基于MIKE 21的汾河水库挟沙水流水质数值模拟研究

为了揭示悬浮泥沙(SSC)对水库水质的影响规律,对汾河水库进行样品收集和长期水质监测,采用水动力模型与泥沙转移和富营养化模型相结合的方法,将这三者关联耦合,并通过实测数据对模型进行参数率定和验证,分析含沙水和不含沙水中总氮(TN)、总磷(TP)、叶绿素a(Chla)、溶解氧(DO)四项指标,得出两者对水质造成的影响。结果表明:SSC对TN、TP的去除作用明显,对Chla、DO浓度分布影响较小,并计算了污染物的释放量以及贡献率,得出TP的负荷仅为16.47t,而贡献率高达25.25%。因此在汾河的污染控制方面应侧重削减磷,进而改善汾河地区的污染现状。     

化成水库饮用水源地富营养化状况的分析与评价

根据2014~2016年对化成水库的水质监测,采用综合营养状态指数法和模糊综合评价法对水库富营养化现状进行了评价。结果表明两种评价方法得出的结果一致,该水库在此三年间持续处于中营养状态。对该点位水质富营养化变量指标(COD_(Mn)、NH_3-N、TN和TP)进行特征分析,TN和TP均为Ⅲ类,COD_(Mn)处于Ⅱ—Ⅲ类,NH_3-N达到Ⅱ类。分析该区域水质各指标为NH_3-N和TN污染主要来源是点源污染,而TP和COD_(Mn)主要来自非点源污染。根据分析结果对化成水库富营养化进行成因分析并提出科学建议。     

四川升钟水库水质评价及污染负荷分析

选取高锰酸盐指数（CODMn）、五日生化需氧量（BOD5）、总氮（TN）、总磷（TP）4项监测指标，采用单因干评价法、综合污染指数法、内梅罗污染指数法、模糊综合评价法及水质标识指数法对升钟水库2004～2010年水污染特征进行分析与评价，结果表明：水质标识指数法比较适合升钟水库水体富营养化评价；单因子水质标识指数显示，水库主要污染物为总氮（TN）、总磷（TP），基本呈现富营养状态；2008年水质最差，2010年水质达到Ⅱ类标准；7年Iwq的平均值Ave（Iwq）=3．393，Ave（Iwq）未达到国家Ⅱ类水质标准。近7年综合水质标识指数（Iwq）在不同时点上具有高-低演化规律，总体趋向好转。通过计算2006年N、P污染负荷，TN、TP入库主要源于水产养殖，其贡献率分别为：55％、82％，升钟水库TN、TP是合理容量的1．97～2．32倍。应严格控制水库网箱肥水养殖。研究结果对指导升钟水库水污染防治与水资源管理具有重要的意义。     

淄博田庄水库水质分布特征与富营养化评价

根据田庄水库的自然地理和水文特征，作者选择7个监测点，定量监测了水库和入库河段的水质分布特征，并采用卡森水质营养状态指数法和特里指数法对水库富营养化情况进行综合评价。研究结果表明，在所有监测点中NH4^＋-N、TN、TP均严重超标，田庄水库现状水体已经达到轻度富营养化水平；从入库、库区至出库的表层水体中，TP的浓度逐渐降低；除DO外，在水库的垂直剖面上，其他指标浓度随深度的增加呈增加的趋势。     

黑龙滩水库污染源及水质演变趋势分析

在黑龙滩水库进行污染源调查及水质分析的基础上,探讨了水库水质和营养盐变化趋势及其主要影响因素。污染源调查结果表明,黑龙滩水库流域CODCr、NH3-N、TN和TP产生量分别为3664.23 t/a、280.37 t/a、335.49 t/a和74.96 t/a,水库污染负荷主要集中在农村面源污染、畜禽养殖污染和旅游污染3个方面,其污染物产生量占总污染负荷的93%以上;水质分析表明,自2006年后,黑龙滩水库水质逐渐好转,但2010后CODMn有上升趋势,2012年主要超标因子为CODMn和TP;2004年~2012年,黑龙滩水库营养状况由贫营养向中营养发展,并在2010年~2012年稳定在中营养状态,水库富营养化整体呈现加剧趋势。     

南充市升钟水库水污染治理成效探讨

根据升钟水库近5年的水质监测数据,探讨了库区的水质现状和营养盐变化趋势及污染治理措施成效。数据显示,与2006年相比,升钟水库营养状况由轻度富营养向中营养发展,2014~2018年稳定在中营养状态。2014年起,TP、TN快速下降,受上游输入污染、旅游污染等影响,TP2016年开始上升,TN2017年开始上升;受农业面源污染、地表径流等因素影响,CODMn2015年起呈持续上升趋势。升钟水库的水污染治理成效显著,但仍需采取有力控制措施,防止水体向富营养化发展。     

磁湖湖滨带水质模糊综合评价

为了解磁湖周边污染情况,分别在2018年9月和12月通过对磁湖湖滨带8个点位进行取样监测,运用模糊数学综合评价法,分析了各点位氨氮(NH3-N)、总氮(TN)、总磷(TP)、溶解氧(DO)、五日生化需氧量(BOD5)、化学需氧量(CODCr)、高锰酸盐指数(CODMn) 7项指标。结果表明,磁湖南半湖和北半湖水质差异性较大,南半湖水质相对较差,需要重点加强对磁湖南半湖污染防治的监督和管理。     

城市浅水湖QQD耦合模型的构建及其应用研究

为了更有效地治理城市浅水湖的水环境污染问题,通过构建"水量-水质-水动力学"耦合模型(Water Quantity-Water Quality-Water Dynamic Coupling Model,QQD耦合模型),并以位于四川大学江安校区内的明远湖作为算例。根据2016年4月上旬~9月下旬对钙镁离子、NH3-N、TP和DO共4个水质指标的跟踪监测数据,利用QQD耦合模型模拟得到湖内水体流场以及各种水质污染物在流场中的分布范围,进而分析并明确了污染物的主要来源和影响程度,同时还提出综合整治湖内水污染治理对策与措施的建议。此外,还利用SPSS软件将实测的水质污染数据拟合出多元线性回归方程进行了验证。结果表明,采用文中所建立的QQD耦合模型可以适用于类似的城市浅水湖水质污染情况模拟计算。     

秦皇岛市农业面源污染特征分析

对2011年秦皇岛市农业污染源进行分析并测算各污染物排放量,结果表明,农业面源COD排放量为38768．27t,NH3-N为7593．71t,TN为15684．63t,TP为7821．18t;昌黎县是秦皇岛市农业面源污染最重的污染区域;农村生活源对COD排放量的贡献率最大,种植业对NH3-N、TN和TP排放量的贡献率最大。     

洪泽湖底栖动物群落结构及水质季节变化分析

为阐明洪泽湖底栖动物的群落结构及水质变化状况,采用生物多样性指数法、综合污染指数、CCA分析等方法,对洪泽湖的底栖动物群落结构空间布局及其水质状况进行了季度调查,探究环境因子对底栖动物生长的影响规律。结果表明:(1)底栖动物种类以甲壳纲、多毛纲、双壳纲为主;(2)CPI分析表明,TN、TP是洪泽湖主要的超地表水Ⅲ类水环境标准的项目,入湖过水区域水质污染高于其他区域,且春冬TN超标为主,夏秋TP超标为主;(3)典范对应分析显示,氨氮、透明度、叶绿素a是影响底栖动物分布的主要环境因素。研究表明洪泽湖底栖动物群落组成优势种主导格局显著,生物多样性不高,群落组成和水质状况受过水水体影响极大,生态系统保护和修复需加强对周边水域生态系统的关注,尤其是淮河水系。     

AN ASSESSMENT OF SEDIMENT PHOSPHORUS INACTWATION,KEZAR LAKE,NEW HAMPSHIRE1

ABSTRACT: Aluminum sulfate and sodium aluminate were utilized as sediment phosphorus inactivants to improve the water quality of a northeastern eutrophic lake. A four-year monitoring program has provided an extensive lake-database utilized to evaluate the short-and long-term effectiveness of sediment phosphorus inactivation as a lake restoration technique. An immediate impact of treatment was marked by a reduction in hypolimnetic BOD and dissolved oxygen deficit, lower chlorophyll-a and phosphorus concentrations, improved transparency, and the elimination of obnoxious blue-green phyto-plankton blooms. For two to three years after treatment, these pa-rameters continued to exhibit both less variability and improved values over the pre-treatment conditions. The improved water quality conditions warranted an upgrade of the lake trophic status from eutrophic to mesotrophic. Four years after the treatment, the mean hypolimnetic total phosphoru.s and chlorophyll-a have increased and transparency has decreased from initial post-treatment levels. Although long-term trends show water quality decreasing since the treatment, the water quality has stabilized at a level suitable for recreation. A major benefit is an increase in the average attendance at the lake by almost 2,000 people per summer.     

四川大学江安校区景观水体水质特征分析

本文以四川大学江安校区景观水体为研究对象,通过近一年,共6次的水质监测采样,研究氨氮、总磷、溶解氧、高锰酸盐指数等水质指标的时空分布特征及变化规律并进行单因子评价。分析了水体富营养化和湖中鱼类的死亡原因并讨论了餐厅排污的影响。研究结果表明:总磷、氨氮和溶解氧是主要污染指标,可导致"水华"、死鱼等问题。最后,提出了相应的治理对策与措施建议。     

Relative Importance of Water‐Quality Stressors in Predicting Fish Community Responses in Midwestern Streams

Fish, habitat, and water chemistry data were collected from 98 streams in the midwestern United States, an area dominated by intense cultivation of row crops, in order to identify important water‐quality stressors to fish communities. We focused on 10 stressors including riparian disturbance, riparian vegetative cover, instream fish cover, streambed sedimentation, streamflow variability, total nitrogen, total phosphorus, minimum dissolved oxygen, pesticides, and bed sediment contaminants. Fish community response variables included a measure of observed/expected taxonomic completeness; species‐specific tolerances to nitrogen, phosphorus, dissolved oxygen, and water temperature; the percent of species classified as macrohabitat generalists; and an index of pesticide toxicity to fish. Multivariate analysis indicated that total nitrogen was the most important stressor, signifying that fish communities were responding to total nitrogen despite relatively high levels common to an agricultural setting. Individually, fish taxonomic completeness decreased with increasing streambed sedimentation, whereas fish community tolerance to total phosphorus increased with increasing streambed sedimentation, riparian disturbance, and total nitrogen. These findings underscore the importance of multiple biological response metrics to better understand the effects of water‐quality stressors on fish communities and highlight the complex relations between total phosphorus and fish communities.     

Nutrient and sediment concentrations and corresponding loads during the historic June 2008 flooding in eastern Iowa

A combination of above-normal precipitation during the winter and spring of 2007-2008 and extensive rainfall during June 2008 led to severe flooding in many parts of the midwestern United States. This resulted in transport of substantial amounts of nutrients and sediment from Iowa basins into the Mississippi River. Water samples were collected from 31 sites on six large Iowa tributaries to the Mississippi River to characterize water quality and to quantify nutrient and sediment loads during this extreme discharge event. Each sample was analyzed for total nitrogen, dissolved nitrate plus nitrite nitrogen, dissolved ammonia as nitrogen, total phosphorus, orthophosphate, and suspended sediment. Concentrations measured near peak flow in June 2008 were compared with the corresponding mean concentrations from June 1979 to 2007 using a paired t test. While there was no consistent pattern in concentrations between historical samples and those from the 2008 flood, increased flow during the flood resulted in near-peak June 2008 flood daily loads that were statistically greater (p < 0.05) than the median June 1979 to 2007 daily loads for all constituents. Estimates of loads for the 16-d period during the flood were calculated for four major tributaries and totaled 4.95 x 10(7) kg of nitrogen (N) and 2.9 x 10(6) kg of phosphorus (P) leaving Iowa, which accounted for about 22 and 46% of the total average annual nutrient yield, respectively. This study demonstrates the importance of large flood events to the total annual nutrient load in both small streams and large rivers.     

Identification of pollution of Tapeng Lagoon from neighbouring rivers using multivariate statistical method

This work investigated water samples collected from Tapeng Lagoon and three neighbouring rivers (the Kaoping River, Tungkang River and Lingbeng River) in Taiwan, Republic of China. Canonical discriminant analysis was applied to identify the source of pollution in neighbouring rivers outside Tapeng Lagoon. The two constructed discriminant functions showed a marked contribution to all discriminant variables, and the total nitrogen, algae, dissolved oxygen and total phosphate were combined as the nutrient effect factor. The recognition capacities of the two discriminant functions were 95.6% and 4.4%, respectively. The water quality in the Kaoping River most strongly controlled the water quality in Tapeng Lagoon. Disassembling the oyster frames and fishery boxes had improved the water quality markedly. The methodology and results provide useful information concerning watershed management and may be applicable to other basins with similar properties that are experiencing similar coastal environmental issues.     

Effect of reservoir flushing on downstream river water quality

The effect of short-term reservoir flushing on downstream water quality in the Geum River, Korea was studied using field experiments and computer simulations. The reservoir release was increased from 30 to 200 m(3)/s within 6 h for the purpose of this experiment. The flushing discharge decreased the concentrations of soluble nitrogen and phosphorus species considerably, but the experimental results revealed a negative impact on organic forms of nutrients and biochemical oxygen demand (BOD). A dynamic river water quality model was applied to simulate the river hydraulics and water quality variations during the event. The model showed very good performance in predicting the travel time of flushing flow and the variations of dissolved forms of nitrogen and phosphorus constituents. However, it revealed a limited capability in simulating organic forms of nutrients and BOD because it does not consider the re-suspension mechanism of these constituents from sediment during the wave front passage.     

WATER QUALITY AND SOURCE OF FRESHWATER DISCHARGE TO THE CALOOSAHATCHEE ESTUARY,FLORIDA1

ABSTRACT: The Caloosahatchee River has two major sources of freshwater one from its watershed and the other via an artificial connection to Lake Okeechobee. The contribution of each source to the freshwater discharge reaching the downstream estuary varies and either may dominate. Routine monitoring data were analyzed to determine the effects of total river discharge and source of discharge (river basin, lake) on water quality in the downstream estuary. Parameters examined were: color, total suspended solids, light attenuation, chlorophyll a, and total and dissolved inorganic nitrogen and phosphorus. In general, the concentrations of color, and total and dissolved inorganic nitrogen increased, and total suspended solids decreased, as total discharge increased. When the river basin was the major source, the concentrations of nutrients (excepting ammonia) and color in the estuary were relatively higher than when the lake was the major source. Light attenuation was greater when the river basin dominated freshwater discharge to the estuary. The analysis indicates that water quality in the downstream estuary changes as a function of both total discharge and source of discharge. Relative to discharge from the river basin, releases from Lake Okeechobee do not detectably increase concentrations of nutrients, color, or TSS in the estuary.     

SPRINGFLOW EFFECTS ON CHEMICAL LOADS IN THE SNAKE RWER,SOUTH-CENTRAL IDAHO1

ABSTRACT: The 150-kilometer middle reach of the Snake River (middle Snake) in south-central Idaho receives large quantities of water from springs discharging along the north side of the river from the regional Snake River Plain aquifer. Water-quality samples collected from nine north-side springs in April 1994 indicated that springs in the upstream part of the reach had larger concentrations of dissolved solids, dissolved nitrate, total nitrogen, tritium, and heavy isotopes of hydrogen and oxygen than to springs in the downstream part of the reach. Because the spring chemistry varies in the reach, discharge from the springs resulted in a degradation in water quality in some parts of the middle Snake and improvements in water quality in other parts. Depending on the annual discharge in the Snake River, the contribution from the north-side springs represented 33 to 66 percent of the discharge, 32 to 57 percent of the dissolved solids, 26 to 50 percent of the total nitrogen, and 7 to 14 percent of the total phosphorus transported annually from the middle Snake. Synoptic sampling showed that the north-side springs contributed 84 percent of the discharge and 35, 40, and 10 percent of the dissolved solids, total nitrogen, and total phosphorus load, respectively, to the Snake River during the peak of the irrigation season in 1994.     

Investigation of long-term river water quality variations using different urbanization indices and assessment of common scientific perspectives of urbanization on water quality

This study investigated the water quality variation spanning 30 years (1986–2017) in 16 catchments of Hong Kong against different urbanization indices, namely, built area fraction; population; and product of population and built area fraction. Pearson correlations of three different periods of time (1988–1990, 1998–2000, and 2015–2017) indicated that water quality trends were dependent on the urbanization index. Total solids, nitrite-nitrogen, total phosphorus, electrical conductivity, dissolved oxygen, and flow rate had significant deteriorative trends (Pearson r > 0.5 and p < 0.05) with population and product of built area and population. Results also interpreted that built area fraction and product of built area and population were the worst and best indices that represented urbanization and/or its impacts, respectively. Mann-Kendall test for the entire 30 year period showed that water quality had improved with time with respect to certain water quality parameters (e.g., dissolved oxygen, ammoniacal nitrogen and total suspended solids). The results portrayed that although the urbanization of catchments had increased with time, the river water quality with respect to many parameters showed signs of improvement and the legislative measures implemented seemed to be effective in controlling pollution.