成都东湖水体富营养化研究

Study on eutrophication of Donghu Lake in Chengdu

对水体富营养化现状进行科学研究是其后续利用、保护或治理工作的前提.本研究选取成都市中心区域唯一的原生态浅水湖泊东湖为研究对象.于2019年4月测定了该水体水温(Temp)、溶解氧(DO)、pH、总氮(TN)、总磷(TP)、高锰酸盐指数(CODMn)、叶绿素a(Chl a)等水质指标,并通过综合营养指数(TLI)和参数法(基于TP、Chl a)对其富营养化现状进行了研究.结果表明,东湖水体TN含量为0.38~0.75 mg/L,TP为0.093~0.134 mg/L,CODMn为5.85~45.72 mg/L,Chl a为6.08~67.44 mg/m3;研究建议该水体富营养化评价以TLI为主,辅以Chl a参数法;TLI法评价结果显示研究水体绝大多数点位(1~8号点)处于轻度营养化状态,子湖区域的9号点处于中度营养化状态,水动力条件差可能是子湖区域9号点在相同营养盐水平下表现出更严重富营养化程度的原因.本研究可以为东湖水体保护和开发提供数据支撑,助力城市生态文明建设.

Scientific research on eutrophication of a water body is the prerequisite for subsequent protection and governance.In this study, Donghu Lake, the only original shallow lake in the central area of Chengdu, was selected as the research object.In April 2019, temperature(Temp), dissolved oxygen(DO), pH, total nitrogen(TN), total phosphorus(TP), permanganate index(CODMn) and chlorophyll a(Chla) were monitored. Furthermore,assessment of eutrophication was conducted using comprehensive trophic index method(TLI)and single parameter method(based on TP,CODMn). The results showed that the concentration of TN, TP, CODMn and Chla ranged from 0.38 to 0.75 mg/L, 0.093-0.134 mg/L,5.85-45.72 mg/L and 6.08-67.44 mg/m3, respectively.In addition, this study suggested that the assessment of Donghu Lake eutrophication should be mainly based on TLI, supplemented by Chla parameter method.The results of TLI method showed that most sites(sites 1-8)in Donghu Lake were in a light eutrophication state, and site 9 in son lake was in a moderate eutrophication state. What is more, poor hydrodynamic conditions may cause more severe eutrophication at site 9 in son lake than that of other sites when they were under the same nutrient level.This study can provide data support for the protection and development of the Donghu Lake and help the ecological civilization construction.