Water quality estimation in consideration of pollutant runoff and internal production in Lake Biwa, Japan.

Lake Biwa is the largest lake in Japan, and water quality in the lake is heterogeneous. Therefore, it is important for water quality management that spatial distribution of water quality in the lake should be clearly understood. The objectives of this study are to show a methodology and to develop a simulation system to calculate COD distribution in Lake Biwa taking internal COD production into consideration. This study also aims to examine transition of COD in the lake using the simulation system. In the simulation system, runoff loads of COD from the Lake Biwa basin are calculated by Macro Model for each tributary. The external COD concentration in 233 inshore meshes of the Lake Biwa water surface was calculated using the runoff loads. The internal COD was calculated using relationships among limiting nutrients, chlorophyll-a and COD. Then, the spatial distribution of water quality in Lake Biwa was calculated both for the external and internal COD by spline technique. Simulations using the system were implemented for 1986-1998, and a clear difference in characteristics between a drought year and a flood year was shown. In the result, it was shown that the simulation system developed here was available to calculate COD distribution in Lake Biwa, and that it had the possibility to explain the recent phenomenon of COD increase in the lake.     

Evaluation of nutrient loads from a mountain forest including storm runoff loads.

Water quality and flow rates at a weir installed on the end of Aburahi-S Experimental Watershed (3.34 ha) were measured once a week from 2001 to 2003 and in appropriate intervals from 30 min to 6 h during five storm runoff events caused by each rainfall from 8 mm to 417 mm. The average annual loads of total nitrogen (TN) and total phosphorus (TP) were calculated to be 19.0 and 0.339 kg ha(-1) y(-1) from the periodical data by using the integration interval-loads method (ILM), which did not properly account for storm runoff loads. Three types of L(Q) equations (L = aQ(b)) were derived from correlations between loading rates L and flow rates Q obtained from the periodic observation and from storm runoff observation. L(Q) equation method (LQM), which was derived from the storm runoff observation and allowed for the hysteresis of discharge of materials, gave 9.68 and 0.159 kg ha(-1) y(-1), respectively, by substitution of the sequential hourly data of flow rates. L(R) equation (L = c(R - r)d) was derived from the correlations between the loads and the effective rainfall depth (R - r) measured during the storm runoff events, and L(R) equation method (LRM) calculated 9.83 +/- 1.68 and 0.175 +/- 0.0761 kg ha(-1) y(-1), respectively, by using the rainfall data for the past 16 years. The atmospheric input-fluxes of TN and TP were 16.5 and 0.791 kg ha(-1) y(-1).     

南四湖水质空间分布特征分析与改善效果评估

根据南四湖2006年、2007年、2010年和2011年4次90个采样点的水质空间分布监测数据,采用Surfer 8.0软件绘制南四湖水质空间分布等值线图,进行南四湖及分湖区水质指标的综合比较分析和平均综合污染指数的计算与污染控制效果评估。结果表明:南四湖COD、NH3-N、TP、TN和CODMn等指标的空间分布具有北高南低的非均一性特点;2010—2011年比2006—2007年枯水期各水质指标的平均浓度下降率为38.3%,整体提高了1～2个水质类别;按GB 3838—2002《地表水环境质量标准》中Ⅲ类标准相应的平均综合污染指数进行评价,达标和基本达标湖区的比例达到63.3%;2010—2011年枯水期南四湖主要污染物分担率由大到小排序依次为TP、COD、TN、CODMn、NH3-N;水质平均综合污染指数与电导率存在很好的相关性和北高南低的污染特点,说明南四湖水污染物仍然以外源排放为主。     

Monitor-based evaluation of pollutant load from urban stormwater runoff in Beijing.

As a major pollutant source to urban receiving waters, the non-point source pollution from urban runoff needs to be well studied and effectively controlled. Based on monitoring data from urban runoff pollutant sources, this article describes a systematic estimation of total pollutant loads from the urban areas of Beijing. A numerical model was developed to quantify main pollutant loads of urban runoff in Beijing. A sub-procedure is involved in this method, in which the flush process influences both the quantity and quality of stormwater runoff. A statistics-based method was applied in computing the annual pollutant load as an output of the runoff. The proportions of pollutant from point-source and non-point sources were compared. This provides a scientific basis for proper environmental input assessment of urban stormwater pollution to receiving waters, improvement of infrastructure performance, implementation of urban stormwater management, and utilization of stormwater.     

鄱阳湖流域径流、泥沙及水质变化研究

鄱阳湖是中国第一大淡水湖泊,在调节长江径流、维护生态平衡、保持生物多样性及发展区域生态经济等方面有着举足轻重的作用.近年来,随着鄱阳湖流域人类活动及水文情势的发展变化,鄱阳湖水环境发生相应变化.2000年以后,特别是2004年以后,鄱阳湖流域由于城市化进程加速,湖区采砂,航道整治,以及水文循环处于干旱期或水资源消耗加剧等因素的综合影响,鄱阳湖典型站的水质指标较以前变化更为频繁和剧烈.然而,相对于其他封闭型的湖泊如巢湖、太湖等,鄱阳湖污染物的积累现象非常微弱.     

流域年径流量组合预测方法研究与应用

本文介绍了组合预测模型的原理,并以周期叠加外推法、平稳时间序外推法和灰色预测为子预测模型建立时变权最小方差组合预测模型。实例计算结果表明,时变权最小方差组合预测模型的预测精度优于3个子预测模型。组合预测模型理论依据充分,既可应用于流域年径流量的预测,又可推广到其他水文要素的预测。     

Using a GIS transfer model to evaluate pollutant loads in the Lake Kinneret watershed, Israel.

Lake Kinneret (Sea of Galilee) is the only large surface water body in Israel, encompassing an area of 167 km2 and supplying some 30% of the country's fresh water. Pollution from anthropogenic sources and water abstraction for domestic and agricultural uses has long been threatening the water quality of the lake. Point-source pollution in the watershed has decreased drastically with the development of wastewater treatment. However, diffuse pollution from agricultural activities is still an unresolved issue. In this paper we present an application of AVGWLF (a GIS-based watershed load model) to the Lake Kinneret watershed. The model allows one to simulate daily stream flows and monthly sediment, nitrogen, and phosphorus loads discharged to the lake from the surrounding watershed. Results from simulations yield a satisfactory correspondence between simulated and measured daily water volume. Partition by source of total phosphorus delivered to the lake in the period of 2000-04 confirms the reduction in point source nutrient contribution due to improvement of wastewater treatment facilities in the area. Future management should focus on reduction of nutrients originating from septic systems (point sources) and pasture and cropland areas (diffuse sources). Results from simulations will enable watershed managers to prioritize effective management alternatives for protecting the water quality in the lake.     

鄱阳湖流域农村水环境污染防治对策研究

农村水环境是鄱阳湖流域水环境的重要组成部分.通过分析鄱阳湖流域农村水环境现状及存在问题,并针对问题提出农村水环境污染防治对策,重点包括了人工湿地、沟塘和生态沟渠工程措施.在工程措施的基础上,提出管理措施,为保障鄱阳湖＂一湖清水下泄＂提供支撑.     

北京市妫水湖的叶绿素a及其水质关系分析

通过对妫水湖水环境中的叶绿素a的测定并同时分析其水质,结果表明,妫水湖水域的叶绿素a的含量呈明显的时空变化特征,其中7月和10月含量高于6月、8月和9月,另外,1号、2号和3号位置的含量明显高于4号、5号和6号位置.叶绿素a含量与环境因子,如水中总氮、总磷、BOD5、CODMn有关.妫水湖叶绿素a含量变化多在(5～40)mg/m3范围内,说明妫水湖水体处于富营养状态.     

北京市城市道路雨水径流水质特性研究

对北京市城市道路雨水径流水质监测结果表明,雨水径流水质恶劣,主要污染物指标与生活污水相近,且初期雨水径流水质更劣.道路雨水径流SS与其他污染物的相关性研究表明,径流污染物多数存在于SS中,可通过沉淀去除SS,进而提高雨水水质.雨水静置沉淀试验结果表明,北京市道路雨水SS的沉淀性能良好,经过充分沉淀,雨水上清液能够达到<城市污水再生利用城市杂用水水质>(GB/T 18920-2002)对城市绿化用水的要求,且雨水储存14 d不会发生缺氧变质现象.     

Synthetic- and bio-polymer use for runoff water quality management in irrigated agriculture.

Low concentrations of synthetic- or bio-polymers in irrigation water can nearly eliminate sediment, N, ortho- and total-P, DOM, pesticides, micro-organisms, and weed seed from runoff. These environmentally safe polymers are employed in various sensitive uses including food processing, animal feeds, and potable water purification. The most common synthetic polymer is anionic, high purity polyacrylamide (PAM), which typically provides 70-90% contaminant elimination. Excellent results are achieved adding only 10 ppm PAM to irrigation water, applying 1-2 kg ha(-1) per irrigation, costing 4 dollars - 12 dollars kg(-1). Biopolymers are less effective. Using twice or higher concentrations, existing biopolymers are approximately 60% effective as PAM, at 2-3 times the cost. A half million ha of US irrigated land use PAM for erosion control and runoff protection. The practice is spreading rapidly in the US and worldwide. Interest in development of biopolymer surrogates for PAM is high. If the supply of cheap natural gas (raw material for PAM synthesis) diminishes, industries may seek alternative polymers. Also "green" perceptions and preferences favor biopolymers for certain applications.     

配水管网中水质变化规律及主要影响因素分析

安全输配是饮用水水质保障的关键。在对中国南方 S 市配水管网水质大量调查的基础上,分析了余氯、浊度、铁、三卤甲烷、卤乙酸、AOC 等主要水质指标在管网中的变化规律,发现余氯沿管线逐渐降低,浊度和铁基本沿管线逐渐增加,其主要影响因素有管道属性、温度及水力条件等;三卤甲烷在管网中表现出增加的趋势,而卤乙酸则在管网中表现出降低的趋势,其主要影响因素有余氯浓度、水质条件、温度条件及水力条件等;供水系统中 AOC 以 AOC-P17为主要组分,沿供水系统有逐渐增加的趋势,其浓度、组成以及在管网中的变化规律呈现明显的季节性。     

Sensitivity to experimental data of pollutant site mean concentration in stormwater runoff.

Urban wet weather discharges are known to be a great source of pollutants for receiving waters, which protection requires the estimation of long-term discharged pollutant loads. Pollutant loads can be estimated by multiplying a site mean concentration (SMC) by the total runoff volume during a given period of time. The estimation of the SMC value as a weighted mean value with event runoff volumes as weights is affected by uncertainties due to the variability of event mean concentrations and to the number of events used. This study carried out on 13 catchments gives orders of magnitude of these uncertainties and shows the limitations of usual practices using few measured events. The results obtained show that it is not possible to propose a standard minimal number of events to be measured on any catchment in order to evaluate the SMC value with a given uncertainty.     

辽河流域河流水质综合评价

本文以辽河流域为例,将水质风险次序权重与组合准则权重相耦合构建评价模型,运用该模型计算评价了多种次序权重和河流水质等级。结果表明:风险水平α=1的条件下,国标法划分的监测点水质类别与该方法保持较好的一致性,对于河流水质的评价该方法符合实用性和可行性要求;石油类、总磷、氨氮、总有机碳等因子对流域水质的影响显著;入海口水质受地理位置制约,总体处于较差水平;水环境污染来源以工业废水、城市和农业污水为主。该耦合评价方法可为流域水环境保护和水质治理提供数据支撑。     

辽河流域地表水水质达标评价及水质变化分析

本文根据多年地表水水质监测资料,系统地对辽河流域地表水进行了水质达标评价和水质变化趋势分析,并确定了严重污染河流名单.结果表明:辽河流域地表水水质污染以有机污染为主,点源污染重于面源污染.水质达标率不高,地表水污染有上升的趋势.     

气候变化对半干旱区流域径流影响的分析研究

水资源短缺是制约半干旱区区域经济发展的主要因素。由于气候变化和人类活动改造自然能力的不断提高,导致水资源循环在时空分布上发生了很大变化。在过去50年,地球表面温度平均每10年上升0．13℃。     

Impact of agricultural practices and river catchment characteristics on river and bathing water quality.

The objective was to investigate the potential risk of faecal indicator organism (FIO) bacteriological contamination of river catchments and coastal bathing waters from farm management practices and to develop practices to reduce the risk. A risk assessment on 117 farms was carried out in two river catchments in south-west Scotland. Manure storage facilities, farming practices, field conditions and catchment characteristics were assessed. River samples at 33 locations were regularly taken and analysed for FIOs. Available manure storage capacity and farm management practices are inadequate on a high proportion of farms and FIO contamination of watercourses was likely the result of effluent transported into watercourses due to non-collection or poor containment. In addition, surface run-off or leaching following land application of manure or intensive stocking in adverse conditions was a high risk on up to 50% of farms. The concentrations of FIOs in the streams of two sub-catchments with high livestock intensity was 4 to 8 times higher compared to the two sub-catchments which had a low livestock intensity. The majority of potential risks of agricultural pollution to watercourses may be eliminated through improved manure and dirty water management, forward planning of manure spreading activities and improved operational procedures.     

供水管网水质监测点综合优化布置研究

监测供水管网的水质状况,提高供水水质的安全性是一个复杂而又亟待解决的课题.在基于污染预警监测的优化监测点布置中,加入节点水龄数据集约束,将两个目标综合优化,实现了常规监测意义下的污染灾害预警监控.通过小规模管网实际验证,证明了该方法的合理性和有效性.