将会有愈来愈显著的影响，为此，在今后的工作中应将注意力更多地放到营养要素上。

Based on the geochemical studies in last decade, the present work summarizes elemental geochemistry of major Chinese estuaries including the Rivers of Huanghe,Changjiang, Daliaohe, Luanhe,Haihe, Qiantangjiang, Zhujiang, Jiulongjiang and Min-jiang etc. Comparison with other world systems reveals that Chinese rivers have low trace metal, but high nutrient elements concentrations. Also, the weathering indices which is a ratio of the stable to active elements, increases from the north to south,indicating the control of weathering on river chemistry. In the estuary, particulate elements may have a stable distribution model upon the mixing of the fresh water with sea waters, corresponding to the high turbidity, unsignificant pollution and relativelyweak dynamic conditions, in comparison to the European and North American estua-ries with macrotidal and heavy pollution effects. Elements in dissolved phase inclu-ding trace metals and nutrients may have either conservative or active distributions or both depending upon the water stage and element, and have important influences on coastal eco-systems. Considering the pattern of elemental geochemistry in Chinese estuaries, one should pay more attention to nutrient elements. Use of chemical fer-tilizers and pesticides will have significant impact on the bioproductions and econo-mic activities (e.g. marine culture) along with the advances of nation-wide indus-trialization in the near future.