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采用综合营养状态指数法以及时间序列分析法、箱线图、Pearson相关分析等统计分析方法对长荡湖近15年的氮、磷、Chl a等监测数据进行分析,研究长荡湖的水质现状、营养物时空分布和变化规律及藻类生物量与氮磷营养盐的关系.结果表明:自2001年以来长荡湖富营养化呈加剧趋势,近15年来的透明度呈现下降趋势,Chl a浓度则以每年5.5μg/L的速率不断攀升,长荡湖随时都可能爆发大规模的蓝藻水华;长荡湖东部出水口(北干河口区)的水质好于湖体区(湖北区、湖南区、湖心区);TP为长荡湖浮游藻类生长的限制因子. 相似文献
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Three-dimensional hydrodynamic and water quality model for TMDL development of Lake Fuxian, China 总被引:3,自引:0,他引:3
Lei Zhao Xiaoling Zhang Yong Liu Bin He Xiang Zhu Rui Zou Yuanguan Zhu 《环境科学学报(英文版)》2012,24(8):1355-1363
Lake Fuxian is the largest deep freshwater lake in China. Although its average water quality meets Class I of the China National Water Quality Standard (CNWQS), i.e., GB3838-2002, monitoring data indicate that the water quality approaches the Class II threshold in some areas. Thus it is urgent to reduce the watershed load through the total maximum daily load (TMDL) program. A three-dimensional hydrodynamic and water quality model was developed for Lake Fuxian, simulating flow circulation and pollutant fate and transport. The model development process consists of several steps, including grid generation, initial and boundary condition configurations, and model calibration processes. The model accurately reproduced the observed water surface elevation, spatiotemporal variations in temperature, and total nitrogen (TN), total phosphorus (TP), and chemical oxygen demand (COD) concentrations, suggesting a reasonable numerical representation of the prototype system for further TMDL analyses. The TMDL was calculated using two interpretations of the water quality standards for Class I of the CNWQS based on the maximum instantaneous surface and annual average surface water concentrations. Analysis of the first scenario indicated that the TN, TP and COD loads should be reduced by 66%, 68% and 57%, respectively. Water quality was the highest priority; however, local economic development and cost feasibility for load reduction can pose significant issues. In the second interpretation, the model results showed that, under the existing conditions, the average water quality meets the Class I standard and therefore load reduction is unnecessary. Future studies are needed to conduct risk and cost assessments for realistic decision-making. 相似文献
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Variation of cyanobacteria with different environmental conditions in Nansi Lake, China 总被引:1,自引:1,他引:0
Nansi Lake is located on the east line of the South-to-North Water Diversion Project in China. A comprehensive study was carried out to investigate the spatial and temporal distribution of cyanobacteria in the lake from June 2008 to May 2011 based on monthly sample monitoring from five stations. The effect of environmental factors on cyanobacterial abundance was also evaluated. The cyanobacterial community contained 15 genera and 23 species. The cyanobacterial abundance of each monitoring station ranged from 0 to 1.53× 107 cells/L with an average of 1.45×106 cells/L, which accounted for 11.66% of the total phytoplankton abundance. The dominant species of cyanobacteria were Pseudanabaena (32.94%) and Merismopedia (19.85%), not the bloom-forming algae such as Microcystis and Anabaena. In addition, the cyanobacterial community structure and water quality variables changed substantially over the survey period. Redundancy analysis (RDA) suggested that temperature and phosphorus were important environmental factors that affected cyanobacteria. Temperature was the most important factor affecting cyanobacterial abundance. The effect of phosphorus on cyanobacterial abundance was more notable in warm periods than in periods with low temperature. 相似文献
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钙、镁离子在水流作用下对铜绿微囊藻生长的影响 总被引:2,自引:0,他引:2
为了解在"引江济太"过程中大量钙、镁离子的引入对铜绿微囊藻生长的影响,本实验在控制温度和光照条件下,室内模拟不同钙、镁离子浓度在两个特征流速5 cm/s和15 cm/s下微囊藻的生长。实验结果表明,微囊藻藻密度随钙、镁离子浓度的增加而增加,流速在15cm/s下微囊藻最大藻密度(9 236.4×104cell/mL)是流速为5 cm/s下最大藻密度(2 873.72×104cell/mL)的3倍,流速为15 cm/s下微囊藻最大比增长速率均较5 cm/s下的高。这可能是在水流产生的剪切力作用下藻细胞胞外多糖增加,粘附更多的钙、镁离子更利于钙、镁离子迁移到胞内,同时胞外附着的钙、镁离子尤其钙离子形成桥联,使微囊藻细胞形成群体产生微环境利于微囊藻的生长。水流对微囊藻利用钙、镁离子有重要的影响,这为有效调水抑制蓝藻生长提供科学依据。 相似文献
37.
长江三角洲城市旅游与城市发展协调性及影响因素 总被引:1,自引:1,他引:0
城市旅游业作为城市服务业的重要部门,是推动城市发展的后续动力。运用信息熵赋权法和TOPSIS法相结合,从经济水平、社会发展、公共交通、城市绿化、环境保护、旅游发展6个方面对长江三角洲2003年和2008年的城市旅游与城市发展的协调性进行分析,借助ArcGIS软件的空间聚类法分析了城市旅游与城市发展协调水平的空间格局及演变,最后探讨影响因素。结果表明:长江三角洲16城市的城市旅游协调水平在研究期间相对稳定,具体可被划分为4个等级,第一、二等级城市数量较少,得分显著高于第三、四等级城市。城市旅游协调水平空间上存在较大差异,北部城市得分高于南部城市,基本格局保持稳定,呈现以上海、南京、杭州三个城市为核心向外围边缘城市的空间衰减。产业发展、城市旅游发展模式、城市旅游重大项目投资、区位条件是长江三角洲城市旅游协调水平产生空间分化的主要影响因素,可制定以城市旅游发展为手段的方式推动城市发展,促进区域均衡发展。 相似文献
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Distribution of heavy metals in sediments of the Pearl River Estuary, Southern China: Implications for sources and historical changes 总被引:2,自引:0,他引:2
The distribution of heavy metals (Pb, Zn, Cd and As) in sediments of the Pearl River Estuary was investigated. The spatial distribution of heavy metals displayed a decreasing pattern from the turbidity maxima to both upstream and downstream of the estuary, which suggested that suspended sediments played an important role in the trace metal distribution in the Pearl River Estuary. In addition, metal concentrations were higher in the west part of the estuary which received most of the pollutants from the Pearl River. In the sediment cores, fluxes of heavy metals were consistent with a predominant anthropogenic input in the period 1970-1990. From the mid-1990s to the 2000s, there was a significant decline in heavy metal pollution. The observed decline has shown the result of pollution control in the Pearl River Delta. However, it is noteworthy that the metal concentrations in the most recent sediment still remained considerably high. Taken together, the enrichment of heavy metals in sediments was largely controlled by anthropogenic pollution. 相似文献
40.
以沈阳市建设的第一座大型人工湖泊丁香湖为研究对象,针对丁香湖在基础设施建设、生态系统功能恢复等方面存在诸多现实问题为例,通过依势修整、科学引蓄、补水调换、人工生态浮岛和水生植物布设、局部复氧曝气和辅助的抑藻手段等综合治理措施,使丁香湖水质得到有效改善、生物多样性得到恢复。 相似文献