Using precise data sets on farming and pesticide properties to verify a diffuse pollution hydrological model for predicting pesticide concentration.

Verification of a diffuse pollution model involves comparing results actually observed with those predicted by precise model inputs. Acquisition of precise model inputs is, however, problematic. In particular, when the target catchment is large and substantial estimation uncertainty exists, not only model verification but also prediction is difficult. Therefore, in this study, rice-farming data were collected for all paddy fields from all farmers in a catchment and pesticide adsorption and degradation rates in paddy field soil samples were measured to obtain precise model inputs. The model inputs successfully verified the model's capability to predict pesticide concentrations in river water. Sensitivity analyses of the model inputs elucidated the processes significantly affecting pesticide runoff from rice farms. Pesticide adsorption and degradation rates of the soil did not significantly affect pesticide concentrations, although pesticide discharge to river water accounted for less than 50% of the total quantity of pesticide applied to fields, possibly owing to pesticide adsorption and degradation. The timing of increases in pesticide concentrations in river water was affected mostly by the farming schedule, including the time of pesticide application and irrigation, and secondarily by rainfall events.     

Simultaneous estimation of model parameters and diffuse pollution sources for river water quality modeling.

Diffuse pollution sources along a stream reach are very difficult to both monitor and estimate. In this paper, a systematic method using an optimal estimation algorithm is presented for simultaneous estimation of diffuse pollution and model parameters in a stream water quality model. It was applied with the QUAL2E model to the South Han River in South Korea for optimal estimation of kinetic constants and diffuse loads along the river. Initial calibration results for kinetic constants selected from a sensitivity analysis reveal that diffuse source inputs for nitrogen and phosphorus are essential to satisfy the system mass balance. Diffuse loads for total nitrogen and total phosphorus were estimated by solving the expanded inverse problem. Comparison of kinetic constants estimated simultaneously with diffuse sources to those estimated without diffuse loads, suggests that diffuse sources must be included in the optimization not only for its own estimation but also for adequate estimation of the model parameters. Application of the optimization method to river water quality modeling is discussed in terms of the sensitivity coefficient matrix structure.     

省界水资源监测站盱眙水文站流量测验精简分析

根据省界水资源监测站盱眙水文站现有测验条件和工作任务,以缩短流量测验历时、减轻工作强度、保证测验精度、提高测报质量为指导思想,在2015年流量测验资料基础上,通过对测速垂线和测点的精简分析,合理优化测验方案,达到了"高效准确"的水文测报新要求,为其他水文站开展流量测验精简分析工作提供借鉴。     

淮干小柳巷水文站水位流量关系单值化初步分析

本文用落差指数法分段计算落差,对小柳巷水文站水住流量关系单值化作初步分析,取得了较好的效果,为简化测验、整编和水文巡测提供技术支持。     

Sensitivity analysis of non-point sources in a water quality model applied to a dammed low-flow-reach river.

Downstream of Capim Branco I hydroelectric dam (Minas Gerais state, Brazil), there is the need of keeping a minimum flow of 7 m3/s. This low flow reach (LFR) has a length of 9 km. In order to raise the water level in the low flow reach, the construction of intermediate dikes along the river bed was decided. The LFR has a tributary that receives the discharge of treated wastewater. As part of this study, water quality of the low-flow reach was modelled, in order to gain insight into its possible behaviour under different scenarios (without and with intermediate dikes). QUAL2E equations were implemented in FORTRAN code. The model takes into account point-source pollution and diffuse pollution. Uncertainty analysis was performed, presenting probabilistic results and allowing identification of the more important coefficients in the LFR water-quality model. The simulated results indicate, in general, very good conditions for most of the water quality parameters The variables of more influence found in the sensitivity analysis were the conversion coefficients (without and with dikes), the initial conditions in the reach (without dikes), the non-point incremental contributions (without dikes) and the hydraulic characteristics of the reach (with dikes).     

Dynamic actor network analysis for diffuse pollution in the province of North-Holland.

Diffuse pollution problems involve numerous different organizations and this requires decision makers to involve different actors if they want to develop policies that have a chance of being implemented effectively. A first step in such interactive policy development would be to gain an overview of the different actors involved in diffuse pollution problems, as well as their views on the problem, their interests and their means to influence policy development and implementation. Dynamic Actor Network Analysis (DANA) offers a method that helps analysts in providing such an overview, and the use of this method is explored through its application to a case in the Dutch province of North Holland. The described case specifically focuses on the use of herbicides in public space and involves actors from regional water management authorities, municipalities and private sector users. An important finding is that there is an imbalance in the perceptions of actors that needs to be addressed by water management authorities. The paper concludes that DANA is a promising tool for offering new and useful insights to decision makers, although more practical experience is needed to better assess the utility of this analysis tool.     

倾斜岸河库水面污染源下浓度分布的理论分析

从保守物质横向和垂向扩散系数不相等的静止水体中瞬时线源二维扩散的解析解人手,分析推导出半无限水面瞬时污染源下二维扩散的浓度计算公式。在顺直倾斜岸坡大宽度深水情况下,借助于横向和垂向扩散系数不相等的角形域映射原理,进而推导出倾斜岸水面瞬时污染源下角形域中二维扩散浓度分布的理论公式。在简化条件下该理论公式与可对比理论解完全一致。结果分析与讨论表明:角形域倾角对污染物的浓度分布影响较大;角形域内浓度分布具有倾角参数n(180/)为奇数和偶数不同的双重特性;计算点距离岸坡顶点越近倾斜岸坡对浓度分布的影响越大;横坐标越大影响越小;水深越大影响也越小。该理论公式可为河库水质监测布点与数据的归纳分析、水质模型的验证和污染混合区浓度估算提供有力的工具。     

南宁市主要入河污染源对饮用水源污染分析

通过对近年来影响南宁市重点饮用水水源地的主要入河污染源排污状况进行分析,分析了入河排污沟排污趋势,并考虑在南宁市政府出台相应的水资源保护工程项目实施后,对水源地入河污染源未来排污状况的影响进行综合分析,从而预测南宁市重点饮用水水源地入河污染物未来变化趋势,为南宁市水行政部门保护和管理水资源提供参考.     

Waste load allocation for water quality management of a heavily polluted river using linear programming.

A waste load allocation model using linear programming has been developed for economic water quality management. A modified Qual2e model was used for water quality calculations and transfer coefficients were derived from the calculated water quality. This allocation model was applied to the heavily polluted Gyungan River, located in South Korea. For water quality management of the river, two scenarios were proposed. Scenario 1 proposed to minimise the total waste load reduction in the river basin. Scenario 2 proposed to minimise waste load reduction considering regional equity. Waste loads, which have to be reduced at each sub-basin and WWTP, were determined to meet the water quality goal of the river. Application results of the allocation model indicate that advanced treatment is required for most of the existing WWTPs in the river basin and construction of new WWTPs and capacity expansion of existing plants are necessary. Distribution characteristics of pollution sources and pollutant loads in the river basin was analysed using Arc/View GIS.     

Comprehensive management of chemical substances in a water environment using PRTR data.

The annual quantity of discharge of 354 chemical substances from each business has been released based on PRTR law in Japan since 2003. MLIT and municipalities should be responsible for managing chemical risk in public water bodies through communication with stakeholders, such as the public and businesses. However, it is economically difficult to measure the discharge loads and behaviour of all chemical substances and reveal which substances should be particularly managed in each basin. NILIM has begun studies on survey methods to understand the discharge and behaviour of chemical substances in each basin based on PRTR information, and to conduct risk management of chemical substances in cooperation with stakeholders such as the public and businesses. We selected 30 chemical substances, such as those listed or nominated in environmental criteria and endocrine disrupters, collected the volume of discharge of chemical substances from public and industrial wastewater treatment plants using PRTR information, and surveyed their behaviour in the river in the model area. As a result, the discharge of 12 chemical substances were reported in PRTR, and 17 substances were detected in the river. Some inorganic compounds were detected intensively near discharge sites reported in the PRTR. But some organic compounds and endocrine disrupters, such as oestrone, were detected although their discharge was not reported in the model area in the PRTR. It suggested that PRTR information is useful to identify hot spots, but further study is needed to understand the discharge of chemical substances from small businesses, farmland and houses.     

Continuous monitoring in sewer networks an approach for quantification of pollution loads from CSOs into surface water bodies.

Different approaches for quantification of pollution loads discharged from combined sewer networks into surface water bodies have been observed over the last few years and decades, but a large number of unresolved problems still remain. Many monitoring campaigns have been based on manual or automated spot sampling - with the long known limitations of this method such as sampling errors and errors due to sample conservation, transport and preparation. On the other hand, only recently have sensors became available which are suitable for continuous application in sewer networks. A large number of practical problems still have to be solved before continuous monitoring in sewer networks will be successful. Additionally, most of the applicable sensors are based on surrogate methods which results in a considerable effort for reference measurements for sensor calibration. Finally, it has to be considered that, depending on the sewer network topography, deposition and remobilisation of pollutants varies considerably, which limits the generality of monitoring results and, subsequently, their applicability as a base for the design of storm water tanks or combined sewer overflows (CSO). A monitoring station for continuous monitoring of load discharges from a CSO has been installed and operated for more than one year. The design and equipment of the measurement station, operational experiences and results are given in this paper.     

近10年来洞庭湖区水面面积变化遥感监测分析

以Terra/MODIS 8d合成的250m地表反射率数据产品MOD09Q1(MODIS Terra Surface Reflectance 8-Day L3 Global 250m)为主要数据源,采用多源信息水面提取的方法对2000年3月—2008年12月间洞庭湖区水面面积的变化特征和趋势进行了监测分析。分析结果显示:(1)洞庭湖区水面变化的季节性特征显著,其中枯水期11月—次年4月份间的湖区水面相对较小,基本在500km2左右,而洪水期5—10月份的水面则相对较大,尤其每年的7—9月份最大,维持在2000km2左右,两者几乎相差了4倍;(2)受气候变化与三峡工程初期运行等因素的共同影响,洞庭湖区水域面积总体上呈现出一定程度的下降趋势;(3)通过流域年降水量变化分析和三峡水库蓄水运行前后松滋、太平和藕池三口年径流量变化对比,发现流域内降水带来的入湖水量偏少是近年来洞庭湖区水面面积减小的主要驱动因子;(4)近年来9、10月份洞庭湖流域降水减少与三峡水库汛末蓄水同期,将共同造就最终入湖水量锐减,加重湖区夏秋连旱程度,进而诱发系列生态安全问题。     

近10年来洞庭湖区水面面积变化遥感监测分析

以Terra/MODIS 8d合成的250m地表反射率数据产品MOD09Q1(MODIS Terra Surface Reflectance 8-Day L3 Global 250m)为主要数据源,采用多源信息水面提取的方法对2000年3月-2008年12月间洞庭湖区水面面积的变化特征和趋势进行了监测分析.分析结果显示:(1)洞庭湖区水面变化的季节性特征显著,其中枯水期11月一次年4月份间的湖区水面相对较小,基本在500km2左右,而洪水期5-10月份的水面则相对较大,尤其每年的7-9月份最大,维持在2 000km2左右,两者几乎相差了4倍;(2)受气候变化与三峡工程初期运行等因素的共同影响,洞庭湖区水域面积总体上呈现出一定程度的下降趋势;(3)通过流域年降水量变化分析和三峡水库蓄水运行前后松滋、太平和藕池三口年径流量变化对比,发现流域内降水带来的入湖水量偏少是近年来洞庭湖区水面面积减小的主要驱动因子;(4)近年来9、10月份洞庭湖流域降水减少与三峡水库汛末蓄水同期,将共同造就最终入湖水量锐减,加重湖区夏秋连旱程度,进而诱发系列生态安全问题.     

Measures for structural improvement with regard to the good status of water bodies--estimation of expenditure for a river basin in Germany.

To achieve the objective of "good chemical and ecological status" in water bodies as stipulated by the European Water Framework Directive (WFD) in particular, a package of measures geared to improving the water bodies' hydromorphology will be required. These upgrading measures can, to some extent, also be seen as an alternative to still more advanced measures in the field of wastewater treatment and stormwater treatment in the context of status improvement in water bodies. On account of the very high level of wastewater and stormwater treatment already achieved, additional efforts in this specific area would, as experience has shown, not only be extremely costly, but produce just moderate if not minor results. In an estimate of the funding required to achieve "good status" by hydromorphological change, undertaken for the Ruhr River Basin (German state of North Rhine-Westphalia), it was found that costs would be in the range of [symbol: see text] 200 million to [symbol: see text] 1 billion. This translates into inhabitant-specific costs of [symbol: see text] 100 to [symbol: see text] 500 per capita. All measures are to be put into practice within the scope of an integrated water body development concept, optimised with regard to space and time.     

Multi-variable sensitivity and identifiability analysis for a complex environmental model in view of integrated water quantity and water quality modeling

Environmental models are often over-parameterized. A sensitivity analysis can identify influential model parameters for, e.g. the parameter estimation process, model development, research prioritization and so on. This paper presents the results of an extensive study of the Latin-Hypercube-One-factor-At-a-Time (LH-OAT) procedure applied to the Soil and Water Assessment Tool (SWAT). The LH-OAT is a sensitivity analysis method that can be categorized as a screening method. The results of the sensitivity analyses for all output variables indicate that the SWAT model of the river Kleine Nete is mainly sensitive to flow related parameters. Rarely, water quality parameters get a high priority ranking. It is observed that the number of intervals used for the Latin-Hypercube sampling should be sufficiently high to achieve converged parameter rankings. Additionally, it is noted that the LH-OAT method can enhance the understanding of the model, e.g. on the use of water quality input data.     

山区梯田集成配套小型水工程的和谐性分析模型

针对山区梯田集成配套小型集引蓄排水工程的建设和运行使用,对因与工程区自然、人文社会经济环境不和谐,导致效益低下,土地、资金大量浪费,工程难以实现其期望价值等问题进行了分析.按工程与自然环境、人文社会相互耦合这一广义的复合系统观念,建立了一与梯田集成配套的小型水工程和谐性的分析模型,并在贵州毕节地区的实际工程中进行了应用.     

Application of HACCP principles as a management tool for monitoring and controlling microbiological hazards in water treatment facilities.

HACCP (hazard analysis and critical control points) principles were applied to evaluate the effectiveness of two water treatment facilities to continually produce potable water free of microbiological health hazards. This paper reports a hazard analyses protocol (microbiological hazards based on faecal coliforms (FC) and turbidity (TBY) as indicators) for critical control points (CCPs) within each facility. The CCPs were raw resource water, sedimentation, filtration and chlorine-disinfection. The aim was to determine the effectiveness of each CCP to remove the indicators from the water under treatment. Arbitrary critical performance limit targets (CPLTs) were set up for each CCP to determine to what extent each contributed to effective removal and to predict what the effect would be if any of the CCPs should fail. Health-related water quality guideline limits for expected health effects were applied and compliance measured at the 90th percentile. The raw resource river water used at both treatment facilities complied with raw resource water extraction CPLTs. The treated potable water complied with health-related drinking water guidelines. Sedimentation removed the largest proportion of the indicators from the raw water, but showed failure potential that could overload the consequent system. Filtration effectiveness at both treatment facilities showed potential to break down the overall effectiveness of the entire treatment facility, since the filter systems failed to meet their respective CPLTs. This left the disinfection phase to remove the remaining portion of indicators. Faecal coliforms appeared to be completely removed from post-chlorination samples. This indicated that both chlorine disinfection phases were 100% effective in meeting their disinfection CPLTs, despite having to "clean up" the indicator organisms that spilt over from the upstream CCPs. This, nevertheless, implied a risk of unsafe water release into distribution. CCPs at these treatment facilities had some difficulties in reducing the health-related risks to meet their respective CPLTs. Applying a HACCP programme would minimise the risk of contaminated water distribution in cases of system component failure.     

裂隙岩体渗流耦合数值分析方法及其工程应用

针对岩体中主干裂隙和网络状裂隙提出了耦合渗流数值模型模拟分析岩体地下水三维渗流的方法。使用离散介质渗流模型描述岩体主干裂隙中的水运动，使用连续介质渗流模型描述网络状裂隙中水运动。连续介质充满整个研究域，离散介质按主干裂隙的实际空间分布嵌入连续介质中，并依据裂隙壁水力条件耦合两者。该方法逐个计算主干裂隙的渗流，充分体现主干裂隙的特殊水力作用；同时又避免了逐个计算网络状裂隙中的渗流所带来的困难，可以在较大尺度上分析渗流，便于工程应用。理论例子显示它能比较客观地反映裂隙岩体的渗流特性。该方法被应用到乌江构皮滩水利枢纽岩体渗流的分析中。     

Aeration control for simultaneous nitrification-denitrification in a biological aerated filter using internal model approach.

Experience has shown that simultaneous nitrification/denitrification in a biological aerated filter is possible. However these systems react very sensitively to the aeration control strategies applied. Poorly adapted control strategies induce a strong decrease in treatment efficiency. A new control strategy for simultaneous N/DN is developed. The strategy proposed makes use of ammonia measurements and the inlet and outlet: a Feedback/Feedforward block. Passing by a calculation of the load to be eliminated, an estimation of the air flow velocity to be applied is carried out dynamically. A retroactive loop corrects this prediction in order to reach exactly the desired set point. This control approach has been implemented and tested at pilot plant scale for a period of 18 months. The pilot plant consists of two coupled BAF cells, reflecting closely industrial scale situations. Comparative studies reveal clearly the improved performance of the developed FF/FB control strategy compared to classical controllers. The benefits include 5% increase in nitrogen removal performance and a reduction of 15 to 20% in air requirement, offering a rapid return of investment costs.     

Simulation supported scenario analysis for water resources planning: a case study in northern Italy.

The work presents the results of a comprehensive modelling study of surface and groundwater resources in the Muzza-Bassa Lodigiana irrigation district, in Northern Italy. It assesses the impact of changes in land use and irrigation water availability on the distribution of crop water consumption in space and time, as well as on the groundwater resources. A distributed, integrated surface water-groundwater simulation system was implemented and applied to the study area. The system is based on the coupling of a conceptual vadose zone model with the groundwater model MODFLOW. To assess the impact of land use and irrigation water availability on water deficit for crops as well as on groundwater system in the area, a number of management scenarios were identified and compared with a base scenario, reflecting the present conditions. Changes in land use may alter significantly both total crop water requirement and aquifer recharge. Water supply is sufficient to meet demand under present conditions and, from the crop water use viewpoint, a reduction of water availability has a positive effect on the overall irrigation system efficiency; however, evapotranspiration deficit increases, concentrated in July and August, when it may be critical for maize crops.