基于东鱼河摇蚊群落的水环境质量评价

评价;冗余分析;水环境质量;东鱼河

中图分类号：X82 文献标志码：A

Abstract：As the longest river discharging into the Nansi Lake，the Dongyu River plays an important role on the water quality of the Nansi Lake.To better understand the relationship between the community structure of chironomid and eutrophication of the Dongyu River，the head shells of larvae preserved in the upper 2-cm-thick loose bottom sediments were investigated with eight samples collected in May 2013.A total of 30 Chironomus species were identified in the Dongyu River surface sediments.The main genus were composed of Glyptotendipes pallens-type （20.42%），Cricotopus sylvestris-type （18.23%），Chironomus plumosus-type （15.24%），Tanytarsus mendax-type （7.35%），Dicrotendipes nervosus-type （7.12%），Chironomus anthracinus-type （6.23%），and Polypedilum nubifer-type （5.38%），accounting for 79.97% of the total counts.Based on the biodiversity index and principal component of the Dongyu River，the water body was in a mild to moderate pollution level.Redundancy analysis showed that NH3-N was the main water environmental factor resulting in the distribution of the chironomid in the Dongyu River，and the responses of different species of Chironomid to NH3-N were varied. It can also be inferred that the Dongyu River is a medium-eutrophic river，according to the ecological characteristics of the chironomid combination，with serious pollution in the middle and lower reaches，which are the key areas for water pollution control.

Key words：Chironomidea;biological evaluation;redundancy analysis;water quality;Dongyu River

南四湖是南水北調东线重要的调蓄湖泊，东鱼河作为南四湖最大的入湖河流，其水质状况不仅关系到河流沿线居民的生产生活和经济发展，同时也关系到到南水北调东线输水工程的水质安全[1-2]，对入南四湖河口水质有着重要影响。东鱼河作为一条人工河，桥、涵、闸建筑物108座，河流受人工控制较强，东鱼河水质主要受到沿岸居民生产生活影响。武周虎等[3]就2010-2011年期间的南四湖的35个入湖河口水质监测数据分析其等标污染物负荷，东鱼河负荷比为7.0%，是南四湖10条主要排污河流之一，也成为南四湖治污的重点。东鱼河作为国家水资源监控能力建立淮河流域二期项目之南四湖19条入湖河流水量监控站点之一[4]，其流域范围内自然条件恶劣，降水量小于蒸发量，更增大了污染物扩散及转化的阻力，加剧水质安全的威胁。近些年在人类活动的干扰下，水质状况越来越差，径流量逐渐降低[5]，随着当地城镇化进程加快、城镇人口数量增加，城市生产生活用水量大幅度增加，加快东鱼河水环境治理具有现实意义。