共查询到20条相似文献，搜索用时 140 毫秒
1.
[专稿]长江上游水库改变干流磷通量、效应与修复对策 总被引：7，自引：6，他引：1
磷主要随河川径流循环,是水域重要营养或污染物质,是长江及河口浮游生物限制因子.在自然与人类活动作用下,磷循环规律及变化对水生态环境具有重要作用.本文根据实测资料、理论和模型系统分析了长江磷自然循环属性、水库作用及可能的环境影响.长江磷以颗粒态为主,与泥沙关系密切,受水库影响大量沉积;颗粒磷的潜在生物有效磷(BAP)较高,总量超过人类排放;自然背景下磷与淡水系统关系较小,到河口及周边海域释放BAP是这里生态系统关键的营养资源;水库拦截使在底泥沉积并在缺氧环境释放的BAP成为河流上游潜在污染源.水库拦沙也破坏了下游河流泥沙的磷缓冲机制,增加环境脆弱性,降低污染承受能力,抬高水库下泄背景溶解磷浓度和河口碳、氮的相对程度,增加干流最下游大型水库污染和水华风险.另一方面,实测资料对比研究表明,我国河流地表水环境监测规范中的磷分析方法存在问题,采用"澄清样"方法使磷大量漏测,上下游、河湖库及汛枯期间磷通量监测口径不同、标准不一,很难适应流域一体化管理要求;依此监测的评估也会严重低估水库作用,忽视其拦磷和抬高背景溶解磷等机制,误导污染源解析,影响环境管理与决策.流域水库改变泥沙、磷及循环规律是当前长江干流环境条件的实质性改变,是长江保护生态面临的主要问题和修复重点之一,建议在大型水库持续挖泥用以功能性修复河流物质通量和消除上游潜在污染内源. 相似文献
2.
福建闽江水口水库凤眼莲空间分布特征及其动态 总被引：1，自引：1，他引：0
为研究闽江水口水库凤眼莲空间分布特征及动态变化,根据2001-2009年水口库区无云覆盖的24幅卫星遥感影像,构建研究区域凤眼莲干流-支流分布的空间结构,并通过建立端元的混合象元线性分解模型,对福建省水口水库不同时间、不同区域的凤眼莲分布特征进行系统分析,结果表明,随着时间的推移,凤眼莲的暴发区逐渐向下游迁移,同时,支流对研究区域凤眼莲的面积有重要影响,特别是河流较长、周边有人口居住的支流是凤眼莲源头治理的重点;各种人为或自然原因造成的水体富营养化、河流流速变缓等是凤眼莲泛滥的重要原因.建议针对研究区域上游及其周边进行养殖污染、工业污染整治,强化对污染源的监督管理,推进生态环境建设与保护,建设生态功能保护区等.本研究可为了解水口水库的凤眼莲时空分布规律,进而制定相应的预防与控制管理措施提供必不可少的数据基础和理论依据. 相似文献
3.
4.
密云水库区域大气-土-水污染过程复合相关源 总被引：5，自引：1，他引：5
采用密云水库15km处WMO区域空气污染本底站——上甸子站1990~2001年降水化学资料,并结合2002~2003年现场科学试验阶段获取的大气干沉降和湿沉降资料,从大气-土-水污染过程的复合相关源角度,综合分析了大气干、湿沉降以及白河沿岸农田、矿区和城镇污染源对密云水库的水质综合影响特征.分析结果表明,该时段密云水库区域大气降水中离子以SO42?,NO3?,NH4+和Ca2+为主;密云水库湿酸沉降量夏半年(4~9月)大于冬半年(10~3月),其年际变化呈上升趋势,年平均达1038.45t,最高年份(1996)达1766.31t,最低年份(1994)为604.02t;密云水库区域大气降水pH的多年平均值为5.20,降水呈弱酸性,pH值年际变化呈下降趋势.密云水库水体不同深层的pH值均大于7.0.pH值垂直和水平空间分布呈非均一性特征,同一区域pH值随水深呈下降趋势;2002年和2003年密云水库降尘量分别为13513.08t和3577.64t,春季降尘量为全年之首,分别占其全年的61.91%和44.56%.由于大气干、湿沉降中含有多种重金属元素及有害元素,它们可能在一定程度上对库水富营养化、潜在重金属污染以及库水酸化起“加剧”作用.上述综合分析结果揭示出密云水库区域大气-土-水污染过程复合相关源特征及其多圈层相互作用效应.另外,夏季(雨季)是局地土壤污染源由于受暴雨或强降水冲刷后通过入库水系山谷坡地汇流,引起区域性大气-土-水连锁污染过程,导致水库或河流水质污染.统计分析亦发现密云水库水质污染可能与水库周边及上游局部区域降水冲刷和汇流因素相关.水库污染物浓度变化与水库上游局地区域降水量呈较显著的相关,这些相关特征揭示了水库水质污染过程大气-土-水多圈层相互作用效应.提出了水库污染复合相关源分析法观点及其追踪入库水系上游污染源空间分布技术途径. 相似文献
5.
基于CORA-3算法对辽宁省的滑坡危险区域进行模式识别。将地形地貌、地层岩性、断裂构造、河流水系和年平均降雨量作为滑坡影响因子,在综合分析各因子影响的基础上,结合历史滑坡灾害的分布,利用CORA-3算法识别辽宁省内可能发生滑坡的危险区域。结果证明,识别出的区域与历史资料相吻合,更重要的是,识别出了一些尚未发生过滑坡的潜在危险区域。该识别方法可为滑坡灾害预警系统的建立提供理论依据。 相似文献
6.
基于粤港澳大湾区地震灾害风险评估的初步成果,分析了湾区城市群地震环境、承灾体分布和场地特点,提出了两种确定地震输入的设定地震原则,即潜在震源区设定地震原则和最大风险设定地震原则,按照这两种原则可以更加准确地进行城市群地震灾害风险评估。在前人工作的基础上,提出了考虑场地条件影响的地震灾害风险表达式,探索了适合三维模拟非一致激励地震动输入的建筑物和生命线工程灾害风险评估方法,提出了建筑物和生命线工程灾害风险评估中考虑场地影响的思路,为客观地评估城市群地震灾害和损失风险提出了可参考的建议。 相似文献
7.
2013年1月我国中东部强霾污染的数值模拟和防控对策 总被引：18，自引：0，他引：18
利用自主研制的嵌套网格空气质量数值预报模式（NAQPMS）模拟研究2013年1月我国中东部的持续强灰霾天气,初步评估灰霾天气下大气细颗粒物（PM2.5）时空分布特征、传输规律和防控力度．结果表明：这一模式能够合理反映灰霾天气下中东部PM2．5,的时空分布特征和演变规律．发现静稳天气京津冀地区仍旧存在显著的区域输送,并直接造成京津冀地区PM2．5浓度的累积,来自区域外的跨城市群输送对京津冀PM2．5浓度贡献为20％-35％,区域内输送的贡献为26％-35％,两者之和与局地污染源贡献相当．针对这次强霾的控制试验表明,当京津冀周边区域省份污染源不控制,河北、天津和北京的污染物排放需要消减90％,90％和60％以上才能实现京津冀区域PM2．5达标（二级标准）,表明京津冀灰霾污染防控不仅需要重视区域内的联防联控,同时也需要其他城市群的协同控制．气象一大气污染双向反馈机制对强霾的形成也有非常重要影响,可使京津冀部分地区细颗粒物月均浓度增加30％,忽视这种耦合作用会导致模式对重污染期间污染物浓度的低估． 相似文献
8.
为进一步了解人类活动及环境因子对太湖磷污染的贡献，揭示磷在太湖不同介质中的迁移转化规律，本文以太湖主要入湖湖区竺山湖、西部沿岸区、南部沿岸区和主要出湖湖区东太湖为对象，调查了表层水、上覆水、间隙水和沉积物中总磷(TP)分布的概况，分析了不同介质中磷的交换特征及其影响因素. 结果表明，表层水和上覆水TP浓度基本相当，平均值均为0.10 mg/L，上覆水和间隙水TP差异较大，间隙水平均浓度约为上覆水的7倍，表层沉积物TP含量为474~2160 mg/kg. 在本研究水域中，TP具有较强的沉积物吸附特性，沉积物作为“汇”的特征明显强于其“源”的特征，且磷的留存能力高度依赖于铁浓度. 空间分布上，入湖湖区磷污染程度明显高于出湖湖区，竺山湖和西部沿岸区存在较大的底泥污染释放风险，但竺山湖外源污染影响较内源污染更加突出，应列为当前太湖磷治理重点关注的区域，建议以控源截污作为竺山湖周边区域的治理重点. 西部沿岸区需注重外源和内源污染同步控制. 南部沿岸区周边区域需妥善处理好未来经济发展与废水排放负荷的关系. 相似文献
9.
无定河流域位于黄土高原与毛乌素沙地过渡带,水土流失严重,生态环境具有脆弱性和波动性。于2021年春季(4月)和秋季(10月)对无定河流域上、中、下游及其6条支流和流域内的3个淤地坝开展水生态系统调查,旨在厘清无定河流域底栖动物群落特征,构建底栖动物生物完整性指数并开展健康评价。无定河流域春季共采集到底栖动物105种,平均密度为181 ind./m2,平均生物量为0.760 g/m2,秋季共采集到底栖动物67种,平均密度为94 ind./m2,平均生物量为0.454 g/m2。通过对两季度研究区域内底栖动物27个生物参数开展分布范围检验、判别能力分析和相关性分析,构建无定河流域底栖动物生物完整性指数,对全流域40个样点(6个参照点和34个受损点)进行B-IBI健康评价。评价结果表明,总体上无定河流域底栖动物生物完整性较好,40个样点中春季有19个处于健康或亚健康状态,秋季有23个处于健康或亚健康状态,其中无定河上、中游干支流大都以健康和亚健康为主,无定河下游干支流以及3个淤地坝水体健康状况较差。在不同水土流失类型区域,底栖动物群落特征和生物完整性评价具有显著性差异。本研究结果可为无定河流域河流健康评估提供科学依据。 相似文献
10.
水体砷污染及其健康危害已成为一个备受关注的环境问题.本研究通过测定洞庭湖主要河口区表层沉积物砷含量、河蚬砷及砷形态（亚砷酸盐As（Ⅲ）、砷酸盐As（Ⅴ）、甲基砷酸MMA、二甲基砷酸DMA和砷甜菜碱AsB）含量，对表层沉积物砷的潜在生态风险和河蚬食用健康风险进行评价.结果表明，洞庭湖主要河口区表层沉积物砷含量在11.47~61.20 mg/kg之间，其水平分布规律表现为：南洞庭湖>东洞庭湖>西洞庭湖.河蚬砷含量范围为6.36~11.15 mg/kg，各砷形态含量排序为：AsB > As（Ⅴ） > DMA > As（Ⅲ） > MMA，各样地间不存在显著性差异.应用潜在生态风险指数法对表层沉积物中砷的潜在生态风险进行评价，各样地的潜在生态风险指数均值为23.09，潜在生态风险程度属于轻微级别.同时，利用致癌风险指数（CR）和危熵系数（HQ）评价经河蚬摄入无机砷给人体带来的潜在健康风险.洞庭湖主要河口区河蚬中无机砷的致癌风险CRiAs值达到了1.36×10-3~3.43×10-3（平均值为2.24×10-3），均显著超过USEPA推荐的可接受风险水平上限值（1×10-4），其危熵系数HQiAs值达到3.01~7.61（平均值为4.98，约为标准值的5倍），说明长期食用当地河蚬具有较高的致癌和非致癌健康风险.本研究结果对于了解洞庭湖沉积物和底栖动物的砷污染现状和风险水平具有重要意义，为该流域的砷污染控制及治理提供科学依据. 相似文献
11.
Dimitriou Elias Mentzafou Angeliki Markogianni Vasiliki Tzortziou Maria Zeri Christina 《Pure and Applied Geophysics》2014,171(6):977-995
Managing water resources, in terms of both quality and quantity, in transboundary rivers is a difficult and challenging task that requires efficient cross-border cooperation and transparency. Groundwater pollution risk assessment and mapping techniques over the full catchment area are important tools that could be used as part of these water resource management efforts, to estimate pollution pressures and optimize land planning processes. The Evros river catchment is the second largest river in Eastern Europe and sustains a population of 3.6 million people in three different countries (Bulgaria, Turkey and Greece). This study provides detailed information on the main pollution sources and pressures in the Evros catchment and, for the first time, applies, assesses and evaluates a groundwater pollution risk mapping technique using satellite observations (Landsat NDVI) and an extensive dataset of field measurements covering different seasons and multiple years. We found that approximately 40 % of the Greek part of the Evros catchment is characterized as of high and very high pollution risk, while 14 % of the study area is classified as of moderate risk. Both the modeled and measured water quality status of the river showed large spatiotemporal variations consistent with the strong anthropogenic pressures in this system, especially on the northern and central segments of the catchment. The pollutants identified illustrate inputs of agrochemicals and urban wastes in the river. High correlation coefficients (R between 0.79 and 0.85) were found between estimated pollution risks and measured concentrations of those chemical parameters that are mainly attributed to anthropogenic activities rather than in situ biogeochemical processes. The pollution risk method described here could be used elsewhere as a decision support tool for mitigating the impact of hazardous human activities and improving management of groundwater resources. 相似文献
12.
江苏省灌河流域污染特征及污染控制对策 总被引：1，自引：0，他引：1
基于2008年江苏省沿海地区灌河流域各城市污染源统计及调查数据,分析灌河流域主要污染物来源构成和污染特征,对污染物入河量进行计算及修正.结果表明:灌河的CODMn入河总量为36944.2 t/a,氨氮入河总量为4366.5 t/a,总氮和总磷入河总量分别为6507.4 t/a、444.6 t/a,各污染源均主要来源于农业污染.同时,针对灌河流域的污染特征,明确各类污染源的治理重点,提出了污染控制对策,为有效保护灌河水环境质量,支撑灌河口和灌河沿线的开发提供依据. 相似文献
13.
C. K. JAIN 《水文科学杂志》2013,58(4):577-588
Abstract The River Kali in western Uttar Pradesh, India is a typical water course for untreated municipal and industrial effluents. The river receives considerable amounts of waste every day from the industries and municipal area of Muzaffarnagar town. Agricultural runoff is the other major factor in pollution of the river water. The mass balance calculations conducted on the river reach indicate that nitrate and phosphate from the non-point sources constitute 32.4 and 11.2% of the total load, respectively. The resulting differential loading, if adjusted for uncharacterized non-point contribution to the load, may represent the total point sources load to the river minus any losses due to volatilization, settling, and/or degradation. Indirect monitoring using upstream/downstream sampling locations provides a viable alternative to conventional methods for measuring the changes in the concentration and/or load to the river. 相似文献
14.
In arid and semi-arid regions, many rivers experience extremely low flow conditions during seasonal dry periods. During these times, effluent from wastewater treatment plants can make up the majority of flow in the river. However, water quality in urban systems can also be strongly influenced by the natural or human-influenced flow regime and discharge from other anthropogenic sources such as industrial operations and runoff from impervious surfaces. In this study, we aimed to determine whether water quality was controlled primarily by wastewater discharge in an effluent-dominated river. Between May 2016–May 2019, we systematically measured water temperature, pH, dissolved oxygen, biochemical oxygen demand, and the concentrations of nitrate-N, ammonia-N, and orthophosphate in the South Platte River in the Denver metropolitan area, Colorado, USA. We found that, despite being an effluent-dominated river, wastewater treatment plant discharge was not the principal factor controlling water quality in many of the sampled areas. Non-point source pollution from impervious surfaces, delivered to the river through storm drains and minor tributary streams, also contributed to the high nutrient conditions in several locations. We also noted a strong seasonality in water quality, with higher concentrations of nutrients and higher biochemical oxygen demand in the winter months when wastewater effluent can make up more than 90% of the flow in the river. Thus, the interaction of discharge location and reduced seasonal flow produced spatio-temporal hot spots of diminished water quality. More stringent enforcement of water quality regulations may improve water quality in this system. However, a large portion of the pollution seems to be from non-point sources, which are very difficult to control. 相似文献
15.
16.
Seasonal and spatial characteristics of seawater and sediment at Youngil Bay, southeast coast of Korea 总被引：1，自引：0，他引：1
The seasonal geochemical characteristics of the seawater and sediments and the major factors causing heavy metal contamination were investigated at the Youngil bay and the Hyungsan river estuary in the Southeast Coast of Korea, where a world-scale steel-industry complex (Pohang iron and steel industrial complex, POSCO) is located. The seasonal and spatial distribution characteristics of temperature, dissolved oxygen (DO), pH, and nutrients of the seawater were studied at 45 fixed stations, especially focusing on the river mouth area. Sediments at 27 stations were examined during winter and summer to determine the major controlling factors for the distribution of metals, using correlation matrix and R-mode factor analyses, and to evaluate the pollution status, using the modified geoaccumulation (I(geo)(')) index. Temperatures for the effluent from the POSCO located at the Hyungsan river mouth were 2-3 degrees C higher compared to other sampling areas, due to the thermal discharge from the POSCO. The DO concentration of the surface water at the Pohang old port was as low as 2-4 mg/L. In spring, the DO value at the Hyungsan river mouth was higher than 12 mg/L, by the mass multiplication of phytoplanktons at the river mouth where seawater temperature and nutrients concentrations were relatively high, resulting in the pH value of higher than 8.3. The nitrogen to phosphorus (N/P) ratios at the river mouth were 20-150 times higher compared to other areas, implying that the nitrogen loading into this semi-enclosed bay is significantly higher than phosphorus and the major nitrogen sources are not only the domestic sewage from the city but the industrial wastewater from the POSCO and other steel factories nearby. The phosphorus concentrations at the Pohang old port were shown 3-10 times higher than those at other stations, due to the inflow of pollutants generated from the nearby ships anchoring and the release of phosphate from the bottom sediment. Results from the sediment analysis showed that the major controlling factors for the distribution pattern of each metal are grain size and organic carbon (C(org)) content. Based on the factor analysis, Al, Fe, Cr, Li, and Pb were shown strongly correlated with the mean grain size (Mz), whereas Cd, Cu, Zn, and Sn with the C(org) content. Results from the fractionation of the sedimentary metals into lattice and labile fractions to characterize the mobility of sediment metals showed that the mineral lattice fraction was high in the order of Al=K>Cr>Li>Sr>Fe, while the labile fraction, which might be released to the overlying water, was in the order of Pb>Zn>Cd>Cu>Ca>Sn. Evaluation of the sediment pollution status by applying (I(geo)(')) of 13 metals showed Cd, Cu, and Zn as high as 1-3 range at the old port. Even though the overall marine pollution mainly by the world-class steel industrial complex in this semi-enclosed bay area studied does not currently pose a serious threat, due to the seawater circulation and the large influx of river discharge, the countermeasures to implement the sediments concentrated with heavy metals, especially at the old port with no seawater circulation, are still warranted for this coastal water environment. 相似文献
17.
18.
The non-point source pollution in livestock-breeding areas of the Heihe River basin in Yellow River 总被引：4，自引：0，他引：4
Hongguang Cheng Wei Ouyang Fanghua Hao Xiyan Ren Shengtian Yang 《Stochastic Environmental Research and Risk Assessment (SERRA)》2007,21(3):213-221
A GIS-based distributed soil and water assessment tools (SWAT) model was used to simulate the runoff, sediment yield and the
load of the non-point source pollution in the Heihe River basin, which is a tributary and main water supply source of the
Yellow River. It is a typical stockbreeding area, and its industry and agriculture are not well developed. The main pollution
source of the Heihe River was livestock related non-point source pollution. With GIS and remote sensing techniques, a database
of non-point source pollution in the Heihe River basin was established. The SWAT model was parameterized for this area. The
pollution load and transportation rules such as nitrogen were illustrated. After several years of hard work, the situations
of point source pollution were more and more accurate. This paper provided an effective way to assess and calculate the pollution
load in the wide agriculture area in China. With the help of historical data formulated parameters, the non-point source load
and the theory of pollution load distribution were illustrated about the Heihe River basin. In 2000, the soluble N load in this area was 1.06 × 106 kg. By the simulation, the main pollution sources were in the south east of the basin, where
the pasturing areas located in the south-east of Ruoergai County and in north of the Hongyuan County. 相似文献
19.
《Acta Geochimica》2017,(3)
China is experiencing rapid urbanization that has changed the water quality of rivers, especially nutrient loads. In this study, a typical urban river located in a karst area, Chengguan River, was chosen to explore the influence of urbanization on river ecosystems based on nutrient concentration and nitrate isotopes. The results show monthly variability of water chemistry and nutrient concentration. Nutrient concentration in two tributaries and the mainstem showed significant spatial variability, with heavy N and P pollution in one tributary near a suburban area,indicating a response to different levels of urbanization.Measurements of nitrate dual isotopes suggest thatvolatilization, assimilation, nitrification, and denitrification all occur in the polluted river. Water chemistry and nitrate isotopes show that major nitrogen sources included domestic waste and agricultural input, such as chemical fertilizer and manure. The results suggest that urbanization increases nutrient concentrations and accelerates the riverine nitrogen dynamic, and point to the need to manage point sources of sewage effluents to improve the water quality of urban rivers in southwestern China. 相似文献
20.
采用2015年艾比湖流域54个采样点的10个地表水水质指标数据,首先利用水质指数模型(WQI)和地统计学方法对流域水质污染情况进行全局评价,然后利用层次聚类法、判别分析法和因子分析法分析艾比湖流域地表水丰水期和枯水期水质分异特征.在水质时空分异特征研究的基础上,利用主成分回归分析法对艾比湖流域水质进行污染源解析.结果表明:艾比湖流域丰水期WQI值介于38~70之间,枯水期WQI值介于31~71之间,艾比湖流域丰水期的地表水水质污染情况比枯水期严重,而艾比湖、博尔塔拉河和精河靠近艾比湖湖区的河道污染程度均比其他河道严重.由聚类分析和判别分析得出艾比湖流域丰水期和枯水期的水质采样点在空间上均被分成A、B两组,A组包括艾比湖湖区西部、奎屯河、古尔图河和四棵树河,B组包括艾比湖湖区东部、精河和博尔塔拉河.艾比湖流域丰水期和枯水期的水体主要受到化学需氧量、溶解氧、氨氮和悬浮物浓度等指标的影响,B组水质污染指标的值相比于A组的值偏高,B组区域内存在高污染企业,艾比湖流域水环境治理工作需主要集中在B组所包括的艾比湖湖区、博尔塔拉河和精河.(4)艾比湖湖区、精河和博尔塔拉河地表水体的污染主要来自于有机物污染和营养物质污染,其次为工矿业污染;而奎屯河、古尔图河、四棵树河地表水体的污染主要来自于有机物污染,其次为营养物质污染,生物污染的影响较为微弱.该研究结果可为艾比湖流域地表水水环境改善和治理提供一定参考. 相似文献