Channel Evolution Models as Predictors of Sediment Yield

This paper recounts our predictions of channel evolution of the Black Vermillion River (BVR) and sediment yields associated with the evolutionary sequence. Channel design parameters allowed for the prediction of stable channel form and coincident sediment yields. Measured erosion rates and basin‐specific bank erosion curves aided in prediction of the stream channel succession time frame. This understanding is critical in determining how and when to mitigate a myriad of instability consequences. The BVR drains approximately 1,062 km² in the glaciated region of Northeast Kansas. Once tallgrass prairie, the basin has been modified extensively for agricultural production. As such, channelization has shortened the river by nearly 26 km from pre‐European dimensions; shortening combined with the construction of numerous flow‐through structures have produced dramatic impacts on discharge and sediment dynamics. Nine stream reaches were established within three main tributaries of the BVR in 2007. Reaches averaged 490 m in length, were surveyed, and assessed for channel stability, while resurveys were conducted annually through 2010 to monitor change. This work illustrates the association of current stream state, in‐channel sediment contributions, and prediction of future erosion rates based on stream evolution informed by multiple models. Our findings suggest greater and more rapid sedimentation of a federal reservoir than has been predicted using standard sediment prediction methods.     

MULTICRITERION DECISION MAKING FOR FLOOD CONTROL OPERATIONS: THEORY AND APPLICATIONS1

ABSTRACT: Flood control operations are generally complex in nature, as they are often associated with a large quantity of uncertain factors in combination of noncommensurable criteria. It has been found that the use of fuzzy set theory coupled with multicriterion decision making (MCDM) methods is very promising. In this paper, a multicriterion fuzzy recognition model is established for flood control operations. A subjective preference and iterative weights method is proposed for weight assessment. First, an initial solution of criteria weights, which is directly analyzed from the selected alternatives, is obtained by using the proposed fuzzy recognition model. Then, according to their knowledge related to real time flood operations, operators may modify the initial weights if necessary. When the relative membership grades of alternatives belonging to all rankings are fixed, a defuzzification equation is used to calculate the rank feature value vector. Based on the rank feature value vector, one can evaluate the alternative set. Two flood operation cases are provided to illustrate the application of the proposed model. With the incorporation of the operator's knowledge related to flood operations, the proposed model is flexible in giving weights and realizes more practical flood control operations.     

高海拔水电水库温室气体的排放特征——以雅鲁藏布江藏木水库为例

水电水库是大气温室气体的重要来源,在一定程度上影响着区域气候变化.然而目前关于水库温室气体排放的估算仍然存在很大的不确定性,一方面原因是缺失了世界各地山区水库的数据,另一方面原因是未将受水库影响的上下游河道考虑在内.本研究重点关注雅鲁藏布江流域水电水库——藏木水库丰枯水期CO2、CH4和N2O的溶存浓度与扩散通量的时空...     

安康水库分级超蓄的洪水资源化方法及其风险

汛限水位动态控制是水库洪水资源化的一种重要策略,其核心是在合理权衡风险和效益这一对矛盾的基础上确定可行的水库超汛限水位调度方案。为实现相对较大效益的同时降低水库防洪风险,考虑利用流域降雨预报信息,采用预泄能力约束法,以不同的降雨预报量级为依据,提出分级超蓄的洪水资源化方法,并结合安康水库实例,求得其基于 24 h 小雨和无雨预报的分级超蓄上限分别为326 m和 328 m。通过风险分析得知：在不考虑降雨预报信息的情况下,水库超蓄上限不宜超过 327.5 m;而依据 24 h 降雨预报信息的水库超蓄风险小到可以忽略。最后,应用该超蓄方案对实际洪水进行调度,实现了在减少弃水量069亿m3的同时,增加发电收入约361万元人民币.     

我国尾矿库安全现状分析及管理对策研究

该文首先从规模等别情况、安全生产许可证领取情况、设计状况、服务年限情况、筑坝方式、尾矿库安全度状况、应急预案编制情况、评价状况、排洪设施完好情况、下游情况、库区内违章情况等11个当面对全国尾矿库数据进行了统计,综合分析了目前我国尾矿库安全现状。然后,根据尾矿库安全现状,分析了目前我国尾矿库安全管理存在的主要问题。最后,针对存在的问题,提出了我国尾矿库安全管理建议。     

张家口市洋河、桑干河流域水环境健康风险评价

张家口市洋河、桑干河流域近几年来水质持续改善,为逐步恢复流域水质和下游官厅水库饮用水备用水源功能提供了条件.文章利用水环境健康风险评价模型,选取了2006年该流域水质监测数据,对流域内10个监测断面由饮水途径引起的水环境健康风险进行了评价.结果表明,该流域水体对人体健康危害最大的是化学致癌物Cr(VI),在各个监测断面中Cr(VI)的个人年风险均超过ICRP推荐的标准.同时,化学致癌物对人体健康危害的个人年风险超过非致癌物的个人年风险;因此对该流域水体的含化学致癌物Cr(VI)和As废水进行控制和治理是降低水环境健康风险的有效途径.     

三峡库区消落带富营养化及其危害预测和防治

三峡水库蓄水运行后将出现一个落差达30 m的永久消落带。消落带是水域生态系统与岸上陆地生态系统的交替控制地带,该地带具有生物的多样性、人类活动的频繁性和生态的脆弱性,随着人类活动的影响,已成为湖岸带中生态最脆弱的地带。由于工业和生活用水污染以及水体自净能力下降,消落区富营养化相关物质（如氮和磷）污染会进一步加剧。因此,必须针对库区消落带地区的特殊情况,选择适当的模式对消落带进行超前环境整治和保护,实现三峡库区生态系统的恢复和重建。     

土壤水库和森林植被对水资源的调节作用

以湖南省土地、森林利用状况等有关资料为基础,从土壤和森林对降水形成径流的影响,调节水资源的数量和方式,防洪抗旱减灾方面的作用3个层次,详细地剖析了土壤水库和森林植被对水资源的调节作用。结果指出,土壤水库和森林植被能够调节水资源,其潜力非常大。合理利用土壤水库和森林植被可以蓄水保土减蚀,削减洪峰,减少自然灾害。     

地表水泥沙与总磷测定值的相关性分析

为研究总磷与泥沙之间的质量浓度关系,采集了三峡库区7个断面的地表水样品,通过筛分、滤膜过滤等方式,分离了水样中不同粒径的泥沙,得到含不同泥沙质量浓度的水样,并同步分析了水样中泥沙和总磷的质量浓度.结果表明,在丰水期,总磷主要来源于泥沙中吸附的有机磷和无机磷,而溶解态磷较少.泥沙与总磷质量浓度可以用线性关系和对数关系模拟,泥沙是影响地表水中总磷测定结果的主要原因之一.     

MULTI-OBJECTIVE RESERVOIR OPERATION INCLUDING TURBIDITY CONTROL1

ABSTRACT: The operational problems of a reservoir are expressed by three coordinates: space, time stage, and objective. The operational procedure is formulated using dynamic programming as a multi-objective problem. After comparing the scalar and the vector optimization, the scalar optimization technique is applied to turbidity analysis in a reservoir.