After water storage in the Three Gorges Reservoir Region,there are no outbreaks of algal blooms in the main stream of the reservoir region,but the density of algae increases obviously. Outbreaks of algal blooms mainly...After water storage in the Three Gorges Reservoir Region,there are no outbreaks of algal blooms in the main stream of the reservoir region,but the density of algae increases obviously. Outbreaks of algal blooms mainly appeared in the tributaries of the reservoir region such as the Xiangxi River,Daning River,Shennong River and Xiaojiang River,but they did not occur every year. The reasons for outbreaks of algal blooms in the tributaries are shown as follows: the existence of sources of algae(blue-green algae) in the Three Gorges Reservoir is the root cause,and the sources include sources existing and being produced in the reservoir and sources from upstream main stream and its tributaries and other related lakes and reservoirs,of which the sources are mainly from the Dianchi Lake; slight or moderate eutrophication of water is the basic condition;hydrologic and hydrodynamic conditions and suitable temperature are conducive to proliferation and aggregation of algae(blue-green algae) after the operation of the Three Gorges Reservoir until outbreaks of algal blooms appear. Outbreaks of algal blooms in the tributaries of the Three Gorges Reservoir Region mainly appear in backwater reaches; they mainly occur in the tributaries in the north of the reservoir region and near to the dam;they mainly appear from March to July; the dominant species of algae( blue-green algae) in the Three Gorges Reservoir are Pyrrophyta,Bacillariophyta and Chlorophyta,but they tend to change into blue-green algae and other algae. To control outbreaks of algal blooms in the tributaries of the Three Gorges Reservoir Region,it is needed to prevent water containing blue-green algae collected from the Dianchi Lake and other lakes and reservoirs from being input into the lower reaches,reduce pollution load flowing into the Three Gorges Reservoir,use enclosures to change hydrodynamic conditions of backwater reaches of the tributaries appropriately,and adopt biological measures such as culturing fish and planting plants to improve ecosystem of the tributaries and other measures to inhibit and eliminate algae and decrease eutrophication level.展开更多
2006年3、5、8月,对三峡水库成库后5条支流的上游区和回水区水质参数及营养因子分布进行了初步研究.研究结果表明,支流高锰酸盐指数范围在1.00-2.50mg/L、COD范围为6.00-26.5mg/L,上游区与回水区有机物含量差异不大,支流目前未受到有机...2006年3、5、8月,对三峡水库成库后5条支流的上游区和回水区水质参数及营养因子分布进行了初步研究.研究结果表明,支流高锰酸盐指数范围在1.00-2.50mg/L、COD范围为6.00-26.5mg/L,上游区与回水区有机物含量差异不大,支流目前未受到有机物污染影响.NH_4^+-N范围为0.039-0.367mg/L,各支流含量均为丰水期最大.TN范围在0.58-1.67mg/L,TP范围在0.005-0.133mg/L,支流回水区TN和TP含量均远高于水体发生富营养化的最低限制值,水体存在发生富营养化的风险.大多支流N/P比值处于适宜藻类生长范围.Chl.a浓度范围为0.94-28.9mg/m^3,各支流回水区Chl.a浓度均为5月最大河流回水区Chl.a浓度高于上游区,上游区、回水区Chl.a含量有显著差异.选用修正的Carlson营养状态指数(Trophic State Index)TSI_M法,评价了支流水体营养状态,TSI_M指数范围在36.0-64.2,上游区除龙河、澎溪河5月达到富营养水平外,其余支流均为贫-中营养水平.回水区各支流均达到中-富营养水平.支流回水区营养状态指数均高于上游区,但各支流增加幅度不同.支流回水区水体营养状态明显受三峡水库蓄水水体流速减缓的影响.Chl.a与COD(n=15,P<0.01)呈极显著正相关,与其它营养因子无明显相关关系.三峡水库完工后,支流回水区水体流速减缓,富营养化趋势可能加重.展开更多
为揭示三峡支流细菌群落的多样性和分布特征,采用高通量16s r DNA测序技术,于2014年5月对大宁河和香溪河细菌进行调查研究,同时检测水环境因子。结果表明,大宁河和香溪河细菌种类丰富,共检出细菌和古生菌25门,其中比例最高的为变形菌门,...为揭示三峡支流细菌群落的多样性和分布特征,采用高通量16s r DNA测序技术,于2014年5月对大宁河和香溪河细菌进行调查研究,同时检测水环境因子。结果表明,大宁河和香溪河细菌种类丰富,共检出细菌和古生菌25门,其中比例最高的为变形菌门,占69.01%,放线菌门其次,占11.46%。变形菌门中,γ-变形菌最多,占该门类总数的35.22%,β-变形菌其次,为22.18%。细菌多样性指数Shannon指数平均为13.2,Simpson指数接近于0,Chao1指数平均为48 633 611.4,可见三峡支流的细菌种类极其多样。几种丰度较高的细菌在空间上具有不同的分布特征。统计分析显示对细菌组成与分布影响最显著的因子为总无机碳,其次是总有机碳、叶绿素,其它因子影响较小。放线菌、γ-变形菌、δ-变形菌和浮霉菌与总有机碳正相关。叶绿体纲细菌和叶绿素含量存在正相关,而变形菌、梭菌纲细菌则与其负相关。变形菌与氮磷和总碳成较强的正相关,所以碳源的增加使变形菌丰度提高。营养水平是影响细菌群落结构的重要因素之一。营养水平越高,α-变形菌比例越高。营养水平低则δ-变形菌比例上升。支流上不同河段的环境因子有明显的空间分布的差异(P<0.05)。这些差异造成了大宁河和香溪河细菌群落结构的空间异质性。展开更多
文摘After water storage in the Three Gorges Reservoir Region,there are no outbreaks of algal blooms in the main stream of the reservoir region,but the density of algae increases obviously. Outbreaks of algal blooms mainly appeared in the tributaries of the reservoir region such as the Xiangxi River,Daning River,Shennong River and Xiaojiang River,but they did not occur every year. The reasons for outbreaks of algal blooms in the tributaries are shown as follows: the existence of sources of algae(blue-green algae) in the Three Gorges Reservoir is the root cause,and the sources include sources existing and being produced in the reservoir and sources from upstream main stream and its tributaries and other related lakes and reservoirs,of which the sources are mainly from the Dianchi Lake; slight or moderate eutrophication of water is the basic condition;hydrologic and hydrodynamic conditions and suitable temperature are conducive to proliferation and aggregation of algae(blue-green algae) after the operation of the Three Gorges Reservoir until outbreaks of algal blooms appear. Outbreaks of algal blooms in the tributaries of the Three Gorges Reservoir Region mainly appear in backwater reaches; they mainly occur in the tributaries in the north of the reservoir region and near to the dam;they mainly appear from March to July; the dominant species of algae( blue-green algae) in the Three Gorges Reservoir are Pyrrophyta,Bacillariophyta and Chlorophyta,but they tend to change into blue-green algae and other algae. To control outbreaks of algal blooms in the tributaries of the Three Gorges Reservoir Region,it is needed to prevent water containing blue-green algae collected from the Dianchi Lake and other lakes and reservoirs from being input into the lower reaches,reduce pollution load flowing into the Three Gorges Reservoir,use enclosures to change hydrodynamic conditions of backwater reaches of the tributaries appropriately,and adopt biological measures such as culturing fish and planting plants to improve ecosystem of the tributaries and other measures to inhibit and eliminate algae and decrease eutrophication level.
文摘2006年3、5、8月,对三峡水库成库后5条支流的上游区和回水区水质参数及营养因子分布进行了初步研究.研究结果表明,支流高锰酸盐指数范围在1.00-2.50mg/L、COD范围为6.00-26.5mg/L,上游区与回水区有机物含量差异不大,支流目前未受到有机物污染影响.NH_4^+-N范围为0.039-0.367mg/L,各支流含量均为丰水期最大.TN范围在0.58-1.67mg/L,TP范围在0.005-0.133mg/L,支流回水区TN和TP含量均远高于水体发生富营养化的最低限制值,水体存在发生富营养化的风险.大多支流N/P比值处于适宜藻类生长范围.Chl.a浓度范围为0.94-28.9mg/m^3,各支流回水区Chl.a浓度均为5月最大河流回水区Chl.a浓度高于上游区,上游区、回水区Chl.a含量有显著差异.选用修正的Carlson营养状态指数(Trophic State Index)TSI_M法,评价了支流水体营养状态,TSI_M指数范围在36.0-64.2,上游区除龙河、澎溪河5月达到富营养水平外,其余支流均为贫-中营养水平.回水区各支流均达到中-富营养水平.支流回水区营养状态指数均高于上游区,但各支流增加幅度不同.支流回水区水体营养状态明显受三峡水库蓄水水体流速减缓的影响.Chl.a与COD(n=15,P<0.01)呈极显著正相关,与其它营养因子无明显相关关系.三峡水库完工后,支流回水区水体流速减缓,富营养化趋势可能加重.
文摘为揭示三峡支流细菌群落的多样性和分布特征,采用高通量16s r DNA测序技术,于2014年5月对大宁河和香溪河细菌进行调查研究,同时检测水环境因子。结果表明,大宁河和香溪河细菌种类丰富,共检出细菌和古生菌25门,其中比例最高的为变形菌门,占69.01%,放线菌门其次,占11.46%。变形菌门中,γ-变形菌最多,占该门类总数的35.22%,β-变形菌其次,为22.18%。细菌多样性指数Shannon指数平均为13.2,Simpson指数接近于0,Chao1指数平均为48 633 611.4,可见三峡支流的细菌种类极其多样。几种丰度较高的细菌在空间上具有不同的分布特征。统计分析显示对细菌组成与分布影响最显著的因子为总无机碳,其次是总有机碳、叶绿素,其它因子影响较小。放线菌、γ-变形菌、δ-变形菌和浮霉菌与总有机碳正相关。叶绿体纲细菌和叶绿素含量存在正相关,而变形菌、梭菌纲细菌则与其负相关。变形菌与氮磷和总碳成较强的正相关,所以碳源的增加使变形菌丰度提高。营养水平是影响细菌群落结构的重要因素之一。营养水平越高,α-变形菌比例越高。营养水平低则δ-变形菌比例上升。支流上不同河段的环境因子有明显的空间分布的差异(P<0.05)。这些差异造成了大宁河和香溪河细菌群落结构的空间异质性。
