里运河底泥CODCr和NH3-N释放对水质的影响实验

通过利用长江水体作为上覆水的里运河表层底泥的释放实验研究，分析了表层底泥中CODCr和NH3—N在静置和3种扰动条件下的释放规律，结果发现城区段底泥中CODCr和NH3—N的释放强度大于非常区段，底泥孔隙水与上覆水之间的浓度梯度增大促进了底泥中污染物质的更快更多地释放。同时得出了各个断面表层底泥中CODCr，和NH3-N的释放强度，在扰动条件下的释放强度远大于静置条件下的释放强度，底泥中污染物质的释放可能会在一定程度上影响里运河将来的调水水质。     

北江流域径流量分布规律及其变异性分析

以北江流域主要控制性水文站石角站近45年（1956～2000年）径流量序列为基础，分析了北江流域径流变化的基本特征，结果表明径流年内分配不均，年际变化大，年径流量系列呈缓慢上升趋势，并存在2年左右的变化周期，1992年前后发生了一次跃变，但跃变的成因与趋势的成因不一致，趋势与人类活动有关，而跳跃主要受降雨的影响。     

珠江洲头咀河段过江隧道工程极限冲刷模拟研究

珠江三角洲河网纵横交错,网河河道的泥沙来源既有上游不同径流挟带的陆域来沙,也有潮流所挟带的海域泥沙,河道水动力和冲淤特性极为复杂。以广州出海水道上段(广州-黄埔段)为例,在分析河道不同径潮组合下河道水动力特点的基础上,采用二维潮流泥沙数学模型对工程所在河道的极限冲刷进行了模拟计算。研究表明,对于三角洲复杂网河河道,认识不同的径流条件下河道的水动力特点是研究河道冲淤特性的前提。     

三峡地区脆弱生态环境问题初探

脆弱生态环境是一种对环境因素改变的反应敏感而维持自身稳定的可塑性小的生态环境系统，三峡地区脆弱生态环境的基本特征为：侵蚀作用强烈；抗干扰能力弱；土地退化，土地生产力衰减；森林生态系统衰退，环境灾害加剧，灾种增多，频次增高，形成三峡地区脆弱生态环境的因素包括地质地貌因素，气候因素以及人为因素和社会经济因素，三峡地区生态环境的整治措施主要包括：控制人口增长；调整产业结构；开展综合治理；唤起环境意识，依     

Integrated modeling and assessment of water resources and water environment in the Yellow River Basin

An integrated model is established to simulate both hydrological processes and accompanied pollutant transfer processes in the Yellow River Basin. The model couples distributed hydrological model WEP-L (Water and Energy transfer Processes in Large river basins) and a newly developed water quality module which includes simulation functions of soil erosion and sediment transport, and non-point and point sources transfer to rivers. To overcome the defects of traditional water quality assessment, two aspects of improvement are conducted. One is the improvement of the traditional characteristic channel length approach, i.e., the product of multiplying channel length by lateral section area is selected as a new assessment criterion to reflect the different contributions of small channels and big ones, thus making the assessment results more objective. The other is the suggestion of integrated assessment approach for both water at channel lateral sections and water generated in sub-basins. The assessment results in the Yellow River Basin illustrate: (1) the improved characteristic channel length approach shows rivers of water quality worse than Class III account for 75% whilst the traditional approach give a result of 45%, implying that the actual status of water quality is worse than the traditional understanding; (2) the quality of water generated in sub-basins is much better than the quality of water at channel lateral sections. The assessment results describe the status of water resources quantity and quality from different points of view and thus provide valuable information for the water resources development and management in the basin.     

大通河调水对水资源及生态环境的影响

基于生态需水、河流纳污能力、水环境容量等理论,分析研究大通河调水前后可能引起的河道生态环境各要素变化的程度和范围。结果表明,跨流域调水将引起不同河段水资源的剧烈变化,特别是天堂寺、享堂河段会产生断流,进而对河道内生态、水环境及河谷周边陆地生态产生显著影响。综合各方面需水要求,下泄月平均流量至少不小于1.1 m3/s。     

乌江流域大型复杂水电站群联合优化调控关键技术及其应用研究

根据乌江流域总体规划、长江三峡以上防洪要求、南方电网运行特点、乌江流域水文特性等,贵州乌江水电开发有限责任公司组织开展了乌江梯级水库优化调度和发电优化控制的基本理论研究,并根据该研究建立了乌江流域水电站群联合优化调控系统,经过一系列优化调度规则、方法、措施在系统中的应用,实现了节水增发电的目的,取得了良好的社会经济效益。     

广西河道管理和保护范围确权划界探讨

分析了广西河道管理范围和保护范围确权划界工作存在的问题,总结了广西近年来河道管理范围和保护范围确权划界的做法和经验,提出了下一步促进河道管理范围和保护范围确权划界工作的思路.     

Salmonid observations at a Klamath River thermal refuge under various hydrological and meteorological conditions

The Beaver Creek confluence with the main‐stem Klamath River was studied to assess salmonid use in a thermal mixing zone under various summer hydrological and meteorological conditions. Main‐stem flow releases from Iron Gate Dam ranged from 17 cms (615 cfs) to 37 cms (1320 cfs) during the study period and main‐stem water temperatures ranged from 19.5 to 26°C. A grid was constructed to define the thermal refuge as a system of cells. Temperatures were monitored using remote temperature loggers and fish counts were conducted using daytime snorkelling. Most juvenile salmonids were observed moving into the refuge when main‐stem temperatures exceeded 22–23°C. Salmonids in the thermal refuge did not necessarily seek the coolest water, but were generally located in habitats commensurate with species‐specific behavioural needs within their thermal tolerance range. Such ranges largely occurred within refuge areas. Variable meteorological conditions confounded observable biological thermal benefit to fish resulting from higher or lower main‐stem flows. Thermal regime dynamics indicated that under the hydrological and meteorological conditions observed, higher flows from Iron Gate Dam showed some ability to change the structure of the refuge area. It appeared that without the thermal refuge, main‐stem flows alone could not sustain the salmonid population because high water temperatures usually exceeded their published thermal tolerance limits. Copyright © 2007 John Wiley & Sons, Ltd.