基于综合营养状态指数和BP神经网络的黑河富营养化评价

Eutrophication Evaluation of Heihe River Based on Comprehensive Trophic State Index Method and BP Neural Network

[目的]探究黑河流域富营养状态,为黑河流域水体污染综合防治提供基础数据和理论依据。[方法]选取叶绿素a(Chl.a)、总氮(TN)、总磷(TP)、高锰酸盐指数(COD_(Mn_))、透明度(SD)作为评价因子,使用综合营养状态指数法和BP神经网络对黑河流域的富营养化进行综合评价。[结果]黑河富营养化状况主要以中营养级为主,其中野牛沟和张掖湿地的营养指数接近轻度富营养程度,东居延海处于重度富营养化,尤其是总氮指数很高,应该及时进行治理和保护。[结论]相对于综合营养状态指数法,BP神经网络对黑河流域的评价结果更加贴近实际结果,较为客观可靠。

[Objective] To evaluate the current eutrophication state and provide basic data and theoretical support for the pollution control in Heihe River basin.[Methods] The total nitrogen （TN）, total phosphorus （TP）, permanganate index （CODMn）, chlorophyll a （Chl.a）, transparency （SD） were selected as indexes for water quality evaluation, and the comprehensive trophic state index and BP neural network were used to evaluate the eutrophication of Heihe River basin.[Results] The eutrophication status of Heihe River basin was mainly in medium level of nutrition. The nutrition status index of Yeniugou and Zhangye wetland were close to mild eutrophication. The eutrophication status of East Juyanhai Lake was severe and the total nitrogen index was high. The water environment of East Juyanhai Lake should be protected in time.[Conclusion] Compared to the comprehensive trophic state index method, the evaluation results of BP neural network are closer to the actual situation, and more objective and reliable.