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.

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.

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.

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 Reducing Flood Risk using Computer System for Monitoring River Embankments

2017 ◽  
Vol 28 (3) ◽  
pp. 11-16 ◽  
Author(s):  
Monika Chuchro ◽  
Anna Franczyk ◽  
Barbara Bukowska-Belniak ◽  
Andrzej Leśniak
Keyword(s):  
Numerical Modelling ◽  
Computer Science ◽  
Water Level ◽  
Computer System ◽  
Sensor Data ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
The Real ◽  
Vertical Displacements ◽  
The Impact

AbstractIn order to learn about the phenomena occurring in flood embankment under the influence of external factors, including the increasing water level in the river during floods, a Computer System for Monitoring River Embankment (ISMOP) was developed using an experimental flood embankment. The project was carried out by a consortium consisting of AGH University of Science and Technology departments (Computer Science, Hydrogeology and Engineering Geology, Geoinformatics and Applied Computer Science and two companies (NEOSENTIO and SWECO Hydroprojekt Kraków) in co-operation with the Czernichów Community Council.An experimental flood embankment was built with two parallel sections with a length of 150 m and a height of 4.5 m, connected by a meandering, creating a reservoir that can be filled with water. For the construction of the embankment, different types of soils were used in all the five sections. Inside the flood embankment 1300 sensors are placed, including sensors for temperature, pore pressure, vertical displacements, as well as inclinometers. Also fiber optic strands, capable of measuring the temperature of the flood embankment on the upstream side, are located inside the experimental embankment [ismop.pl].Together with the real experiments, numerical modelling using the Itasca Flac 2D 7.0 was performed in order to describe the impact of water pressing on the flood embankment and the impact of increasing and decreasing reservoir water level on the phenomena that occur within the embankment.The results of modelling compared with the real sensor data allowed the evaluation of the current and future state of the embankment. Based on the data measured by the sensors and data received during the numerical modelling, a group of algorithms that allowed detection of anomaly phenomena was developed.

Fiber Bragg Grating Sensor for the Research of Water Level Measurement

2013 ◽  
Vol 823 ◽  
pp. 349-353
Author(s):  
Jie Hu ◽  
Qiu Ping Zhu ◽  
Min Li Zhao ◽  
Zhuo Yan Leng ◽  
Ting Cai ◽  
...  
Keyword(s):  
Water Level ◽  
Fiber Grating ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Level Measurement ◽  
Level Sensor ◽  
Elastomeric Membrane ◽  
Bragg Grating Sensor ◽  
Water Level Measurements ◽  
The Impact

In hydraulic engineering, hydrology and water conservancy departments focus on the water level measurements of reservoir. Water level sensor is very important to water level measurements of reservoir. This paper designs a water level sensor which is combined with elastomeric membrane and fiber grating, to eliminate the impact of temperature on the sensor through the use of self-compensating fiber grating and structural technology. The measurement of the water level sensor in the range of 0-5m tests the characteristics of the sensor and concludes the experimental curves of wavelength drift caused by water level after temperature compensation. Experimental results show that the performance of the sensor is good, that the accuracy is 0.5%, and that the resolution is 1cm and linearity is 0.999. Keywords: water level monitoring, fiber grating, sensing measurements

scholarly journals Analysis of the impact of Shifosi Reservoir water level on underground water

2018 ◽  
Vol 9 (2) ◽  
pp. 367-382 ◽  
Author(s):  
B. Yan ◽  
Y. Xie ◽  
C. J. Guo ◽  
C. S. Zhao
Keyword(s):  
Water Level ◽  
Groundwater Level ◽  
Underground Water ◽  
Drainage Ditches ◽  
Visual Modflow ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Reservoir Impoundment ◽  
The Right ◽  
The Impact

Abstract Shifosi Reservoir is a plain reservoir. High groundwater level in the nearby area caused by impoundment of the reservoir has not only submerged the nearby farmland and village, but also reduced production and affected farmers' living. To analyze the influence of reservoir impoundment on surrounding groundwater level, Visual MODFLOW software was used to simulate the groundwater in Zhujiapu and Chenpingpu areas on the right auxiliary dam of Shifosi Reservoir. Results show that with the rise of the reservoir water level from 45.5 m to 46.2 m and 46.5 m, the area under the critical groundwater table (45 m) in the study area decreased in turn. In 2008, when the reservoir water level was 46.2 m and 46.5 m, the area under the critical groundwater level was reduced by 0.64 km2 and 0.84 km2, respectively, compared with the case of reservoir water level of 45.5 m, and would decrease by 0.38 km2 and 0.45 km2, respectively, by 2022. This indicates that the impact of reservoir impoundment on groundwater level is great. Therefore, relief wells or drainage ditches should be arranged along the auxiliary dam axis to effectively lower the groundwater level, and improve the surrounding ecological environment of the reservoir.

scholarly journals The Monitoring-Based Analysis on Deformation-Controlling Factors and Slope Stability of Reservoir Landslide: Hongyanzi Landslide in the Southwest of China

Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Bing Han ◽  
Bin Tong ◽  
Jinkai Yan ◽  
Chunrong Yin ◽  
Liang Chen ◽  
...  
Keyword(s):  
Water Level ◽  
Water Pressure ◽  
Monitoring Program ◽  
Significant Risk ◽  
Controlling Factors ◽  
Seepage Water ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Reservoir Area ◽  
Reservoir Landslide

Reservoir landslide is a type of commonly seen geological hazards in reservoir area and could potentially cause significant risk to the routine operation of reservoir and hydropower station. It has been accepted that reservoir landslides are mainly induced by periodic variations of reservoir water level during the impoundment and drawdown process. In this study, to better understand the deformation characters and controlling factors of the reservoir landslide, a multiparameter-based monitoring program was conducted on a reservoir landslide—the Hongyanzi landslide located in Pubugou reservoir area in the southwest of China. The results indicated that significant deformation occurred to the landslide during the drawdown period; otherwise, the landslide remained stable. The major reason of reservoir landslide deformation is the generation of seepage water pressure caused by the rapidly growing water level difference inside and outside of the slope. The influences of precipitation and earthquake on the slope deformation of the Hongyanzi landslide were insignificant.

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