A LAW AND ECONOMICS APPROACH TO RESOLVING RESERVOIR SEDIMENT MANAGEMENT CONFLICTS1

The loss of the world's reservoir capacity to sedimentation can be mitigated by altering dam operations to release sediment downstream. However, legal uncertainty regarding whether dam owners are liable for damages to surrounding landowners due to altered operations provides a significant disincentive for sustainable sediment management. Past work recommends that courts apply a “rule of reasonableness” in assessing liability: dam owners should be held liable for damages only if they act unreasonably in altering operations, and surrounding landowners should take reasonable measures to mitigate foreseeable damage. Based on past cases, judicial determinations of reasonable reservoir management and reasonable precautionary measures by landowners are generally highly speculative, controversial, and based on limited information. Courts can ease the future burden of making these difficult determinations with rulings that create economic incentives for parties to act reasonably. For example, courts might entitle landowners to be free from sediment related damages, and protect the entitlement with a liability rule. This gives dam owners an economic incentive to release sediment only if the benefits of doing so outweigh court ordered damages to landowners. Past judicial decisions are largely consistent with this legal regime.     

THE RELATIVE INFLUENCE OF DAMS AND SECULAR CLIMATIC CHANGE ON DOWNSTREAM FLOODING,AUSTRALIA1

An examination of 100 years of flood record at Windsor on the Hawkesbury River in Eastern Australia suggests that Warragamba Dam, which encloses 62 percent of the catchment area, has negligible effect upon flooding. Secular climate change is the important variable in determining changes in flood regime.     

Evaluation of a System to Automatically Sample Zooplankton From the Discharge of Dams1

ABSTRACT: Automatic plankton samplers installed at two dams on the Connecticut River Continuously monitored crustacean zooplankton from October 1977 through 1979 and allowed a significant reduction in man-hours involved in an extensive sampling program. Automatic samplers efficiently sampled most species and size classes of crustacean zooplankton in a similar, but not consistently identical manner as a commonly used towed-net plankton sampler. The smallest sized zooplankton were captured more efficiently than the largest. Mesh selection and sampler avoidance exerted different influences on automatic samplers and towed nets. Future use of the samplers and direct comparison of results to results obtained by other methods was supported.     

DAM‐INDUCED MODIFICATIONS TO UPPER ALLEGHENY RIVER STREAMFLOW PATTERNS AND THEIR BIODIVERSITY IMPLICATIONS1

ABSTRACT: This study evaluates the streamflow characteristics of the upper Allegheny River during the periods preceding (1936 to 1965) and following (1966 to 1997) completion of the Kinzua Dam in northwestern Pennsylvania. Inter‐period trends in seasonal patterns of discharge and peak flow at three downstream sites are compared to those at two upstream sites to determine the influence of this large dam on surface water hydrology. Climatic records indicate that significant changes in annual total and seasonal precipitation occurred over the twentieth century. Increased runoff during the late summer through early winter led to increased discharge both upstream and downstream during these months, while slightly less early‐year rainfall produced minor reductions in spring flood peaks since 1966. The Kinzua Dam significantly enhanced these trends downstream, creating large reductions in peak flow, while greatly augmenting low flow during the growing season. This reduction in streamflow variability, coupled with other dam‐induced changes, has important biodiversity implications. The downstream riparian zone contains numerous threatened/endangered species, many of which are sensitive to the type of habitat modifications produced by the dam. Flood dynamics under the current post‐dam conditions are likely to compound the difficulties of maintaining their long‐term viability.     

The International Environmental Expert Panel for Major Dam/Reservoir Projects: The Yellow River, China

The experience of the International Expert Panel on Environment for the Xiaolangdi dam/reservoir project in China (XEP) showed that the Panel meetings resulted in a marked improvement in project environmental performance by all parties participating in project implementation, with no parties exempt from the Panel's evaluations. Unfortunately the Loan Agreement authorizes use of the Panel only through the project stages of final design and construction, hence the 12th Panel meeting, which matched project construction completion, ended this series. The Panel has recommended that some meetings of the Panel be held during the project's operations stage in order to maintain continuing attention to environmental needs. The XEP experience showed that the XEP, in addition to monitoring project environmental performance, was very valuable for (i) training of Chinese staff involved in project implementation, and (ii) serving in the role as expert consultant for guiding the work of the Chinese participants. The XEP experience also showed the need for making a clear separation between evaluation, the overall resettlement program per se, and the environmental effects of the program. The Panel recommended that the Ministry of Water Resources and World Bank cooperate in sponsoring a book on The Environmental History of the Xiaolangdi Project, including both dam construction as well as resettlement problems, which would serve as a very valuable reference for guiding environmental planning for future dam projects in China (Ludwig, H.F. 1994–2000).     

小型尾矿库存在的问题及溃坝事故树分析

在对20家小型尾矿库现场检查和安全评价的基础上,分析了尾矿库安全管理和安全评价工作中存在的问题,应用事故树分析法对尾矿库溃坝事故进行了具体分析.     

拦河闸工程设计和施工中的风险分析和管理

水利工程的风险分析和风险管理正日益受到工程界的重视。渭河宝鸡市区段拦河闸工程的规划、设计和施工过程中的各项关键决策，都应用了风险分析与管理的方法，包括闸址及蓄水区地质条件的风险分析与管理、泄洪能力及运行风险分析与管理、工程施工过程风险分析与管理、拦河闸工程环境影响风险分析与管理以及拦河闸工程投资风险分析与管理。工程的按时完工、运行的可靠性和安全性，在很大程度上都得益于项目的风险分析与管理工作的贯彻和实施。实践证明，在水利工程决策过程中引进风险分析和风险管理是必要和有益的。     

浙江文成地震水坝现场调查

2006年2月4日起，浙江省温州市文成县连续发生了多起有感地震，其中最大的震级为Mt4．6。地震发生后，中国地震局派遣的工作组对文成县的水库大坝进行了现场调查。这里介绍了地震的概况和现场调查的情况，以及基于地震监测和日常监测（坝体变形、坝体表面检查等）的结果，对坝体的安全性进行了评估，并提出了一些建议。     

基于能值分析的大坝生态效应评价——以尼尔基大坝为例

能值分析可提供客观真实的统一量化平台,在自然、经济系统整合分析方面具有显著优越性.将能值分析方法引入大坝生态效应评价,提出基于能值分析的大坝生态效应评价概念框架,绘制库区生态系统能值流图,构建包括生态系统运行效率、生态系统组织结构、生态系统功能维持和生态系统环境安全4方面共9个指标的能值综合评价指标体系.对尼尔基大坝建设前后库区生态系统变化进行对比性评价,结果表明,生态系统的运行效率、功能维持能力有较大提升,组织结构出现不平衡,环境负荷较高,可持续发展能力受损,需减少因流域水土流失与塌岸导致的库区泥沙淤积,以控制不可更新资源能值输入.     

双台子河橡胶坝对支流绕阳河纳潮的影响

基于Mike11 HD和AD模块建立双台子河口区感潮河段水动力-水质耦合模型,利用实测资料对水动力、水质模型参数进行了率定和验证。利用所建模型,以夏灌期为例分析了在两种水文条件下橡胶坝对支流绕阳河纳潮的影响。结果表明,在两种水文情景下,建橡胶坝后纳潮量分别增加18.3%和16.9%,最大流量分别增加了32.7%和31.2%。盐度分析表明修建橡胶坝对绕阳河纳潮盐度变化影响不大,可满足苇田灌溉对盐度的要求。研究结果可为盘锦双台子河口苇田科学灌溉、促进增产提供技术支持。