基于不同水质评价方法的东洞庭湖区重要水库水质评价研究

Study on Water Quality Evaluation of Important Reservoirs in East Dongting Lake Area Based on Different Water Quality Evaluation Methods

摘要: 本文采用单因子指数法、均值综合污染指数法和内梅罗综合污染指数，以高锰酸盐指数、化学需氧量、五日生化需氧量、氨氮、总磷5项监测指标作为参评因子，对东洞庭湖区8个重要水库2020～2022年水质状况进行评价，结果表明：单因子指数法水质大部分为I级和II级，仅个别月份为III级，主要污染为总磷和氨氮，且2020年全年水质状况要优于2021、2022年；均值综合污染指数法水质结果均在0.18~0.69之间，水质处于“水质好”与“轻度污染”之间，I类水质占比1.6%，II类水质占比62.82%，III类水质占比35.58%；内梅罗综合污染指数法整体水质状况良好，均为I类清洁水质，且季节变化显著，秋季水质相对较差。单因子指数法可快速准确评价水质类别，均值综合污染指数法和内梅罗综合污染指数法能定量反映水质的差异，更全面地反映出水体的整体状况。在实际应用中，应结合几种评价方法，以获得更全面、准确的水质评价结果。

Abstract: This paper adopts the single-factor index method, the mean integrated pollution index method and the Nemero integrated pollution index to evaluate the water quality status of eight important reservoirs in the East Dongting Lake area from 2020 to 2022 with five monitoring indicators, including the permanganate index, chemical oxygen demand, five-day biochemical oxygen demand, ammonia nitrogen, and total phosphorus, as the reference factors. The results show that: most of the water quality of single-factor index method is Class I and Class II except individual months for Class III. The main pollution is total phosphorus and ammonia nitrogen, and the water quality of the whole year 2020 is better than that of 2021, 2022; the results of the mean value of the integrated pollution index method of the water quality are 0.18~0.69 between “good water quality” and “mild pollution”. Class I water quality accounted for 1.6% and Class II 62.82%, and Class III water quality accounted for 35.58%. Nemero integrated pollution index method of the overall water quality is good with all samples meeting Class I clean water standards. Water quality seasonal changes are significant, and the water quality in the fall is relatively poor. Water quality is between “good water quality” and “mildly polluted”; Nemero integrated pollution index method overall water quality is good, and water quality seasonal changes are significant, and water quality in the fall is relatively poor. The single-factor index method can quickly and accurately evaluate the water quality category, and the Mean Composite Index Method and the Nemero Composite Index Method can quantitatively reflect differences in water quality, providing a more comprehensive assessment of the overall condition of water bodies. In practical application, several evaluation methods should be combined to obtain more comprehensive and accurate water quality evaluation results.