As a result of intensifying human activities around the Changshou Reservoir, water environmental quality has declined over the years. Water quality had been monitored from 1999 to 2002. The result indicated that the c...As a result of intensifying human activities around the Changshou Reservoir, water environmental quality has declined over the years. Water quality had been monitored from 1999 to 2002. The result indicated that the concentrations of total nitrogen (TN) and total phosphorus (TP) are high. The concentrations of phosphorus range from {0.037} mg/L to {0.444} mg/L, exceeding the critical value ({0.02} mg/L) for eutrophication. The concentrations of total nitrogen and chlorophyll a range from {0.70} mg/L to {4.18} mg/L and from {1.10} mg/m3 to {61.2} mg/m3, respectively. The eutrophication status of the water body was assessed using the method of integrated nutrition state index, which revealed that all sampling sites were eutrophicated from the year of 2001. About {69.6%} of the annual total nitrogen input and 26% of the annual total phosphorus input originated from the upstreams. The contributions of nitrogen and phosphorus from precipitation to the water body are very small ({0.9%} and {0.3%}, respectively) owing to their low contents ({1.21} mg/L and {0.029} mg/L, respectively). Runoff is the secondarily important input source, which accounts for {19.0%} of the total N input and {47.0%} of the total P input, respectively. Attention should be paid to the aquaculture inputs, whose contributions account for {10.5%} of the total N and {26.6%} of the total phosphorus to the water body, respectively. Nutrient loads are estimated to be 118 gNm{-2}·a{-1} and 8 gPm{-2}·a{-1}. About {69.4%} of nitrogen and {79.7%} of phosphorus input into the reservoir were retained in 2002.展开更多
溶解性有机质（DOM）是湖泊生态系统重要组成部分,其性质和结构决定了其在污染物（例如汞）环境行为中扮演着重要角色。本研究选取三峡库区内陆腹地典型水库型湖泊———长寿湖,采用吸收光谱表征方法,通过1年时间对 DOM 地球化学变化规...溶解性有机质（DOM）是湖泊生态系统重要组成部分,其性质和结构决定了其在污染物（例如汞）环境行为中扮演着重要角色。本研究选取三峡库区内陆腹地典型水库型湖泊———长寿湖,采用吸收光谱表征方法,通过1年时间对 DOM 地球化学变化规律进行了定性定量分析,并结合汞观测数据,讨论了 DOM 对不同形态汞浓度的影响。结果表明,和1月相比,长寿湖4～11月 DOC 差异性低于 CDOM,4～11月间差异性不显著。有色组分变化是解释 DOM 季节性变化的重要原因。 DOM 中主要生色团仍然来自于大分子量的芳香性组分。而 CDOM 三波长模型可较好对 DOC 的年际观测进行反演。同时,SUVA254和S 275～295季节性变化特征较明显,1月芳香性和分子量均最小,4月上升。与其他类型湖泊相比,长寿湖水体 DOM 芳香性和分子量大小均低于森林湖泊,但高于高原湖泊。周边生态系统和土地利用类型对湖泊 DOM 差异影响明显。另外,SUVA254和 DOC与各形态 Hg 无明显相关性,但水体生色组分和分子量大小是控制溶解态和活性汞的重要因素；而湖区甲基汞变化可能与湖泊初级生产力导致的有机质富集和迁移关系密切。展开更多
文摘As a result of intensifying human activities around the Changshou Reservoir, water environmental quality has declined over the years. Water quality had been monitored from 1999 to 2002. The result indicated that the concentrations of total nitrogen (TN) and total phosphorus (TP) are high. The concentrations of phosphorus range from {0.037} mg/L to {0.444} mg/L, exceeding the critical value ({0.02} mg/L) for eutrophication. The concentrations of total nitrogen and chlorophyll a range from {0.70} mg/L to {4.18} mg/L and from {1.10} mg/m3 to {61.2} mg/m3, respectively. The eutrophication status of the water body was assessed using the method of integrated nutrition state index, which revealed that all sampling sites were eutrophicated from the year of 2001. About {69.6%} of the annual total nitrogen input and 26% of the annual total phosphorus input originated from the upstreams. The contributions of nitrogen and phosphorus from precipitation to the water body are very small ({0.9%} and {0.3%}, respectively) owing to their low contents ({1.21} mg/L and {0.029} mg/L, respectively). Runoff is the secondarily important input source, which accounts for {19.0%} of the total N input and {47.0%} of the total P input, respectively. Attention should be paid to the aquaculture inputs, whose contributions account for {10.5%} of the total N and {26.6%} of the total phosphorus to the water body, respectively. Nutrient loads are estimated to be 118 gNm{-2}·a{-1} and 8 gPm{-2}·a{-1}. About {69.4%} of nitrogen and {79.7%} of phosphorus input into the reservoir were retained in 2002.
文摘溶解性有机质（DOM）是湖泊生态系统重要组成部分,其性质和结构决定了其在污染物（例如汞）环境行为中扮演着重要角色。本研究选取三峡库区内陆腹地典型水库型湖泊———长寿湖,采用吸收光谱表征方法,通过1年时间对 DOM 地球化学变化规律进行了定性定量分析,并结合汞观测数据,讨论了 DOM 对不同形态汞浓度的影响。结果表明,和1月相比,长寿湖4～11月 DOC 差异性低于 CDOM,4～11月间差异性不显著。有色组分变化是解释 DOM 季节性变化的重要原因。 DOM 中主要生色团仍然来自于大分子量的芳香性组分。而 CDOM 三波长模型可较好对 DOC 的年际观测进行反演。同时,SUVA254和S 275～295季节性变化特征较明显,1月芳香性和分子量均最小,4月上升。与其他类型湖泊相比,长寿湖水体 DOM 芳香性和分子量大小均低于森林湖泊,但高于高原湖泊。周边生态系统和土地利用类型对湖泊 DOM 差异影响明显。另外,SUVA254和 DOC与各形态 Hg 无明显相关性,但水体生色组分和分子量大小是控制溶解态和活性汞的重要因素；而湖区甲基汞变化可能与湖泊初级生产力导致的有机质富集和迁移关系密切。
