水库运行方式改变对水温的影响

水库出入库流量、运行水位及取水口位置变化所引起的水库运行方式的改变,会对库体内部水温分布及下游河道水温产生一定的影响。本文以新疆某水库为例,运用三维水温模型进行模拟计算。结果表明:维持水库低水位运行或在外界气温、来水水温都较高的汛期实现表孔泄水,均能显著提高下泄水温,且对库体内部水温分布影响较小;不同典型年条件下,水库出入库水量存在差异,丰水年时水温结构所受影响最大,下泄水温的不同主要体现在汛期,最大水温温差出现在8月份。     

观音岩水库水温预测及分层取水设计

为满足灌溉对水温的要求,结合观音岩水库的特点,拟定4种不同的取水方式,并采用东北勘测设计研究院经验公式对每种取水方式所取水体的水温随时间分布、水库泄水温度状况及管道水温沿程变化进行了预测。结果表明,采用4层取水方式,可较好满足农田灌溉对水温的要求。     

亭子口水库垂向一维水温模型研究

亭子口水库是年调节型水库,库水有明显的热分层现象。在充分考虑水面热交换、入流、出流、热扩散、热对流等影响因素的基础上,建立亭子口水库垂向一维水温数值模型。利用1970～1978年的丹江口水库水温实测值与模型预测结果对模型进行验证。将建立的模型应用于嘉陵江亭子口水库水温预测,并分别研究了不同来水量过程、不同泄水条件以及考虑建库后库区变化的气象条件对水库水温结构的影响。     

来流变化条件下溪洛渡水库生态调度期水温分层特性研究

为探明来流变化条件下溪洛渡水库生态调度时的水温垂向分布特性,运用水温现场监测和CE-QUAL-W2模型对水温进行数值模拟的研究方法,基于实测地形和水文等数据建立溪洛渡库区的立面二维水温模型,模拟了水库在2021年1月15日—4月30日的水温动态变化过程,重点分析了生态调度期(3—4月)库区的立面二维水温分布规律及不同泄水口高程对下泄水水温的影响。结果表明：溪洛渡水库坝前水温于3月中旬开始出现温差,3月下旬表底最大垂向温差为2.02℃,垂向温度梯度在0.10℃/m以内。4月上旬、下旬水库表底最大垂向温差分别为2.41和2.81℃,垂向温度梯度在0.15℃/m以内。通过比较无叠梁门、1层叠梁门两种泄水运行工况得出,当设置1层叠梁门稳定运行时水库的平均下泄水水温提高了0.13℃。本研究可为溪洛渡水库后续的水温生态调度试验提供科学依据。     

高坝大库分层取水措施比选研究

为了合理选择大型水库分层取水措施并进行下泄水温对生态环境的影响评估,采用MIKE3数学模型方法,模拟某高坝大库分别采用单层进水口、两层进水口、叠梁门多层取水等3种不同电站取水方案的水库水温结构及下泄水温,对比分析不同分层取水措施对下泄水温的调节作用和对下游生态环境的影响。结果表明分层取水措施能有效提高水库泄水温度,减缓水库下泄低温水的影响;叠梁门结构能够实现表层取水,对水库低温水的改善效果要优于多层进水口结构。     

水库水温垂向分层模型及黑河水库水温预测

水库水温垂向分层模型将水库水体离散为具有一定厚度的水平层次，同一层内水体充分混合，水温相同，在此基础上考虑太阳辐射、出入水流、垂向扩散及密度对流等因素，根据质量、热量平衡原理计算各层水温。对黑河水库水温结构的预测表明，水温的垂向分布与径流过程和水库运行方式关系密切。建议水库设置活动分层取水设施，并在泄水方式上适当考虑对温跃层的破坏和对农灌水质的影响。     

山口岩水库水温计算及其对下游河道水温影响分析

对山口岩水库水温分布、水库泄水温度状况及坝下游河道水温沿程变化作了预测,结合灌区工程布置及灌溉农田的基本情况,对水库兴建后水温对下游农田灌溉的影响进行分析评价,结果表明:库区水温结构属典型的分层型;在坝址至半山水汇入口6km长的河段水温回升较慢,年平均水温温升率为0 414℃/km,对应的左岸直灌区和锡陂灌区沿程水温在水稻生育期的月平均值低于水稻生长所需的最低水温,需采取调温措施;在坝址下游10km断面,由于受袁河支流半山水汇入影响,各月平均水温与建库前天然水温相差不超过0 3℃,能满足农田灌溉的要求。最后从工程设计、水库调度运行、灌溉方式等方面提出了对策措施。     

水库泄放冷水对鱼类的影响

水库泄放下层冷水对下游河水温度的影响包括：缩小季节性水温范围(最高水温降低。最低温度升高)、减小白天水温变化、水温快速变化及推迟水温的季节性变暖。当地淡水鱼的生理发育因水库泄放冷水而受影响，其可持续性和寿命受到严重损害。研究表明，将整个春季泄水的温度提高2℃、4℃、6℃和8℃，可增加鱼卵孵化机会和幼鱼的存活率。     

三峡水库香溪河库湾不同异重流下水温分层模式研究

三峡水库蓄水后支流库湾水体的水动力条件发生变化,水温在垂向上的分布也呈现出了不同模式。为了分析不同类型的倒灌异重流条件下水体的水温分布情况,对香溪河库湾不同断面的水温进行原位监测,并构建库湾水体的水温水动力数学模型(CE-QUAL-W2)。研究结果表明:水库正常运行的不同时期,香溪河库湾水体的主要水动力条件和水温分布结构均不同,在水库运行时的泄水期,库湾水体水动力主要为表层倒灌异重流,水温呈现传统的分布模式;在水库汛期低水位运行时,库湾水体水动力主要为中层倒灌异重流,水温呈“双混斜”式分布;在水库蓄水期,库湾水体水动力主要为底部倒灌异重流,水温呈“半U”型分布。研究成果可为揭示香溪河水流水温特性、营养盐迁移及水华预测预报提供相关的理论支持和技术支撑。     

基于和谐理念水库调度方式的研究

现行水库调度方式对河流健康的环境影响主要有:改变河道形态、拦水拦沙影响上游与河口环境、阻隔河流系统的空间联系、影响流域陆地水文条件、库岸滑塌、影响地下水和流域的水质、改变流态影响水温和加剧污染等。对河流健康的生态影响主要有:减少流域生态物种、威胁河口湿地上的生态物种、阻隔鱼类洄游路线、影响水生物的生命周期等。提出了和谐理念水库调度措施:实施水位优化调度、分层分段泄水保障水质、结合防洪适时适量泄水改善库内水质、分层放水以消除水库下游水温异常、人造小洪峰以满足下游生物繁衍需求等。     

TRACING GROUNDWATER DISCHARGE IN THE FLOODPLAIN OF THE PARANA RIVER,ARGENTINA: IMPLICATIONS FOR ITS BIOLOGICAL COMMUNITIES

Groundwater discharge can be an important determinant of the functioning of aquatic environments and their associated biological communities. However, the presence and the importance of groundwater have not been considered in the Parana River floodplain owing to the large quantity of surface water. The present study aimed to identify groundwater discharge conditions in a sector of the middle of the floodplain of the Parana River by studying groundwater flow systems. Eight piezometers were installed to record groundwater movement in the vertical plane weekly for 2 years. Water samples were collected in piezometers, domestic wells, the river and other water bodies to study the groundwater flow systems. Rising of the water level during piezometer installation and recording suggested that the study zone represents groundwater discharge conditions. Residence time proxy allowed identification of local flows and intermediate flows. Local rainfall (in Santa Fe) showed an isotopic signature (δD and δ¹⁸O) similar to some local flows detected in the study zone, and this suggested local recharge. The chemical characteristics of an intermediate flow suggest that water would have travelled from a recharge area ~30 km from the study zone. Local rainfall and the intermediate flow have different isotopic signature. Results suggest that the willow forest is associated with the recharge area of a local flow, which plurispecific‐canopy forest is related to a transit area of a semi‐intermediate flow, and that tall grassland and marshy community colonize discharge areas of local and intermediate flows, respectively. Copyright © 2012 John Wiley & Sons, Ltd.     

表孔分流坎挑流消能工在龙潭拱坝中的应用

龙潭高以曲拱坝表孔挑流泄洪，水头高，泄量大，河谷窄，溢流堰布置受坝体厚度限制，采用新型分流坎挑流消能工，使水流在空中扩散，碰撞，消能效果极佳，大大减轻了泄流对河床的冲刷破坏作用，在国内已建高薄拱坝泄洪中为首次建成运行。     

FLOW FIELD CHARACTERISTICS OF THE SAND FUNNEL AND ITS MECHANICS OF SEDIMENT TRANSPORT

The flow in funnel chamber is typical three-di-mensional flow. The experimental results of clear water flowfield and muddy water flow field show that the flow character-istics in the funnel chamber are favorable to the separation ofwater and sand. Tangential velocity sustains the vortexstrength of the funnel chamber, axial velocity is benefit to thesediment sinking, and radial velocity is benefit to sedimentmoving to desilting hole. So the sand funnel is successful insediment disposal. The sand funnel projection has also gooddesilting effectiveness in practice. Its average flushing dis-charge is 3% of inlet canal discharge, the sand disposal rate is100% for the sand with grain diameter of more than 0. 5mm,and is more than 90% for the sand with grain diameter of lessthan 0. 5mm.     

SIMULATIONS OF THE THREE-DIMENSIONAL TOTAL DISSOLVED GAS SATURATION DOWNSTREAM OF SPILLWAYS UNDER UNSTEADY CONDITIONS

Dams are often operated in a way to discharge over the spillways, which would cause a high dissolved concentration of air and be harmful to fish. The bubble transfer and the water surface transfer play an important role in affecting the concentration of the Total Dissolved Gas (TDG). Based on recent numerical simulations of the total dissolved gas saturation, in this article, a two-phase TDG transport equation is adopted to develop an unsteady three-dimensional (3-D) two-phase flow Computational Fluid Dynamics (CFD) model, including a number of parameters such as water depth, pressure and air volume entrained. This model is used to predict the hydrodynamics and the TDG distribution under unsteady discharge conditions. Good agreement between measured and numerical results is obtained for a case study.     

TIMING OF REDD CONSTRUCTION BY FALL CHINOOK SALMON IN THE HANFORD REACH OF THE COLUMBIA RIVER

Spawning habits of fall Chinook salmon in the Hanford Reach of the Columbia River have been documented with annual aerial surveys since 1948. We developed a series of models analysing these data, exploring the influence of environmental factors on the timing of redd construction. These models included a logistic regression and a dynamic modelling approach, with combinations of day of year (as a surrogate for environmental cues such as day length), water temperature and discharge as potential explanatory factors. Results of these analyses indicate that day of year was the strongest predictor of the timing of redd construction, but with significant modifying effects of water temperature and discharge. The dynamic modelling approach provides substantial advantages over a traditional logistic regression, including (1) the ability to treat data collected at non‐synchronous time intervals in a consistent fashion and (2) the ability to easily implement complex functions (e.g., threshold responses) relating behaviour to environmental cues. Evaluation of the series as a whole indicates that the median date of redd construction has increased over time, from approximately day 299 in 1950 to day 307 in 2010, as has the temperature on Oct 1 (16.3 °C–18.1 °C). The degree to which these changes are caused by climate change or dam operations is uncertain, however. Copyright © 2013 John Wiley & Sons, Ltd.     

信江尾闾防洪对策选择

分析了梅港站多年洪水流量水位关系，得出信江尾闾相同洪水流量下水位逐年抬高的结果，通过方案比较选择了信江尾闾整治实施方案。     

水库库首水温分层流物理模型试验分析

大型水库由于水温分层现象易对生态环境造成一系列不利影响,但由于水深较大现场测量困难,水温分层的实测资料极少,对其研究尚不够深入。通过物理模型试验模拟并测量了春末夏初水库库首水温分层的形成和演化过程,分析了流量和出水口位置对水温在垂向和水平分布的影响。结果表明:① 由于分层流流动的特点和水动力条件的差异,水温垂向结构在温度分层的演化过程中表现为多种形式。② 垂向温差取决于上下游位置、入库流量和水库出水口的高度。通常在垂直方向上,上游温差要比下游大。随着进水口流量的增加和出口位置高度的提高,垂向温差也随之加大。③ 水平方向上的水温分布与水深、进水口流量和出水口高度有着密切联系。在水库的表面和中部位置,上游水温要高于下游水温。然而在特定条件下,如进水口流量较大且出口位置在表面时,上游水温要低于下游水温。④ 水流的出口温度受进水口流量和出水口位置的影响。较低的出水口位置会导致出水温度较低,在初始时段尤为明显。     

潭口水文站流量测验单值化巡测分析

根据<水文巡测规范>(SL195-97)和<水文资料整编规范>(SL247-1999),对潭口水文站1990～1999年的水位流量关系资料进行了统计分析,采用历年综合线推流,达到了完整、准确收集水文资料目的.     

水利水电工程对鱼类的影响及保护措施

主要介绍水利水电工程建设对鱼类产卵、鱼类栖息地、鱼类洄游、鱼类区系等的影响,及水利水电工程导致的下泄水温、气体过饱和对鱼类的影响,同时介绍过鱼设施、人工增殖放流等保护措施;阐述水电工程对鱼类产卵的影响,提出根据不同鱼类的洄游时间、产卵和孵化条件要求,因时因地选取不同的引水方式组合,如底层取水、表层取水、中下层组合取水、...     

EXPERIMENTAL INVESTIGATION ON THE FLOW THROUGH HANGED-PLATE OF THE TWO-STOREY INTAKE

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