平原河网水体富营养化评价
Eutrophication Evaluation of Water in the Plain River Network

根据实用性和适用性原则，选择对数型幂函数普适指数公式，分析和评价平原河网地区水体的富营养化状态。选取溶解氧、叶绿素a、总磷、总氮、高锰酸盐指数、氨氮、硝酸盐氮七项指标作为富营养化的评价因子。设定各指标的“极贫”营养值作为“参照值”，通过“规范转换式”将所有水质指标实测值转换成“规范值”，利用对数型幂函数普适指数公式将“规范值”综合计算成营养状态综合指数，对水体富营养化状态进行评价。结果表明：对数型幂函数普适指数公式适合于评价平原河网水体的富营养化状态；平原河网水体普遍处于富营养甚至重富营养状态，其富营养状况与季节存在关联性；氮和磷是影响水体富营养化状态的主要因素，磷的影响最大。
According to the principle of practicality and applicability, the universal exponential formula of loga-rithmic power function is chosen to analyze and evaluate the eutrophication status of water in the plain river network area. Seven indicators, namely dissolved oxygen, chlorophyll a, total phosphorus, total nitrogen, permanganate index, ammonia nitrogen and nitrate nitrogen, were selected as evaluation factors for eutrophication evaluation. After setting “very poor” nutritional values for each indicator as “reference values”, all water quality indicators measured values are converted into “normative values” by “normative values conversion formula”. The “normative values” are integrated into a comprehensive index of nutrient status using the universal exponential formula of logarithmic power function to evaluate the eutrophication status of water bodies. The results show that the universal exponential formula of logarithmic power function is suitable for evaluating the eutrophication status of water in the plain river network. The plain river network water is generally in eutrophic or even heavy eutrophic state, and their eutrophic status is correlated with seasons. Nitrogen and phosphorus are the main factors affecting the eutrophication status of water, while phosphorus has the greatest influence.