国外跨界水污染治理的经验与启示

介绍莱茵河、五大湖、多瑙河等跨国界河流以及美国田纳西河、英国泰晤士河、意大利波河等跨省界河流的水污染治理机制,分析国外跨界水污染治理的发展趋势:从整体上把握水污染治理,建立一种跨界综合管理模式;进行以流域为单位的水资源综合规划,注重流域水环境容量与经济发展的相互关系;设立流域水资源管理协调与咨询机构,鼓励公众参与管理;水资源开发利用市场化。国外跨界水污染治理从4方面为我国的水污染治理提供借鉴:①水污染治理机构组成的多元化;②水资源管理体制的多层次;③消费者协会参与水资源管理;④公众参与水资源保护。建议中国的跨界水污染治理可从以下几方面着手:①建立统一管理、垂直领导的流域管理体制;②加快流域立法进程;③流域投资运行机制市场化;④建立流域企业化管理体制;⑤优化流域管理机构内部结构。     

淮河流域历史覆被变化及其对水文过程的影响

以淮河流域蚌埠集水区为研究区域,利用淮河流域1700、1800和2000年3种历史覆被情景,结合陆面水文耦合模型(CLHM)定量评价了流域土地利用/覆被变化的水文效应,并分析了流域径流与主要覆被类型变化方式的定量关系。结果表明:CLHM模型可以较好地模拟淮河流域的流量过程,在研究区具有较好地适用性;三期覆被情景下主要覆被类型变化为林地转变为耕地或草地以及草地转变为耕地,此种变化导致流域总蒸发量减少了6.5%,流域出口研究期平均径流量增加了6.1%;极端覆被情况下,年均蒸发量由多到少依次为林地、草地和耕地;林地对流域径流过程的影响主要体现在洪峰上,相对于耕地,林地具有削减洪峰的作用;通过分析覆被类型变化与流域多年平均径流的相关关系,林地转变为草地以及林地转变为耕地是近400年来影响淮河流域水文过程及水资源分配的主要覆被变化因子。因此,合理规划土地利用格局对流域水资源高效利用具有重要意义。     

森林覆盖率变化对流域洪水特性影响的数值模拟

为研究森林覆盖率变化对洪水特性的影响，建立小溪流域的分布式水文模型，通过实测水文资料对模型重要参数进行率定和验证，并对其适用性进行评价。选取7日同次降雨序列，利用率定并验证后的数学模型对森林覆盖率从0到100%共11组工况的流域洪水过程进行模拟。结果表明，森林覆盖率的变化对小溪流域洪水特性产生一定影响，森林覆盖率越大，影响效果越明显；相比无森林覆盖条件，森林覆盖率达到最大时减小洪峰流量约13.2%，延缓洪峰到达时间约4 h，延长洪水历时约13 h；当森林覆盖率低于40%时，森林对洪峰的削减作用非常有限；当森林覆盖率大于40%时，森林覆盖率平均每增长10%，可削减洪峰流量约2%；并且随着森林覆盖率增长，洪水过程形态呈现从单峰到双峰的变化特点。     

State-of-the-art review of transboundary water governance in the Euphrates–Tigris river basin

This article reviews the state of the art of transboundary water governance in the Euphrates–Tigris river basin, which is characterized by both political confrontation and cooperative institutional development. First, research on the physical characteristics of the basin is presented, with references to the literature on large-scale water development projects that underpin transboundary water interactions. Then, contending approaches to transboundary water governance are discussed, with specific references to the evolution of institutions. Finally, bearing in mind that transboundary water governance in the basin occurs in volatile political circumstances, current issues such as control of the water infrastructure by non-state violent actors and protection of water during armed conflict are scrutinized.     

Accounting of Transboundary Ecocompensation Standards Based on Water Quantity Allocation and Water Quality Control Targets

In China, under the premise that the water quantity allocation and water quality control targets for transboundary rivers have been determined, ecocompensation between upstream and downstream areas is urgently needed in management practice when targets cannot be met in the transboundary section. A dynamic accounting method for ecocompensation standards needs to be established at the scientific level. However, the accounting method of the existing ecocompensation standards is not sufficient. The purpose of this study is to propose a transboundary compensation standard accounting method based on water quantity allocation and water quality control targets and to establish ecocompensation standard accounting formulas for the Shaying River watershed. The accounting process is as follows: the water quantity compensation standard in different water quantity scenarios is calculated from the perspective of the water resource value. By using the comprehensive pollution index method, the water quality compensation standard is calculated in different water quality scenarios, and the ecocompensation standard calculation formulas for watersheds are determined. As an application, 27 types of ecocompensation standard formulas for the Shaying River watershed were determined for 3 hydrological frequencies (50%, 75% and 95%), 3 water quantity scenarios (equal-quantity, excess-quantity and reduced-quantity discharging) and 3 water quality levels (equal-quality, inferior-quality and better-quality discharging). The results not only provide a compensation standard for the Shaying River but also provide a reference for the calculation of ecocompensation standards for other transboundary rivers in China with definite water quantity and water quality management objectives.

     

Contrasting water securities: the Mexican state facing downstream stakeholders in the Suchiate transboundary river basin

Based on extensive interviews, fieldwork and archival research conducted in southern Mexico, this article explores and analyzes contrasting water-security perspectives of diverse stakeholders in flood-prone portions of the transboundary Suchiate River basin. Complexities of transboundary water issues along an international river that is also a border produce power relationships between the Mexican state and inhabitants, plus historical tensions with riparian neighbour Guatemala, and diverse meanings among local stakeholders. The Mexican state conceptualizes water security as a conventional national-security issue, whereas the basin’s rural inhabitants consider it a matter of human security, albeit in diverse ways that provoke internal conflicts.     

Future bottlenecks in international river basins: where transboundary institutions,population growth and hydrological variability intersect

Using global data, this article examines the nexus of transboundary flood events and future social vulnerability. Which international river basins are forecast to experience an increase in both hydrological variability and population in the future, but currently lack institutional provisions to deal with these shared events? Concentrations of elevated risk are found in several basins in Central Asia, Central America and Central Africa. The article ends by highlighting transboundary basins that merit further investigation and possibly additional institution building to reduce urban flood risk.     

International river basin organizations: variation,options and insights

Permanent international river basin organizations (IRBOs) come in many shapes and sizes, ranging from those which are mainly facilitative in nature to those empowered to act on their own. Although differences in IRBO types may have important impacts on transboundary water resources management, systematic analysis of variation in their structure and responsibilities is scant. This paper synthesizes and applies a typology to determine the structural composition, abundance, spatial distribution, scale and in-basin configurations of the different forms of IRBOs. The results provide a set of options for future IRBOs, and serve to ground-truth and nuance theoretical divisions between different types of organizations in transboundary basins.     

跨界河流安全的风险因子识别及风险控制研究

为实现跨界河流地区国家边境安全、经济社会可持续发展、水生态环境持续良好、水资源可持续利用,基于跨界河流的特点,针对目前我国跨界河流安全研究偏少、风险影响因素缺乏系统分析等问题,综合采用专家调查法、幕景分析法、故障树分析等方法,首次识别并结构化分析了影响跨界河流安全的水文、工程、政治外交、经济社会、法律及其他方面的六类风险因子。在此基础上以提高风险可接受度为目的,研究提出了跨界河流安全风险类型、风险控制总体思路策略以及风险控制方法措施。在跨界河流安全风险识别的基础上,应针对其中的可控风险,从工程措施和非工程措施方面实施风险控制。研究成果为我国跨界河流安全风险分析提供技术支撑并已成功应用于实际工作,对制定跨界河流安全保障总体思路和对策措施具有重要作用。     

Simulating system‐wide effects of reducing irrigation withdrawals in a disputed river basin

Stakeholders in river systems often target larger upstream water consumers as an intuitive solution for increasing flows for downstream ecological needs. Within regulated river systems, simplistic panaceas may have unexpected and unintended results at a watershed level. The Apalachicola–Chattahoochee–Flint River Basin is a large watershed in the south‐eastern United States whose management has been the source of conflict for several decades. This paper tests the hypothesis of whether a reduction in consumptive losses to Flint River flows through the large‐scale implementation of water‐saving agricultural irrigation technologies and practices will have a positive effect on downstream ecosystem water requirements in the Apalachicola River. An existing integrated reservoir/reach model was used to explore multiple irrigation water use scenarios. Because of current federal reservoir operating rules in the Chattahoochee River, irrigation decreases in the Flint River do not always directly translate to elevated flows downstream in the Apalachicola River. In drought years, a large percentage of the Flint River water savings is captured as greater storage volume at upstream Chattahoochee reservoirs because of a requirement to supplement downstream flows to a prescribed minimum level. In nondrought years, the majority of irrigation decreases translate to increased flow in the Apalachicola River. Given these simulation results, public policy decisions need to be formulated with regard to what portion of the Flint River water savings from changing irrigation practices in drought years should be allocated to the upstream Chattahoochee storage reservoirs and what portion to supporting downstream environmental and social needs in the Apalachicola watershed.     

Advances in eutrophication science within Lake of the Woods,a complex transboundary lake – Forward to the special section

Outside of the five Great Lakes, Lake of the Woods (LoW) is the largest transboundary lake shared by Canada and the United States. Over the last two decades, an international consortium of researchers has advanced our understanding of eutrophication science in this complex watershed. This introductory paper outlines eleven research articles included in this special section, within three main themes pertinent to LoW: external phosphorus sources to LoW and internal phosphorus loading, lake and watershed modeling, and new insights into cyanobacterial and harmful algal blooms (cHABs). We conclude with a roadmap to guide future transboundary water quality management in LoW, including remaining research gaps and future monitoring needs.     

基于GWLF模型的新安江上游练江流域面源污染特征解析

应用通用流域污染负荷模型(GWLF),对新安江上游练江流域2005-2012年的水文化学过程进行了模拟,在月尺度上评估了流域把口断面的水量及溶解性总氮污染物通量,并解析了其负荷来源分配。结果表明:GWLF模型能够作为有效的决策支持工具对目标流域开展有效评估,模拟结果纳氏效率系数在0.75以上。从年均水平上看,流域溶解态总氮主要通过地表径流和地下水传输,分别占到全部负荷量的42%和40%,且与流域水文关系密切。水质较差的风险敏感期主要出现在水量较少的时段,且该期间内农村生活源(37%)和点源(9%)贡献相对显著,应予以特别关注。上述流域面源污染特征解析结果能够为实施有针对性的管理措施提供参考。     

Modelling streamflow and phosphorus fluxes in the Lake of the Woods watershed

This study provides an evaluation of streamflow and the spatial and temporal variability of phosphorus (P) fluxes for the transboundary Lake of the Woods (LoW) watershed using the Canadian version of the Soil and Water Assessment Tool (CanSWAT). The model calibration and validation generally indicate good performance for the simulated flow, especially for the Rainy River, the main tributary to LoW, while the sediment and nutrient calibration performance was satisfactory. Model results indicated Rainy River is the primary source of total phosphorus (TP), contributing about 88% of the external non-point source (NPS) and point source P loads to LoW, with the majority being NPS. Simulated TP loads varied seasonally with over approximately 60% occurring during the spring period and varied spatially across the LoW watershed. TP yields tended to be lower upstream of Rainy Lake in the Precambrian Shield (a.k.a., Canadian Shield) and higher downstream of Rainy Lake in the Glacial Lake Agassiz lakebed, particularly in the Lower Rainy and Little Fork sub-watersheds. Point sources along the Rainy River constituted the largest anthropogenic TP source. Tributary P loads estimated by the model were also used in a simple lake mass-balance model that suggested 32–46% of TP load to LoW was retained within the lake.     

Modelling the impacts of grassland to cropland conversion on river flow regimes in Skunk Creek watershed,Upper Midwest United States

Conversion of grassland to cultivated cropland has been linked to downstream alteration of flow regimes. This study used the Soil and Water Assessment Tool (SWAT) to construct seven “what if” scenarios for quantifying the impacts of grassland to cropland and vice versa conversion (i.e., replacement of grassland with selected agricultural crops) on river flow regimes in Skunk Creek watershed. The Cropland Data Layer for the year 2011 in conjunction with historical climate data was used to create SWAT models for scenario simulations over 19 years, from 1996 to 2014. The model developed for the historical climate records (baseline) was compared with the scenarios examined using stream flow metrics for a range of flow regimes, including magnitude, duration, frequency, and timing of annual low‐ and high‐flow conditions. The simulation results suggest that grassland conversion to cultivated cropland would generally increase river flows compared with conversion of cultivated cropland to grassland, which may reduce flows in the watershed. Low and moderate flows increased by 2–8% from the baseline scenario with conversion of grass crop and by 1–20% decreases with crop–grass conversion. High flows increased by 3–7% and decreased by 1–18% when grass is converted to crop and crop to grass, respectively. The analysis also suggests that grassland establishment may attenuate the peaks of prolonged small floods and shorter but earlier large floods.     

流域设计枯水流量分析计算方法

流域枯水流量的大小,主要依赖于流域蓄水量的补给;同时随着流域蓄水量的减少,枯水流量也不断衰减。流域枯水流量与河道通航、城乡供水、水电厂与火电厂设计(运行)和生态环境质量等密切相关。流域枯水流量虽不如洪涝和地震等自然灾害与人类的关系那么剧烈,但它可严重制约工农业生产的发展和人类生活质量的提高。本文详细介绍了流域设计枯水流量分析计算涵盖的枯水调查与资料收集、枯水流量资料的审查与处理、具有实测资料时设计枯水流量的计算、资料不足时设计枯水流量的估算、缺乏资料时设计枯水流量的确定以及设计枯水流量成果的分析论证等6部分内容,以供从事河道航运、城乡供水和环境保护等部门工程技术人员参考,以利于经济社会更好地发展。     

Towards a rights-based approach in EU international river basin governance? Lessons from the Scheldt and Ems Basins

ABSTRACT

This article finds that the introduction of a rights-based approach in EU transboundary river basin management to remedy observed systemic difficulties and to better achieve legal water quality standards could be a next step in achieving integrated river basin management. However, its effectiveness largely depends on the willingness of member states to share river basin districts to subordinate their separate socio-economic interests to ecological needs, as well as to grant a clear mandate and partly transfer responsibilities and powers to a competent supranational authority.     

Estimation of Design Flood Hydrograph for an Ungauged Watershed

Based on the physiographical features of the studied watershed of 102.5 km² in northern Ontario and the meteorological data of one nearby climatic station, through the combination of the regionalization of flood and the HEC-1 modeling, this article presents an approach that may be used to determine the desired peak flows for the ungauged watershed. The empirical equations used to determine the desired peak flows were developed by the Cumming Cockburn Ltd. (CCL) who has carried out the studies on flood regionalization by using flow data at 380 gauging stations in Ontario. CCL has proposed four methods to estimate peak flows, namely 1) regression method describing multiple linear relationships between flood flow and related parameters; 2) index flood frequency curve; 3) regional flood frequency curve and 4) isoline map for unit peak flow. The desired peak flows for studied watershed determined by CCL methods were used to calibrate the HEC-1 model for the rainfall-runoff simulation for this watershed which consists of 15 subwatersheds. Through slight adjustment in the CN number used in the HEC-1 model, the calibrated HEC-1 model could be used for rainfall-runoff simulation for this ungauged watershed. This approach could be recommended for hydrological design and watershed management for ungauged watersheds provided the analyses of flood regionalization could be conducted. In addition, comparing to the Bavaria forest region, Germany, some questions have been discussed in this article.     

Modeling and Simulation of Baseflow to Drainage Ditches During Low-flow Periods

Quantification of baseflow to drainage ditches is essential in understanding flow dynamics in a watershed. The mass balance estimation for a stream section may not give an accurate measure of the baseflow during low-flow periods due to the lack of accuracy in flow measurements in the flumes. Modeling may be useful for estimation of baseflow during low-flow periods. In this study, numerical and analytical solutions of the Boussinesq equation were used to simulate baseflow rates during low-flow periods in two watersheds, namely the Big Ditch watershed and the Upper Embarras River watershed in Illinois, USA. Additionally, MODFLOW was also used to simulate baseflow for these periods. At each site, a stream section of 200 m was selected for baseflow simulation and six observation wells were installed at one bank of each stream section for model calibration. A total of seven low-flow periods were considered for baseflow simulation. The mean baseflow rates simulated by the numerical model were higher than that simulated by the other two models. There is no significant difference between the mean baseflow rates simulated by the analytical model and MODFLOW. It was observed that proper estimation and/or measurement of model parameters were necessary for simulation of reliable baseflow rates. Since flow measurements during low-flow periods may include possible errors, the model results might also be acceptable for all practical purpose.     

Characteristics of sediments in a newly constructed reservoir in Japan.

The sediment formation mechanisms of a newly constructed reservoir in Ehime, Japan were evaluated by characterizing the soil particles (SP) and particulate phosphorus (PP) in the runoff and reservoir sediments. The SP and PP loads from the runoffs of the main river in the watershed considerably increased, when the specific discharge rates were over 300 l/s/km2 (high flow conditions). When the specific discharge rates exceeded over 300 l/s/km2, 19% of the watershed generated over 80% of the SP and PP loads. When the specific discharge rates were under 300 l/s/km2 (low flow conditions), the contributions of the previously mentioned 19% area to the SP and PP loads were smaller. Significant amounts of smectite were found in the sediments in the reservoir and in the soil samples obtained at the forest exposed area in this 19% area while it was negligible in citrus orchards and paddy fields that constituted the remaining land surfaces. The forest area exposed by recent landslides was significant for the SP and PP in the reservoir. Judging from the outcomes, land use information alone may not be sufficient to detect critical sources of SP and PP in the runoffs and reservoirs. To identify and confirm crucial areas for the SP and PP in the runoffs, the investigations should be conducted under high flow conditions and the composition of clay minerals in the sediments should be checked against the clay mineral distributions of soils in the watershed.