Monitoring Model for Dam Seepage Based on Lag Effect

2013 ◽  
Vol 353-356 ◽  
pp. 2456-2462 ◽  
Author(s):  
Shao Wei Wang ◽  
Teng Fei Bao
Keyword(s):  
Water Level ◽  
Daily Variation ◽  
Level Variation ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Water Level Variation ◽  
Monitoring Model ◽  
Lag Effect ◽  
Monitoring And Forecasting ◽  
The Impact

The traditional dam seepage monitoring model is based on the relationship of seepage elements with the upstream reservoir water level and rainfall, which includes the impact of base value, this model will weaken the effects of reservoir water level variation and rainfall on the variation of seepage elements, especially under the condition of high reservoir water level and smaller head fluctuation, so components separated by this model are not normally the practical. Based on the theory of unsteady seepage, the lag effect function has been introduced into the seepage monitoring model to take the lag effect of reservoir water level variation and rainfall into account, and the daily variation monitoring model of dam seepage elements is established. Case studies are in good agreement with original observations, so the proposed model can be used in the daily variation monitoring and forecasting of dam seepage elements.

scholarly journals Limitation of the Reservoirs’ Water Level Alteration Rate in Hydro Electric Power Stations Operational Mode Control in Accordance with Safety Rules for Water Work Facilities

2012 ◽  
pp. 65-73
Author(s):  
Keyword(s):  
Electric Power ◽  
Water Level ◽  
Electric Power Station ◽  
Operational Mode ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Water Power ◽  
Power Stations ◽  
The Impact ◽  
Water Work

The impact of the reservoir water level alterations rate limitation upon its operational mode has been studied. These limitations impact upon the hydro electric power station performance has been assessed. It has been proposed to take into consideration the level alteration rate in water/economic and water/power production calculations.

Deformation and stability analyses of a near-dam rocky slope and its potential landslide-generated wave threats

2021 ◽  
pp. qjegh2021-018
Author(s):  
Ming-liang Chen ◽  
Xing-guo Yang ◽  
Shun-chao Qi ◽  
Hai-bo Li ◽  
Jia-wen Zhou
Keyword(s):  
Water Level ◽  
Rock Slope ◽  
Limit Equilibrium ◽  
Water Levels ◽  
Reservoir Rock ◽  
Water Diversion ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
The Impact

Occurrence of a reservoir landslide and its potential secondary hazards near a dam can result in significant losses and casualties, such as those that resulted from the Vajont landslide. In this study, a cataclinal rock slope in the Maoergai reservoir was taken as a case to study the characteristics of the gravitational deformation process and to analyze the potential threat. The stability of rock slope is analyzed by the limit equilibrium method, and the potential landslide movement and subsequent waves are also simulated. Results indicate that lithology, geological structure, reservoir water level changes and artificial activities all play an important role for the large deformation of rock slope deformation, which is characterized by a combination of bending-toppling and principally shear-slip. Pre-calculations of potential threats indicated that the impact of a landslide wave would be greater at dead water levels than at the normal water level and could result in blockage of the inlet to the water diversion structure on the opposite right bank. These findings provide implication for the control of reservoir rock slopes: (i) serious attention should be paid to the influence of water on rock strength in early and (ii) infiltration must be prevented during water level rise.Thematic collection: This article is part of the Role of water in destabilizing slopes collection available at: https://www.lyellcollection.org/cc/Role-of-water-in-destabilizing-slopes

scholarly journals The Impact of Microearthquakes Induced by Reservoir Water Level Rise on Stability of Rock Slope

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Dongliang Li ◽  
Xinrong Liu ◽  
Xingwang Li ◽  
Yongquan Liu
Keyword(s):  
Water Level ◽  
Shear Failure ◽  
Middle Part ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Water Level Rise ◽  
Soft Interlayer ◽  
Tensile Fractures ◽  
The Stability ◽  
The Impact

In order to study the impact of frequent microearthquakes induced by water level rise on the stability of rock bedded slopes in the Three Gorges Reservoir (TGR) area, Zhaoshuling Landslide (a representative slope) is selected to study. Safety factors based on probability statistics andFLAC3Dare used for numerical simulation (under the operating condition that five earthquakes of Intensity IV are applied to slope in succession after water level rises from 145 m to 175 m). Then the slope’s dynamic stability characteristics and failure mechanism are analyzed. The study shows that slope deformation is evidently the result of thrust load. The deformation starts from the steeply dipping segment in the middle part of slip mass and is controlled by the soft interlayer. Shear failure tends to occur along the soft interlayer and the horizontal slip displacement increases from the rear to the front of the slope. The steeply dipping segment shows a general downslide trend. Although the gentle slope platform on the rear edge is relatively stable, it is vulnerable to tensile fractures which are precursors of landslide. Under the same failure probability, as the number of microearthquake occurrences increases, the safety factor of slope under microearthquake action decreases gradually.

Study on Relationship between Deformation of Reservoir Water Level Fluctuation Change of the Shuping Landslide

2014 ◽  
Vol 556-562 ◽  
pp. 881-884
Author(s):  
Xue Qing Yan ◽  
Zong Hua Zhou ◽  
Peng Fei Tu
Keyword(s):  
Water Level ◽  
General Rule ◽  
Water Level Fluctuation ◽  
Level Fluctuation ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Water Level Variation ◽  
The Three Gorges ◽  
Landslide Deformation ◽  
Reservoir Water Level Fluctuation

The change of reservoir water level fluctuation has an important influence on the landslide deformation. In this paper, taking Zigui County of the Three Gorges Reservoir Shuping landslide as an example, based on the deformation and water level of reservoir deformation related analysis of landslide, summarizes the general rule by reservoir water level variation effect on deformation of landslide, which can provide some reference for the monitoring and analysis of landslide similar.

scholarly journals Use of Time-Series NDWI to Monitor Emerging Archaeological Sites: Case Studies from Iraqi Artificial Reservoirs

2021 ◽  
Vol 13 (4) ◽  
pp. 786
Author(s):  
Andrea Titolo
Keyword(s):  
Time Series ◽  
Water Level ◽  
Satellite Image ◽  
Archaeological Site ◽  
Archaeological Sites ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Medium Resolution ◽  
A Site ◽  
The Impact

Over the last 50 years, countries across North Africa and the Middle East have seen a significant increase in dam construction which, notwithstanding their benefits, have endangered archaeological heritage. Archaeological surveys and salvage excavations have been carried out in threatened areas in the past, but the formation of reservoirs often resulted in the permanent loss of archaeological data. However, in 2018, a sharp fall in the water level of the Mosul Dam reservoir led to the emersion of the archaeological site of Kemune and allowed for its brief and targeted investigation. Reservoir water level change is not unique to the Mosul Dam, but it is a phenomenon affecting most of the artificial lakes of present-day Iraq. However, to know in advance which sites will be exposed due to a decrease in water level can be a challenging task, especially without any previous knowledge, field investigation, or high-resolution satellite image. Nonetheless, by using time-series medium-resolution satellite images, combined to obtain spectral indexes for different years, it is possible to monitor “patterns” of emerging archaeological sites from three major Iraqi reservoirs: Mosul, Haditha and Hamrin lake. The Normalised Difference Water Index (NDWI), generated from annual composites of Landsat and Sentinel-2 images, allow us to distinguish between water bodies and other land surfaces. When coupled with a pixel analysis of each image, the index can provide a mean for highlighting whether an archaeological site is submerged or not. Moreover, using a zonal histogram algorithm in QGIS over polygon shapefiles that represent a site surface, it is possible to assess the area of a site that has been exposed over time. The same analyses were carried out on monthly composites for the year 2018, to assess the impact of monthly variation of the water level on the archaeological sites. The results from both analyses have been visually evaluated using medium-resolution true colour images for specific years and locations and with 3 m resolution Planetscope images for 2018. Understanding emersion “patterns” of known archaeological sites provides a useful tool for targeted rescue excavation, while also expanding the knowledge of the post-flooding impact on cultural heritage in the regions under study.

Geomechanics Study on the Influence of Water Level Variation on Landslide Safety in Three Gorges Reservoir Region

2014 ◽  
Vol 540 ◽  
pp. 181-184
Author(s):  
Dong Fang Tian
Keyword(s):  
Water Level ◽  
Three Gorges Reservoir ◽  
High Water ◽  
Three Gorges ◽  
Level Variation ◽  
Water Level Variation ◽  
Three Gorges Reservoir Region ◽  
Influence Of Water ◽  
The Impact ◽  
Dangerous Condition

Up concave and linear slices are two basic geometric shapes of the landslides. In this paper, the unsaturated seepage fields of landslides are described by Richards’s equation and the safety of landslides are calculated by the Morgenstern-Prince method. The Influences of water level variation on landslide safety in Three Gorges reservoir region are discussed through two landslides. It indicates that,the impact of buoyancy is significant and related closely to water level change, and the most dangerous condition is stable high water level. To the slide which slice is line, the impact of permeation is significant and related closely to water change too, and the most dangerous condition is at the beginning of reaching the low water level.

scholarly journals Numerical Analysis of Slope Stability under Reservoir Water Level Fluctuations Using a FEM-LEM-Combined Method

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Qingxiang Meng ◽  
Kun Qian ◽  
Lin Zhong ◽  
Jinjian Gu ◽  
Yue Li ◽  
...  
Keyword(s):  
Slope Stability ◽  
Water Level ◽  
Large Scale ◽  
Numerical Study ◽  
Soil Strength ◽  
Water Levels ◽  
Water Level Fluctuations ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
The Impact

Large-scale slopes at the banks of reservoirs pose a serious threat to the safety of hydropower stations. The fluctuation of the reservoir water level is a key factor in the slope stability. However, the parameters to describe the relationship among water content, matric suction, and soil strength are difficult to measure using unsaturated soil strength theory. To solve this problem, a simple FEM-LEM-combined scheme considering pore pressure, seepage force, and strength weakening is presented to calculate the safety factor. A numerical study on the impact of reservoir water level fluctuations on stability of a glaciofluvial deposit slope is implemented. Two typical profiles are used to estimate the stability of the glaciofluvial deposit slope in response to rising and lowering water levels. The results indicate that this method proposed a simple and efficient tool for water level-induced slope stability analysis.

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