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71.
洱海富营养化时空分布模糊评价及成因对策分析   总被引:7,自引:0,他引:7  
运用模糊方法对洱海富营养化时空分布进行了研究,发现洱海营养化状况从1988~1991年呈上升趋势,且其年内分布规律为冬春低、夏秋高。空间分布,则表现为南部、北部、西部、东部较相应的中部高。并对此规律的成因进行了分析,提出洱海富营养化防治对策。   相似文献   
72.
滇池富营养化成因分析   总被引:14,自引:2,他引:12       下载免费PDF全文
滇池富营养化是湖泊生态环境演变过程的景观显示,是湖泊生物生产力在必需的营养条件和适宜的环境条件相互作用下发生发展的生态过程。其生态演变因素可分为“自然的"与“人为的"两种。营养盐的大量输入是滇池富营养化的主要原因:适宜的自然环境是发生富营养化的重要条件:人类活动的强度干预,加速了滇池的富营养化。   相似文献   
73.
The accelerated eutrophication of freshwaters and to a lesser extent some coastal waters is primarily driven by phosphorus (P) inputs. While efforts to identify and limit point source inputs of P to surface waters have seen some success, nonpoint sources remain difficult to identify, target, and remediate. As further improvements in wastewater treatment technologies becomes increasingly costly, attention has focused more on nonpoint source reduction, particularly the role of agriculture. This attention was heightened over the last 10 to 20 years by a number of highly visible cases of nutrient-related water quality degradation; including the Lake Taihu, Baltic Sea, Chesapeake Bay, and Gulf of Mexico. Thus, there has been a shift to targeted management of critical sources of P loss. In both the U.S. and China, there has been an intensification of agricultural production systems in certain areas concentrate large amounts of nutrients in excess of local crop and forage needs, which has increased the potential for P loss from these areas. To address this, innovative technologies are emerging that recycle water P back to land as fertilizer. For example, in the watershed of Lake Taihu, China one of the largest surface fresh waters for drinking water supply in China, local governments have encouraged innovation and various technical trials to harvest harmful algal blooms and use them for bio-gas, agricultural fertilizers, and biofuel production. In any country, however, the economics of remediation will remain a key limitation to substantial changes in agricultural production.  相似文献   
74.
对2001~2011年固城湖水环境污染状况评价与时空变化特征分析的基础上,探讨了固城湖的特征污染物及污染来源。结果表明,固城湖水质污染的主要超标因子为TN和TP;总体水质呈现先恶化再改善的趋势,污染由拦河网水域向小湖区水域扩散;固城湖湖体水质基本上劣于水环境功能区划要求;固城湖特征污染物为COD+M n、NH4-N、TN、TP、BOD 5;富营养化程度不断加重,之后又有所改善;氮磷污染的主要来源是水产养殖污染。  相似文献   
75.
根据《地表水环境质量评价办法》中规定的方法,对沈阳辉山水库进行了水质和富营养化状态评价,并对污染源和水质污染特性进行了分析。结果显示:水库水质类别为劣Ⅴ类,水质状况为重度污染。富营养化综合营养状态指数为34.44,辉山水库水质为中营养化水平,水库没有藻类水华的产生。水库主要污染指标为总磷、总氮和悬浮物,分别超出国家地表水Ⅲ类标准的14.2倍、5.85倍和2.72倍。整个库区水质变化不均匀,水质变化受库区沿岸污染物排放影响较大,辉山明渠上游和某工厂暗渠排污口输入是水库主要污染源,库区周围动迁后的荒地和蚯蚓养殖,是辉山水库地面径流和农业污染污染源。  相似文献   
76.
基于指标规范值的富营养化评价的TOPSIS模型   总被引:1,自引:0,他引:1  
当指标较多时,传统的TOPSIS模型构造标准化决策矩阵的工作量大,且正、负理想点的确定未规范化,主观性较强。提出在适当设定富营养化指标"参照值"及指标值的"规范变换式"基础上,将同级标准的规范值相近的指标归为一类,因而同属一类的指标可设计为相同的标准化决策矩阵,大大减少工作量。将指标规范值的TOPSIS模型用于洋河水库的富营养化评价,结果与实况相符合。基于指标规范值的TOPSIS模型不仅简单、实用,而且使正、负理想点确定能规范化。  相似文献   
77.
根据浙江省舟山海洋生态环境监测站多年资料,对浙江省近岸海域环境功能区达标趋势及影响因素进行分析。结果表明,2009年浙江近岸海域环境功能区平水期、丰水期、枯水期达标面积分别为9541、10715、842km2,全年达标面积7333km2,占所监测海域面积的16.4%。浙江省近岸海域环境功能区水质达标的主要超标指标为无机氮和活性磷酸盐,另有部分区域溶解氧、化学需氧量、pH指标超标。整个杭州湾水体处于严重富营养化水平,象山湾和泗礁-大衢-岱山岛以西的舟山海域处于中度富营养化水平。东经122度以东的舟山海域及浙中南近岸海域处于轻度富营养或贫营养水平,2002年以来浙江近岸海域水体的富营养化程度逐步下降。2001—2004年近岸海域环境功能区达标率均低于3%,达标区主要分布在舟山海域,2005年开始达标区域扩展到温州海域,"十一五"以来浙江省近岸海域环境功能区水质达标率呈增加趋势。  相似文献   
78.
2009年4-5月对抚河下游分流处及河口进行浮游生物及水质状况的调研,基于优势种评价法和污水生物系统法并结合化学评价对其富营养化状况进行评价.共检出11大类,230种浮游生物.生物优势种评价法与化学营养状况指标法分析均表明,抚河下游分流处、东支河口和西支河口水体均呈富营养型.污水生物系统评价结果表明,抚河下游分流处水体介于多污染带与β中污带之间;东支河口水体介于多污染带与β中污带中间;西支河口水体处于多污染带.与分流处相比,河口浮游生物密度激增,还增加了金藻、黄藻、甲藻等浮游植物种类,说明河口富营养化程度比分流处严重,其中金溪湖处河口营养化程度最严重.  相似文献   
79.
Here is presented some of the first information on interactions of compounds produced by cyanobacteria and green algae with estrogen receptor signaling. Estrogenic potency of aqueous extracts and exudates (culture spent media with extracellular products) of seven species of cyanobacteria (10 different laboratory strains) and two algal species were assessed by use of in vitro trans-activation assays. Compounds produced by cyanobacteria and algae, and in particular those excreted from the cells, were estrogenic. Most exudates were estrogenic with potencies expressed at 50% of the maximum response under control of the estrogen receptor ranging from 0.2 to 7.2 ng 17β-estradiol (E2) equivalents (EEQ)/L. The greatest estrogenic potency was observed for exudates of Microcystis aerigunosa, a common species that forms water blooms. Aqueous extracts of both green algae, but only one species of cyanobacteria (Aphanizomenon gracile) elicited significant estrogenicity with EEQ ranging from 15 to 280 ng 17β-estradiol (E2)/g dry weight. Scenedesmus quadricauda exudates and extracts of Aphanizomenon flos-aquae were antagonistic to the ER when coexposed to E2. The EEQ potency was not correlated with concentrations of cyanotoxins, such as microcystin and cylindrospermopsin, which suggests that the EEQ was comprised of other compounds. The study demonstrates some differences between the estrogenic potency of aqueous extracts prepared from the same species, but of different origin, while the effects of exudates were comparable within species. The observed estrogenic potencies are important namely in relation to the possible mass expansion of cyanobacteria and release of the active compounds into surrounding water.  相似文献   
80.
Gren IM  Destouni G 《Ambio》2012,41(2):151-160
Successful implementation of an international nutrient abatement agreement, such as the Baltic Sea Action Plan (BSAP), requires consistent understanding of the baseline nutrient loads, and a perception of acceptable costs and fairness in targeted reductions of these base line loads. This article presents a general framework for identifying the implications of divergence between different nutrient load quantification approaches, with regard to both cost and fairness criteria outcomes, for the international agreement to decrease nutrient loads into the Baltic Sea as presented in the BSAP. The results indicate that even relatively small divergence in the nutrient load quantification translates into relatively large differences in abatement cost for different Baltic Sea countries. A robust result, irrespective of differences in nutrient load assessments, is a conflict between abatement cost effectiveness and fairness, with relatively poor countries facing heavy abatement cost burdens for cost-effective international load abatement.  相似文献   
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