Cyanobacterial flora and the physico-chemical environment of six tropical fresh water lakes of Udaipur, India

The cyanobacteria and physico-chemical environments of sic tropical fresh water lakes of Udaipur,India were investigated.These lakes receive varying nutrient inputs from different sourcesi.Altogether 51 species of cyanobacteria were recorded.Species composition varied between lakes and between seasons.Lake VI(Beghdara),which receives nutrients from natural sources only,differed considerably from the others in water chemistry and composition of dominated species.Lake Ⅱ(Swaroop Sagar),eutrophied due to sewage inputs,was species poor.Non-diazotrophs,represented by 27 species,dominated during summer.With few exceptions,N2-fixing species,bothe heterocystous and unicellular diazotrophs (represented by 24 species),were dominant during winter.Microcystis aeruginosa,Phormidium sp.and Anabaena flos-aque were ther dominant taxa of lakes characterized by sewage eutrophication.The study shows that both species diversity and community composition were affected by water chemistry.     

特别数字

505万个奥运塑料袋全部降解;2008年中国1．5万家环境违法企业被立案查处;我国绿色食品年销售额超2000亿元;全国已创建各级绿色学校4万余所;中国最大内陆淡水湖获科威特3500万美元环保贷款     

浅析我国内陆淡水湖库富营养化及防控措施

我国河湖水系众多,湖库水质直接关乎城市及农村用水安全。近40年以来随着我国工农业生产的快速发展,涉水污染也在逐步加剧,大量高营养盐来水汇入湖库,导致藻类及其他浮游生物大量繁殖,由此引发了一系列涉水环境事故,严重制约区域经济的健康发展并构成环境安全隐患。本文旨在通过对我国湖库富营养化发生发展趋势及主要防控措施的剖析,以期为湖库富营养化的针对性治理提供借鉴思路。     

洞庭湖面临罕见水危机

今年入秋以来,中国第二大淡水湖洞庭湖水位持续下降。10月下旬,洞庭湖主要控制站城陵矶水文站水位一度降至21.62米,为1960年以来罕见的低水位。目前,洞庭湖蓄水量不足8亿米^3,尽管整体水质明显改善,但水资源短缺已成为湖区面临的新难题。位于湖南省境内的洞庭湖是长江中游最重要的调蓄湖泊,湖泊面积2625千米^2,仅次于江西省的鄱阳湖。由于水位下降,湖中散布的洲滩明显抬高,露出一条条数米高的土黄色水际线。