2016—2021年上海市杨浦区黄浦江流域水质变化与污染特征分析

为全面了解并跟踪上海市杨浦区黄浦江流域的水质情况，于2016年1月—2021年12月对杨浦区黄浦江流域的6个监测断面的地表水质量进行调查。采用单因子污染指数分析法和水质综合污染指数分析法，探究了杨浦区内黄浦江流域水质的污染变化特征。结果表明，自2017年杨浦区开展河道整治以来，流域总体水质明显改善，出口水质从重度污染提升到良好水平；居民区密集的虬江断面水质相对较差，后续需加强对虬江流域的污染排放管理；水质污染特征分析结果发现河道的主要污染物种类从氨氮（NH₃-N）转换为总磷(TP)，说明河道整治提升了河道的自净能力，水质改善效果显著；水质在非汛期优于汛期，气温、降雨、泵站放江和污水排放是影响水质的主要原因。     

“十三五”期间湖南省资江流域锑污染时空分布及污染治理成效分析

为掌握“十三五”期间湖南省资江流域锑污染的总体情况和变化趋势,采用数据统计分析方法对2016—2020年该流域水质锑变化特征进行研究,同时分析锑污染时间变化趋势和空间分布情况。结果表明,“十三五”期间,资江流域锑污染整体有较明显改善,尤其资江干流下游益阳市内的锑污染明显减轻,由2016年的超标率100%到2020年全部实现达标,各断面锑的质量浓度最大降幅达55.5%。资江支流中,2020年邵水断面锑质量浓度年均值较2018年下降了13.1%。资江流域的娄底、邵阳和益阳市均采取了一系列锑污染防治措施,使得资江流域锑污染整体有较明显改善。但资江支流中邵水和平溪江污染最重断面锑质量浓度年均值仍有超标,建议“十四五”期间加强流域内涉锑企业和历史遗留污染的治理,力争尽早实现资江全流域水质的全面达标。     

王港河流域水环境质量溯源调查分析

以王港河流域为研究对象,根据2016—2020年、2021年1月29日—31日2个时间段的水质历史监测数据、2020年高分遥感影像解译结果和对高锰酸盐指数、化学需氧量、氨氮、总磷指标的加密监测数据及现场核查,对王港河流域水环境质量范围进行了溯源调查分析。结果表明,2016—2020年,王港河流域水质逐年好转;遥感解译共289个工业企业地块,102个水产养殖地块,169个畜禽养殖地块,92个疑似污染水体地块;王港河流域上游水质明显好于下游,下游沿线支流水质较差,畜禽养殖污染占比较高,是影响水质的主要原因,此外,沿河乡镇生活污水和工业污水收集处理效率低,以及工业园区工业污染源、农场农田退水、水产养殖排水也是影响水质的重要原因。     

第二松花江面源污染时空分布规律的研究

第二松花江流域作为松花江干流的主要产水区,其污染年负荷关乎下游水质的安全。面源污染是第二松花江的重要污染来源,采用输出系数法估算面源污染年负荷量,通过流域土地利用类型、社会经济信息等因素,利用有资料年的统计数据,进行面源污染年负荷量在时间、空间上的展布,探寻第二松花江流域面源污染年负荷量的空间分布规律,为水环境管理部门提供理论依据。     

四川省水体富营养状况时空分布调查

采用综合营养指数法对四川省主要河流营养状况进行调查评价,分析其时空分布规律。结果表明,2009年四川省水体综合营养状态整体处于中营养水平。从空间分布情况看,水体营养状态从优到劣依次为金沙江、长江干流、岷江、嘉陵江、沱江,其中沱江处于轻度富营养状态。从时间分布情况看,除沱江流域月度间变化较小外,其他调查河流水体营养状态月度间变化呈双峰型"M"状,营养指数主峰发生在8月;长江干流、岷江和嘉陵江次峰发生在4—5月,金沙江次峰发生在10月。     

汉丹江(陕西段)水质变化特征分析

基于2008—2012年陕西省境内汉江、丹江干流14个断面的水质监测数据,采用单因子评价法、平均综合污染指数法和秩相关系数法等对该段水体的水质变化特征进行研究。结果表明,汉丹江(陕西段)断面水质以Ⅱ类、Ⅲ类为主,水质总体为优;水质综合污染状况呈下降趋势,其中汉江下降趋势显著;水质综合污染状况空间差异和区域分布特征明显,城区段污染大于郊区,各行政区段河流下游污染大于上游。流域水质主要受有机污染和营养盐因子影响,水体污染源主要来自城镇生活源和农业面源,工业源占比不大且排放行业较为集中。     

基于自动监测网络的湘江流域衡阳段铊污染原因分析

运用自动监测网络与实验室验证相结合的手段,通过测定湘江流域衡阳段干流与支流铊浓度,分析铊浓度与溶解氧含量、氨氮浓度及叶绿素a浓度等水质指标的关系,进而对湘江流域衡阳段铊污染进行原因分析。结果表明,2021年8月上旬,湘江流域衡阳段干流铊污染的来源主要为多支流污染汇入。其中,松木下游断面铊污染极有可能来源于支流上游企业排放,江东水厂断面铊浓度异常的原因主要为溶解氧降低、死藻富集。该案例可为我国铊污染应急监测及污染原因分析提供借鉴。     

基于非参数检验的水质变化趋势分析

综合应用Mann Kendall（M K）、季节性Kendall(S K)非参数检验方法和局部加权回归散点平滑法（LOWESS）分析东江流域长时间尺度（16 a）和短时间尺度（5 a）水质变化趋势,解析流量与点面源污染对水质指标变化的贡献。结果表明：东江干流DO呈明显下降趋势,TN呈明显上升趋势;二级支流淡水河整治成效显著,水质呈明显改善趋势。流域中上游水体耗氧有机物相对稳定且水平较低,而下游存在较大量耗氧有机物排放。S K检验有利于发现不同月份水情影响下的水质变化,检验出东江干流NH3-N呈明显下降趋势。M K（LOWESS）模型有利于解析各水质指标受上游集雨区汇水过程和点面源污染影响情况。     

基于多种方法的长江上游小流域水质综合评价

选取大河和巴关河流域2018—2022年水质监测数据,运用单因子评价法、Spearman秩相关系数法、综合污染指数法和主成分分析法,对流域水质状况、变化趋势及主要污染物特征进行综合评价分析。结果表明:2018—2022年,大河流域水质未达到地表水Ⅲ类标准;流域整体综合污染指数超过了1,为重污染,下游污染程度较重;营养指标和有机污染物指标存在显著正相关。巴关河流域水质达到了地表水Ⅲ类标准;流域整体综合污染指数未超过1,为中污染,上游污染程度较重;营养指标、有机污染物指标和重金属指标等均呈现出不同程度的相关性。巴关河流域水质总体优于大河流域。TP、NH₃-N、COD_Mn、COD_Cr和BOD₅是影响大河流域和巴关河流域水质的主要因子,均属于有机型及富营养化污染指标,主要来自生活源和农业源。建议选择适宜的评价方法开展系统性小流域污染溯源,分河段有针对性地开展小流域水环境治理。     

基于多元统计的宁夏典农河水质演替特征探究

宁夏典农河是黄河宁夏段的主要入黄排水沟之一，其水质状况对黄河宁夏-内蒙古段跨省流域水质安全至关重要。选取典农河2011—2020年10个监测点位的16项水质参数，采用综合污染指数(WPI)法，结合相关性分析、主成分分析、聚类分析等分析方法，综合分析该流域水污染特征，并对污染程度进行评估，对污染因子和污染原因进行解析，最终提出管控建议。研究结果表明：2011—2020年，影响典农河水质的主要污染因子为COD_Cr、NH₃-N、TP、TN,对应的年均浓度范围分别为22.3～71.5、0.64～9.09、0.173～0.662、2.89～21.52 mg/L,超标率分别为46%、8%、13%、85%。典农河2011—2020年WPI范围为0.59～1.74,重金属含量一直维持在较低水平。流域TN与TP年均浓度比值范围为20～84,整体呈下降趋势，且各监测点的差异性逐渐减小；BOD₅与COD_Cr浓度比值范围为0.02～0.19,反映出典农河流域水体可生化性较差。各监测断面污染物之间存在较强相关性，其中：流域C...     

汉江下游干支流浮游植物群落特征及其对水质的指示评价

浮游植物群落的动态变化可以全面、真实地反映水质的优劣,有利于了解水体污染状况的发展趋势.为及时掌握汉江下游水质变化,基于2019年3—12月汉江下游干流及主要支流浮游植物和水体理化指标监测数据,分析了浮游植物群落结构特征,并通过冗余分析研究了影响浮游植物群落结构的主要环境因子,同时运用浮游植物群落特征对汉江下游水质进行...     

Nutrients in the Changjiang River

N, P and SiO3-Si in the Changjiang mainstream and its major tributaries and lakes were investigated in the dry season from November to December, 1997, and in the flood season in August and October, 1998. An even distribution of SiO3-Si was found along the Changjiang River. However, the concentrations of total nitrogen, total dissolved nitrogen, dissolved inorganic nitrogen, nitrate and total phosphorus, total particulate phosphorus increased notably in the upper reaches, which reflected an increasing impact from human activities. Those concentrations in the middle and lower reaches of the Changjiang River were relatively constant. Dissolved N was the major form of N and the particulate P was the major form of P in the Changjiang River. The molar ratio of dissolved N to dissolved P was extremely high (192.5-317.5), while that of the particulate form was low (5.6-37.7). High N/P ratio reflected a significant input of anthropogenic N such as N from precipitation and N lost from water and soil etc. Dissolved N and P was in a quasi-equilibrium state in the process from precipitate to the river. In the turbid river water, light limitation, rather than P limitation, seemed more likely to be a controlling factor for the growth of phytoplankton. A positive linear correlationship between the concentration of dissolved N and the river's runoff was found, mainly in the upper reaches, which was related to the non-point sources of N. Over the past decades, N concentration has greatly increased, but the change of P concentration was not as significant as N. The nutrient fluxes of the Changjiang mainstream and tributaries were estimated, and the result showed that the nutrient fluxes were mainly controlled by the runoff, of which more than a half came from the tributaries. These investigations carried out before water storage of the Three Gorges Dam will supply a scientific base for studying the influences of the Three Gorges Dam on the ecology and environment of the Changjiang River and its estuary.     

黄河流域水质和工业污染源研究

为科学评价黄河流域的水质状况及工业企业污染源现状,根据黄河流域2018—2019年地表水和饮用水水源地水质监测数据,建立了综合反映流域水环境质量和可定量分析排名的城市水质指数;利用大数据技术分析工业企业水污染物排放数据,研究建立了企业环境信用动态评价体系。研究结果表明:2018—2019年,黄河流域城市水环境质量得到一定程度的改善,城市地表水环境质量优和良等级数量从17个增加到19个,饮用水水源地优等级城市数量从7个增加到11个;但黄河流域中游地区水污染问题较为严重,需要重点加强水污染控制。水质污染主要以点源工业污染为主,COD和氨氮排放量较多,COD和氨氮年日均排放浓度平均值分别为51.1、3.1 mg/L,工业废水处理率偏低;山西、陕西、河南等"高"风险企业数量较多,分别达到3 047、1 630、1 442家。建议加强黄河流域上下游、左右岸、干支流协同配合,加大水污染防治工作的深度和力度。     

Spatial–temporal variation and comparative assessment of water qualities of urban river system: a case study of the river Bagmati (Nepal)

The study presents the assessment of variation of water qualities, classification of monitoring networks and detection of pollution sources along the Bagmati River and its tributaries in the Kathmandu valley of Nepal. Seventeen stations, monitored for 23 physical and chemical parameters in pre-monsoon, monsoon, post-monsoon and winter seasons, during the period 1999-2003, were selected for the purpose of this study. The study revealed that the upstream river water qualities in the rural areas were increasingly affected from human sewage and chemical fertilizers. In downstream urban areas, the river was heavily polluted with untreated municipal sewage. The contribution of industries to pollute the river was minimal. The higher ratio of COD to BOD (3.74 in the rural and 2.06 in the urban) confirmed the increased industrial activities in the rural areas. An increasing trend of nitrate was found in the rural areas. In the urban areas, increasing trend of phosphorus was detected. The water quality measurement in the study period showed that DO was below 4 mg/l and BOD, COD, TIN, TP and TSS above 39.1, 59.2, 10.1, 0.84 and 199 mg/l, respectively, in the urban areas. In the rural areas, DO was above 6.2 mg/l and BOD, COD, TIN, TP and TSS below 15.9, 31, 5.24, 0.41 and 134.5 mg/l, respectively. The analysis for data from 1988 to 2003 at a key station in the river revealed that BOD was increasing at a rate of 1.8 mg/l in the Bagmati River. A comparative study for the water quality variables in the urban areas showed that the main river and its tributaries were equally polluted. The other comparison showed the urban water qualities were significantly poor as compared with rural. The cluster analysis detected three distinct monitoring groups: (1) low water pollution region, (2) medium water pollution region, (3) heavy water pollution region. For rapid assessment of water qualities using the representative sites could serve to optimize cost and time without loosing any significance of the outcome. The factor analysis revealed distinct groups of sources and pollutions (organics, nutrients, solutes and physicochemical).     

淮河流域淮安段着生藻类群落结构特征分析

于2021年5月对淮安境内淮河主要干支流8个点位的水质状况和着生藻类群落结构采样调查，应用3种多样性指数模型评价区域水生态健康状况，并探究影响着生藻类多样性的因素。结果表明：采样期间淮河流域淮安市域共检出着生藻类3门23科32属（种），由硅藻门、蓝藻门和绿藻门组成，硅藻门占绝对优势；多样性指数计算结果显示，流域水生态状况良好，整体表现为清洁-轻污型水体，淮河上游水质稍差于其他水域；结合水质监测数据与卫星遥感影像分析，认为生境状况是影响着生藻类群落分布的主要因素。     

Risk assessment for methylmercury in fish from the Songhua River,China: 30 years after mercury-containing wastewater outfalls were eliminated

This study aims to investigate the methylmercury contamination of fish from the Songhua River, China. A total of 328 fish representing various trophic levels were captured from ten reaches of the river and determined for methylmercury by gas chromatography method. Total mercury in fish, water and sediments from three typical reaches were analyzed simultaneously. Methylmercury concentrations in fish from the Second Songhua River and the mainstream of the Songhua River were 0.024 ± 0.016 and 0.015 ± 0.007 mg/kg fresh weight, respectively. The proportion of methylmercury to total mercury ranged from 21.8% to 69.7%, with the mean value of 42.6%. The observed methylmercury concentrations were much lower than the historical values and were generally within the reported literature range, and health hazard assessment showed no health risk from exposure to methylmercury by consuming fish from this river, demonstrating that mercury contamination of the Songhua River has been effectively controlled by nearly 30 years of environmental governance and natural purification.     

黄河呼和浩特段水环境质量时空变化分析

水环境质量评价是水资源可持续利用的重要前提，同时也是水环境管理与治理决策的重要依据。为科学评价黄河呼和浩特段水环境质量，基于基础资料数据库，遵循全面性、区域性、易量化性等原则，采用综合污染指数法详细分析了黄河呼和浩特段水环境质量的时空变化情况，进一步揭示了2020年水质季节变化规律，并对主要超标因子进行了深度解析。结果表明：随着一系列环境保护政策和管理措施的实施，2015—2020年黄河呼和浩特段水环境质量综合指数下降了75.87%。在时间尺度上，各断面的水环境质量综合指数平均值由2015年的93.81下降至2020年的22.64,整体水环境质量评价等级由G4转为G2,对应的水环境质量状况由中度污染转为较好；在空间尺度上，上游水环境质量优于下游，城区段水环境质量较差。此外，评价结果显示，部分水体当前仍存在氨氮超标问题。评价结果较为客观地反映了黄河呼和浩特段的水环境质量，可为水环境管理提供决策依据。     

流域污染分异特征及成因分析

目前中国地表水十大流域水质差异较大,以2013年国家监测网监测数据为例,重度污染水质断面多分布于海河、淮河和黄河中下游地区。究其原因,黄河、海河、淮河单位面积水资源量较少、水资源利用率较高、水体自净能力下降;同时长年居高不下的污染物排放累积效应严重影响水质改善;重污染行业集聚、排放强度大、城市化进程较快、第二产业比重较高等因素加剧了水资源的供需矛盾,最终影响水质改善。     

Characteristics of and Human Influences on Nitrogen Contamination in Yellow River System, China

Nitrogen (N) contamination in the Yellow River mainstream and its tributaries was studied using data from 1960 to 2000 from 312 monitoring sites in the Yellow River system. Data showed that N concentrations in the Yellow River have increased since 1960, especially after 1990. N concentrations in the Yellow River mainstream increased from the upper reaches (less than 1.0 mg L(-1) for TN and less than 0.10 mg L(-1) for NH4(+)-N) to lower reaches (higher than 4-5 mg L(-1) for TN and higher than 1.0 mg L(-1) for NH4(+)-N). However, the highest N contaminations (50-250 mg L(-1) for TN and 10-20 mg L(-1) for NH4(+)-N) was found in some tributaries, which was attributed as an effect of industrial wastewater and municipal sewage. Nitrogen concentrations from several monitoring sites were positively correlated with several regional socio-economic indices, such as population density, fertilization rates, livestock, industrial input and GDP. Depending on location, seasonal N concentrations contrasted among watersheds. Monitoring stations located in rural and agricultural areas showed higher N concentrations during the flood season while those located in areas with urban and industrial centers showed higher N concentration during the dry season. Mainstream flow and N concentrations showed a strong inverse relationship; with higher N concentrations as the river flow declined. Intensive water extraction for agricultural irrigation and increasing N input to the river from fertilized agricultural fields could explain the increasing N concentrations during extensive droughts.     

Water quality trends in the Delaware River Basin (USA) from 1980 to 2005

In 1940, the tidal Delaware River was ??one of the most grossly polluted areas in the United States.?? During the 1950s, water quality was so poor along the river at Philadelphia that zero oxygen levels prevented migration of American shad leading to near extirpation of the species. Since then, water quality in the Delaware Basin has improved with implementation of the 1961 Delaware River Basin Compact and 1970s Federal Clean Water Act Amendments. At 15 gages along the Delaware River and major tributaries between 1980 and 2005, water quality for dissolved oxygen, phosphorus, nitrogen, and sediment improved at 39%, remained constant at 51%, and degraded at 10% of the stations. Since 1980, improved water-quality stations outnumbered degraded stations by a 4 to 1 margin. Water quality remains good in the nontidal river above Trenton and, while improved, remains fair to poor for phosphorus and nitrogen in the tidal estuary near Philadelphia and in the Lehigh and Schuylkill tributaries. Water quality is good in heavily forested watersheds (>50%) and poor in highly cultivated watersheds. Water quality recovery in the Delaware Basin is coincident with implementation of environmental laws enacted in the 1960s and 1970s and is congruent with return of striped bass, shad, blue crab, and bald eagle populations.