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1.
自强水库位于陕南秦巴山地中低山地貌区,水库为镇巴县备用水源地及旅游观光风景区,属小(1型水库。通过对库坝区地质构造、地层岩性、岩溶发育等工程地质条件分析可知,对工程建设及坝线选址有影响的工程地质问题主要为库区内发育逆冲叠瓦小断裂以及岩溶发育可能导致水库渗漏等。库区内无大型活动性断裂构造,构造较为稳定,且库区蓄水范围小,蓄水量不大,不易诱发地震。而拟选坝址位于自强河段,沟谷对称顺直,综合水库坝址区地形地貌、工程地质等条件进行坝线比选,推荐下游坝线为较为理想的坝线位置,可满足工程建设要求。 相似文献
2.
A preliminary assessment of the Wujiangdu Reservoir examined nutrient distribution and transport. Water samples were collected in the summer (July) of 2004, during the high-flow season. Inorganic nutrients (N, P, Si) and chlorophyll a (chl a) concentrations of the Wujiangdu Reservoir and its inflow rivers were analyzed. Other water parameters (dissolved oxygen, pH, temperature, and electrical conductivity) were measured as well. The results show gradually decreasing concentrations of NO3 ?-N and dissolved silicate in the surface water moving downstream to the dam of the Wujiangdu Reservoir. Additionally, soluble reactive phosphorus concentrations measured very low, with most falling below the sensitivity threshold of the method used in surface waters. Particulate phosphorus and NO3 ?-N were the predominant species of phosphorus and nitrogen in the reservoir, respectively. The concentration of nutrients in the Yeji River was the largest of all inflow rivers. The maximum concentration of chl a was found near the dam. These results reflect upstream conditions similar to that of a river, and reservoir conditions near the dam similar to that of a natural lake system. 相似文献
3.
Gyoo-Bum Kim 《Environmental Earth Sciences》2013,69(6):2059-2072
Though the geologic barrier surrounding a dam reservoir plays an important role in preventing water seepage to the outside of a reservoir, a detailed survey to assess bedrock conditions of the whole reservoir boundary is seldom performed when designing a dam. In this study, a variety of investigations and analyses have been conducted to reveal a seepage phenomenon through a reservoir boundary composed of highly fractured metamorphic rocks at the Daechung multipurpose dam. At the study site, groundwater levels at monitoring wells located close to a reservoir tend to change proportionally to reservoir water levels, usually with a rapid response time of 1 day or less. Soil moisture content also changes with respect to the reservoir water level, and the area where seepage from the reservoir is a possibility has a relatively high soil moisture content. The similarity of measured seepage rates at the outflow site and the seepage rate estimated by Darcy’s law suggests strong connectivity and high density of the fractures. The estimated seepage rate using a numerical model for the northernmost valley (Zone 1) is approximately 127.2 m3/day in the case of high reservoir water level and 24.3 m3/day in the case of low water level. Continuous monitoring to obtain time series data for water levels, quality, and bedrock displacement is recommended to assess the sustainable stability of this geologic barrier. 相似文献
4.
针对澜沧江高坝大库对物质迁移转化的影响问题, 自主研发了深库智慧采样设备和潜流带动态监测系统, 于2016年、2017年、2018年开展了澜沧江上游1 290 km的9个梯级水库的监测分析, 实现了280 m最大工作水深的垂向分层水样与沉积物样无扰动采集和潜流带水土环境界面的多指标监测。研究发现: 梯级水库促进了水体中生物有效磷、氨氮占比和沉积物中生物有效磷释放的沿程增加;沉积物中甲基汞的分布与泥沙颗粒沉降有关, 受到水力停留时间和库龄的共同调控;温室气体的排放通量因建坝有所提升, 但远低于世界平均水平;潜流带因干湿交替频率和面积的增加, 加强了水库关键带脱氮和温室气体削减效应;水库中微生物群落并未因建坝隔离, 在沿程和垂向上, 水温都是其关键影响因子。 相似文献
5.
This study concerns Tarbela dam reservoir which is a major resource of Pakistan in terms of electricity generation and irrigation
supplies. Rapid filling of reservoir due to sediment transported and deposited by Indus River is described and analysed in
this article. Causes of sediment deposition and their impact on dam’s function and life are studied. The main characteristic
parameters of the site are presented. The morphological evolution of the reservoir bed induced by dam construction, between
the year 1974 when the River bed was in its original state before dam construction, and the situation of the river bed after
the deposition of the sediment in the year 2006, is examined. A numerical model developed in this study (Khawaja and Sanchez
in Tarbela dam: a numerical model for sediment management in the reservoir; coastal and maritime mediterranean conference,
1st edn, Hammamet, pp 111–114, 2009) allows obtaining the above-stated provisional evolution of the reservoir over the coming years. Finally, five potential
remedial solutions are thoroughly discussed. 相似文献
6.
An investigation and remediation of instability along upstream cut slopes for an earthfill dam in differentially weathered rock in southern Turkey is described. The major instability problem was a 45-m high and 200-m long previously cut slope next to the main axis of the dam, above the diversion tunnels and water outlet structures. The slope was first designed and excavated in 1986 based on the temporary berm approach. Rising water level in the reservoir would change the shear strength parameters and the pore-water pressure in the slope; thus, probable deep failure would damage the entrance of the diversion tunnels and water outlet structures, as well as the earthfill embankment of the dam. In June 1996, the slope face was re-excavated and protected against wave erosion by placement of a layer of rock riprap over a layer of bedding and a filter material. A strong earthquake (MS = 6.2) occurred during a period of rapid drawdown in 27 June 1998. The slope remained stable, although numerous tension cracks developed in Quaternary terrace deposits near the reservoir area. 相似文献
7.
北盘江流域沿线山高谷深,岩溶水文地质条件复杂,局部区域水资源短缺,岩溶渗漏问题成为水利水电工程建设的瓶颈。文章综合地质调查测绘、钻探及物探、水文地质试验、岩溶水系统分析、地下水均衡分析等方法,论证了PCH水库不会发生邻谷渗漏及绕坝基深部的岩溶管道型渗漏,但发生溶隙型渗漏的可能性较大。采用有限元法模拟溶隙渗漏显示:随着T1yn1-1灰岩溶蚀率的增大,坝基抗滑稳定系数稍有降低,潜在失稳模式为后缘剪断T1yn1-2岩体,前缘沿T1yn1-2层内岩屑夹泥型软弱结构面剪出;坝基渗漏量呈线性增加,T1yn1-1灰岩溶隙密集带为坝基主要渗漏区。当溶隙密集带沿T1yn1-1灰岩与T1yn1-2泥灰岩接触带水平发育且集中分布时,坝基抗滑稳定系数将明显减小,坝基渗漏量将明显增大;当溶隙密集带垂直发育、分散发育或主要分布于坝后区域时,其对坝基抗滑稳定及坝基渗漏量影响微弱。岩溶水文地质分析及数值模拟均显示,复杂岩溶水系统势汇区下游区域多以溶隙渗漏为主,其工程影响有限,具备建坝成库条件。 相似文献
8.
Baozhusi reservoir is a large-scale hydropower engineering project in Sichuan Province, China. After drainage wells were drilled in the dam base, white flocculent and black gel substances, accompanied by a rotten-egg odor, were found in some of the drainage water wells. On the basis of a brief introduction of the geological setting in Baozhusi Dam area, the origin of the abnormal substances were analyzed and discussed through the following procedures: (1) the abnormal substances were sampled and their chemical and mineral compositions were analyzed; (2) the origin of drainage waters were determined using the isotope method and well flux measurement results; (3) characteristics of chemical composition of drainage waters were discussed relative to other kinds of waters in the area; (4) process of formation of the abnormal substances were determined using hydrogeochemical methods; (5) laboratory immersion experiment was carried out to verify the conclusions. Results showed that the abnormal substances were formed by interactions between recharging water from the reservoir and dam base rock as well as dam building materials. Among these, the precipitation of calcite and dolomite, the dissolution of calcium hydroxide and anhydrite as well as the reduction of SO4–2 to H2S by organic matter are the most important processes. 相似文献
9.
Kenneth S. Johnson 《Environmental Geology》2008,53(5):945-950
Gypsum is a highly soluble rock and is dissolved readily to form caves, sinkholes, disappearing streams, and other karst features
that typically are also present in limestones and dolomites. Gypsum karst is widespread in the USA and has caused problems
at several sites where dams were built, or where dam construction was considered. Gypsum karst is present (at least locally)
in most areas where gypsum crops out, or is less than 30–60 m below the land surface. These karst features can compromise
on the ability of a dam to hold water in a reservoir, and can even cause collapse of a dam. Gypsum karst in the abutments
or foundation of a dam can allow water to pass through, around, or under a dam, and solution channels can enlarge quickly,
once water starts flowing through such a karst system. The common procedure for controlling gypsum karst beneath the dam is
a deep cut-off trench, backfilled with impermeable material, or a close-spaced grout curtain that hopefully will fill all
cavities. In Oklahoma, the proposed Upper Mangum Dam was abandoned before construction, because of extensive gypsum karst
in the abutments and impoundment area. Catastrophic failure of the Quail Creek Dike in southwest Utah in 1989 was due to flow
of water through an undetected karstified gypsum unit beneath the earth-fill embankment. The dike was rebuilt, at a cost of
US $12 million, with construction of a cut-off trench 600 m long and 25 m deep. Other dams in the USA with severe gypsum-karst
leakage problems in recent years are Horsetooth and Carter Lake Dams, in Colorado, and Anchor Dam, in Wyoming. 相似文献
10.
通过分析大连地区水资源特点及人工控制现状,得出区内水资源仍具有人工调控潜力的认识.结合流域径流资源、区域人工控制特点分析,及有坝地下水库技术研究,筛选设计出5项地表水利工程、7项地下水库工程及13处地下水库潜力区.水量分析表明,通过加大水资源的人工调控,可净增水资源利用量4.38亿m3/a,完全可以解决近期供水问题,增强了大连地区应急水源的保障能力. 相似文献
11.
It is assumed that the groundwater dam under consideration is located in the lower Oshipcheon River along Yeongdeok-gun County, Gyeongsangbuk-do Province, eastern Korea. In this study, changes in groundwater level and construction effects of the groundwater dam were analyzed using a SWAT–MODFLOW model designed for integration of surface water and groundwater, and validity analysis before and after construction of the groundwater dam was evaluated. There are an average increase of 0.46 m and a maximum increase of 1.16 m, respectively, at the upstream region due to the groundwater dam. Groundwater levels at the upstream region show an average increase of 0.42 m by the groundwater dam when the water quantity of demand (10,080 m3/day) is pumped. The groundwater dam has potential as an alternative for the surface water dam to secure water resources in the study area. 相似文献
12.
关于地下水库几个问题的探讨 总被引：38，自引：3，他引：38
赵天石 《水文地质工程地质》2002,29(5):65-67
本文重点探讨了地下水库的基本概念，分类和它的组成，包括由天然储水构造组成的地下水库库区，拦截地下径流的地下坝，地表拦水工程和引渗工程，地下水开发工程4个基本部分和其它组成部分，还探讨了地下水库的优势和问题。 相似文献
13.
Gholamreza Asadollahfardi Mohamad Fatemi Aghda Mehdi Rahbar 《Journal of the Geological Society of India》2013,82(5):553-560
Latian dam is located in the North East of Tehran in Elburz Mountain. It falls in the category of large dams according to the International Committee on Large Dams (ICOLD). It was constructed in 1967 for agricultural purposes, drinking water, and power generation. Producing triggered earthquakes may be a consequent result of dam construction. In this paper, the complete seismic statistics of the region from 1996 onwards has been studied to understand the seismic condition of Latain region. For this purpose, frequency of earthquakes within a radius of 30/60 km around the dam is studied considering its relationship with the reservoir volume variation. Using Gutenberg-Richter rule, parameter b of the region was determined within the same region. The results of this study show the existence of triggered seismicity around the reservoir of Latian dam. Considering the tectonic-geological condition of the region, the existence of triggered earthquakes may create landslides in the reservoir and around it. 相似文献
14.
S. García-López J. Benavente J. J. Cruz-Sanjulián M. Olías 《Hydrogeology Journal》2009,17(7):1779-1790
Regulatory actions taken in the Adra River basin (746 km2), located south of the Sierra Nevada Mountains (SE Spain), are analyzed. The Benínar Reservoir (60 hm3), which entered into service in 1983, has suffered from severe leakage from the outset, preventing it from performing the water management functions originally foreseen for it; however, it has also made it possible to determine the response of the underlying carbonate aquifer into which the reservoir water is draining. This response has been studied based on historical data as well as the occurrence of an extraordinary recharge produced by a period of exceptionally heavy rainfall. A conceptual model of the system’s functioning has been established by analyzing leakage rates, piezometric variations, the discharge through the only spring in the area (the Fuentes de Marbella spring) and the physical-chemical characteristics of the aquifer water. Geological and structural aspects of the carbonate formation were also included. An alternative solution for water regulation in the river basin is proposed: the construction of a smaller dam downstream from the spring. This dam would induce recharge through the permeable base of the reservoir, raise the piezometric level and thus increase its storage capacity, as well as control and regulate the water discharged from the spring. 相似文献
15.
Sedat Türkmen Hidayet Tağa Eray Özgüler 《Geotechnical and Geological Engineering》2013,31(4):1137-1149
This paper covers the investigation of construction materials and selection of the dam type for the Büyük Karaçay Dam, which was planned to be constructed on Büyük Karaçay River 20 km to the SW of Hatay (Southern Turkey). The purposes of the dam are irrigation, domestic water supply, and producing energy. Auxiliary structures locations have been determined during the study of detailed geological maps of the dam axis and reservoir area. Quality, quantity and hauling distance of natural construction materials were effective to select different dam types. For engineering geological studies exploration boreholes were drilled at the dam site; pressuremeter tests were performed in order to determine bearing capacity and elasticity properties of rocks; pressured water tests were also performed to determine permeability of the dam site. Moreover, physical and mechanical properties of rocks were determined by the laboratory test. In the feasibility stage, the dam type was chosen as the central core rock-fill dam, depending on state of natural construction materials. In design stage dam type was changed as faced symmetrical hardfill dam. Finally, the dam type was revised again during the design stage as concrete face rockfill dam. 相似文献
16.
17.
水库岩溶渗漏及防渗研究综述 总被引：4，自引：0，他引：4
岩溶地区水库渗漏是可溶岩地区兴建水利枢纽的主要工程地质问题之一,尤其是在可溶岩广布、岩溶发育强烈、地形复杂地区,岩溶渗漏成为了该类地区水利水电工程的一个普遍问题.库区的岩溶渗漏不仅影响建坝后的正常蓄水,还将危及坝体的安全与稳定.因此,有必要对库区渗漏,特别是岩溶地区的库区渗漏进行渗漏机理、渗漏特征、渗漏条件等进行详细分... 相似文献
18.
Xiaolong Liu Siliang Li Zhongliang Wang Guilin Han Jun Li Baoli Wang Fushun Wang Li Bai 《中国地球化学学报》2017,36(4):667-679
Aquatic ecosystems have been identified as a globally significant source of nitrous oxide (N2O) due to continuous active nitrogen involvement, but the processes and influencing factors that control N2O production are still poorly understood, especially in reservoirs. For that, monthly N2O variations were monitored in Dongfeng reservoir (DFR) with a mesotrophic condition. The dissolved N2O concentration in DFR displayed a distinct spatial–temporal pattern but lower than that in the eutrophic reservoirs. During the whole sampling year, N2O saturation ranging from 144% to 640%, indicating that reservoir acted as source of atmospheric N2O. N2O production is induced by the introduction of nitrogen (NO3 ?, NH4 +) in mesotrophic reservoirs, and is also affected by oxygen level and water temperature. Nitrification was the predominate process for N2O production in DFR due to well-oxygenated longitudinal water layers. Mean values of estimated N2O flux from the air–water interface averaged 0.19 µmol m?2 h?1 with a range of 0.01–0.61 µmol m?2 h?1. DFR exhibited less N2O emission flux than that reported in a nearby eutrophic reservoir, but still acted as a moderate N2O source compared with other reservoirs and lakes worldwide. Annual emissions from the water–air interface of DFR were estimated to be 0.32 × 105 mol N–N2O, while N2O degassing from releasing water behind the dam during power generation was nearly five times greater. Hence, N2O degassing behind the dam should be taken into account for estimation of N2O emissions from artificial reservoirs, an omission that historically has probably resulted in underestimates. IPCC methodology should consider more specifically N2O emission estimation in aquatic ecosystems, especially in reservoirs, the default EF5 model will lead to an overestimation. 相似文献
19.