喀什河流域重要渔业水域环境质量评估

Environmental quality assessment of important fishery waters in Kashi River Basin

为评估喀什河流域重要渔业水域环境质量,2023年4月~11月对伊犁河三大支流之一的喀什河水质展开了调查,测定了pH值、悬浮物、叶绿素a(Chla)、亚硝酸盐氮(NO_(2)^(-)-N)、硝酸盐氮(NO_(3)^(-)-N)、氨氮(NH_(4)^(+)-N)、高锰酸盐指数(CODMn)、总氮(TN)、总磷(TP)、溶解氧(DO)、水温T、溶解性磷酸盐(PO_(4)^(3-))、硫化物(S^(2-))共计13个指标。研究该流域水质现状和污染特征,采用综合营养状态指数对营养状况进行评价。结果显示,喀什河流域水质呈弱碱性,pH均值在7.24~8.64;全年DO变化较大,变化范围为4.18 mg/L~12.39 mg/L。各采样点间CODMn含量无显著性差异(P>0.05),变化范围为0.6 mg/L~2.1 mg/L。营养盐中TN含量在不同时间和不同采样点之间均存在显著性差异(P<0.05),养殖区TN含量与对照区相比有所增加,远离养殖区后TN含量逐渐降低。网箱养殖区叶绿素a(Chla)含量略高于对照区。各采样点综合营养指数为15.71~22.87,综合评判水体处于贫营养状态。评估结果可为新疆宜渔水域渔业资源开发利用提供数据积累和技术支撑。

In order to assess the environmental quality of important fishery waters in the Kashi River Basin,the water quality of Kashi River,one of the three tributaries of the Ili River,was investigated from April to November 2023.The pH value,suspended matter,chlorophyll a(Chla),nitrite nitrogen(NO_(2)^(-)-N),nitrate nitrogen(NO_(3)^(-)-N),ammonia nitrogen(NH_(4)^(+)-N),permanganate index(CODMn)were determined,total nitrogen(TN),total phosphorus(TP),dissolved oxygen(DO),water temperature T,dissolved phosphate(PO_(4)^(3-)),sulfide(S^(2-))a total of 13 indicators.The water quality and pollution characteristics of the basin were studied,and the nutritional status was evaluated by comprehensive nutritional status index.The results show that the water quality of Kashi River basin is weakly alkaline,the average pH value is 7.24~8.64,and the DO varies greatly throughout the year,ranging from 4.18 mg/L to 12.39 mg/L.There was no significant difference in CODMn content among all sampling points(P>0.05),and the variation range was 0.6 mg/L~2.1 mg/L.TN content in nutrient salts had significant differences at different time and sampling points(P<0.05),TN content in culture area increased compared with control area,and TN content gradually decreased after leaving culture area.The content of chlorophyll a(Chla)in cage culture area was slightly higher than that in control area.The comprehensive nutrition index of each sampling point was 15.71~22.87,and the water body was in the state of poor nutrition.The evaluation results can provide data accumulation and technical support for the development and utilization of fishery resources in Xinjiang’s suitable fishing waters.