Construction Of Hydropower Stations Research Articles

Analyses of Runoff and Sediment Transport and their Drivers in a Rare Earth Mine Drainage Basin of the Yangtze River, China

A comprehensive analysis of the effects of major climate conditions such as El Nino Southern Oscillation (ENSO) and precipitation on changes in runoff and sediment transport in a basin may provide a scientific basis and technical support for regional water resource management and protection of the aquatic ecology. Taking the Taojiang River as an example, a large set of hydrogeographic data on runoff and sediment transport measured on a monthly basis from 1957 to 2015 was analyzed to study the impacts of various correlation factors on runoff and sediment transport in the river, which is located in the middle and lower reaches of the Yangtze River. Besides the conventional Mann–Kendall (M-K) method, cross-wavelet and wavelet coherence analysis methods were also applied in the data analysis. The results showed that: (1) From the M-K mutation tests conducted for the runoff volume and the sediment transport rate from 1957 to 2015, there were no significant changes in runoff. However, a mutation occurred in the sediment transport rate in 2005 and the average annual decrease reached 88.2237 million tons. (2) Precipitation was a dominant factor that controlled the changes in runoff volume and sediment transport rate. It directly influenced the changes in runoff volume, which subsequently caused the changes in sediment transport rate in the study area. Since the year 2005, sediment transport rates have been heavily influenced by the construction of large-scale hydro-power stations (Julongtan), causing a significant rate decline. A comparison between the sediment transport volume during 2005 to 2015 and that during 1980 to 2004 revealed that the annual sediment transport decrease reached 84.4079 million tons, accounting for 95.7% of the total decrease in sediment transport volume. (3) The significant resonance cycle between the sea surface temperature (SST) and the precipitation, runoff volume and sediment transport mainly occurred with a cyclic period between 1.33 and 5.33 years. During an ENSO event, the precipitation, runoff, and sediment transport rates all decreased at the beginning, then increased and reached their maximums, followed by a decline at the end.

Susceptibility mapping of damming landslide based on slope unit using frequency ratio model

In the mountainous area of southwest China, there is a large number of large hydropower stations that have already been built or under construction. The construction and the safety of the operation of hydropower stations directly affect the residents’ safety of life and property on both sides of the downstream river. Landslide hazards are one of the main problems affecting the construction and operation of hydropower stations. Therefore, it is currently more urgent to evaluate landslide susceptibility within the basin. The goal of this paper is to carry out landslide susceptibility mapping that affects the construction and operation of hydropower stations. In the case of a large research area and lack of landslide hazard data, this paper selects the sample of blocking river landslide in a larger area with similar topography and geological conditions and applies the quantitative method to carry out landslide sensitivity mapping. In this paper, the slope unit works as the evaluation unit, 191 landslide sample data were obtained, and nine landslide conditioning factors (slope, aspect, curvature, lithology, distance to fault, distance to the river, land use, soil, and the topographic wetness index (TWI)) were obtained. Combined with the quantitative frequency model (FR model), the landslide susceptibility map was obtained. The research process and results show that (1) when the study area is large, the landslide data is scarce, and it is difficult to get the landslide inventory map; the landslide samples can be selected in a larger area with similar topography and geological conditions. It is feasible to use the analysis data of landslide samples to evaluate the landslide susceptibility; (2) for specific industry applications such as hydropower station operation safety, the landslide evaluation range can be reduced by the spatial correlation between landslide aspect and river flow direction, which is beneficial to the management department to reduce the scope of attention; and (3) the verification results show that the slope unit can be used for quantitative evaluation of landslide sensitivity based on the FR model and can obtain the highest evaluation accuracy. The main advantage of this method is its capability to carry out landslide susceptibility mapping with quantitative methods and to ensure that higher mapping accuracy is obtained in areas where landslide hazard data is lacking.

Research on the Law of Stress and Strain Response of Surrounding Rock of Underground Powerhouse Cavity Excavated by Layered Cutting

As an important part of the construction of hydropower stations, underground powerhouses are increasingly perfected and synchronized with their construction methods. Layered cutting and excavation methods have emerged at the historic moment. This article takes Wendeng Pumped Storage Power Station as an example, using theoretical analysis, numerical simulation and other methods to study the influence of the layered cutting method on the change of stress and strain of surrounding rock, and draws the following conclusions: (1) The cave is from the first floor to the first during the eight-layer excavation, the tensile stress of the side walls on both sides is symmetrically distributed and there is a maximum on the same layer, and the compressive stress reaches the maximum at the bottom plate; with the increase in the number of excavation layers, the tensile stress on the side walls on both sides increases first and then decrease, the surrounding rock compression stress of the vault and floor continue to decrease. (2) During the excavation of the cavern, the strain of the vault on the same floor reaches the maximum value, and the strain continues to increase with the increase of the number of excavation layers. The excavation of the eighth floor has increased to 4.94mm; The strain changes less with the increase of the number of excavation layers, and is always maintained at 2.50~2.75mm; the floor strain decreases layer by layer. (3) By comparing the on-site monitoring and numerical calculation data, analyze the changing trend of the on-site measured arch strain and the side wall stress around 2.50mm up and down, and calculate the difference ratio between the numerical simulation and the measured data. The excavation time difference ratio reaches the maximum value of 29.1%, which verifies the correctness of the simulation experiment and provides a supporting scheme for the underground powerhouse in harmony with the deformation law.

Influence of hydropower stations on the water microbiota in the downstream of Jinsha River, China

Construction of hydropower stations has been an important approach to meet China’s increasing power demand, but the impact of construction of hydropower stations on river microbiota is not fully understood. To evaluate this, the microbial composition from 18 sampling sites in the downstream of Jinsha River of China, upstream and downstream of two completed and two under-construction hydropower stations, were analyzed using high-throughput 16S rRNA gene sequencing. Three independent samples from each site were analyzed. A total of 18,683 OTUs from 1,350 genera were identified at 97% sequence similarity. Our results showed that the completion of hydropower stations would significantly increase the relative abundances of Acidobacteria, Chlorobi, Chloroflexi, Cyanobacteria, Nitrospirae, and Planctomycetes, especially the relative abundance of Synechococcus dOTUs and thus increase the risk of algal blooms. PCA based on all KEGG pathways and the significantly different KEGG pathways showed the predicted metabolic characteristics of the water microbiota by PICRUSt in the activated hydropower station group were significant difference to the other groups. Results from canonical correspondence analysis showed that water temperature and dissolved oxygen had significant effects on microbiota composition. These results are important for assessing the impact of hydropower stations on river microbiota and their potential environmental risks.

Attention to Environmental Protection of Small Hydro-power Stations

In this paper, some problems commonly encountered in the construction and production process of small hydro-power stations in China are analyzed and explained, and the solutions are provided as well. Existing problems we have are the shortage of Eco-flow discharge, the Oil pollution in downstream river course caused by power generation production at the station, the cooling water supply of hydro-power station and the problem of eliminating pollution, electromagnetic and noise pollution of station, the resident's dispute around the power station caused by the increase and decrease of the groundwater level at the location of the station, the flood control problem of the water diversion hub, the pollution of the river channel, and the danger caused by the height of trees under the transmission line. The author, who based on many years of practical experience in hydro-power stations, and combined with relevant state policies and regulations, and puts forward practical methods and ideas to solve the problem in close connection with the actual situation of the project.

Spatial characteristics of total phosphorus loads from different sources in the Lancang River Basin

Lancang River, the upstream reach of Mekong River, is a hotspot region in the sustainable management of water resources and environment as it is currently facing the deterioration of aquatic ecosystems. Nutrient balance (i.e., Phosphorus) in the Lancang-Mekong River Basin has become a highly disputed issue in recent years due to the construction of cascade hydropower stations. However, the estimation of the total phosphorus (TP) load faces great difficulties and challenges due to the absent measured water quality data. This study estimates the TP load based on the social economic data, analyzes the spatial distribution of TP and the contribution of different TP sources in the Lancang River basin under the level of social-economic development in 2014. Results show that the annual average TP load in the Lancang River Basin is 1.6 × 104–3.9 × 104 tons, which is at a very low level compared with other large-scale basins in China. The TP load from natural soil erosion dominates all other sources, accounting for 69%, followed by agricultural production and fertilization. In general, the TP load increases from upstream to downstream, but heterogeneity also exits in different regions under the influence of various factors, such as rainfall intensity, soil properties and human activities. The results reveal a holistic picture of TP load in the Lancang River Basin, which could provide a new perspective on the trans-border international river management.

The spatial granularity effect, changing landscape patterns, and suitable landscape metrics in the Three Gorges Reservoir Area, 1995–2015

Abstract The Three Gorges Project (TGP) is a mega-water conservancy and hydropower project that have attracted worldwide attention. Under the influence of human activities, the landscape pattern has changed greatly. Using landscape metrics to analyze landscape pattern changes is the critical to understanding landscape pattern and ecological process. In this study, Landsat TM/ETM+/OLI images are used to extract indices for area edge, shape, spatial distribution, and diversity. Additionally, 19 landscape indices are taken to scale the granularity of the landscape level and the class level. An analysis of appropriate size is used to quantify the response of landscape indices to change landscape patterns during the four stages and a Crosstab model is used for pattern presentation. Finally, landscape indices are analyzed utilizing of Pearson correlation method to identify the landscape indicators suitable for the Three Gorges Reservoir. We have found that both the class level and landscape level indices are sensitive to grain size changes. Our results suggest that the suitable grain size is 30–60 m. Furthermore, the indicators suitable applied to analyzing changes in the landscape patterns in the TGR are Class Area (CA), Number of Patch (NP), Largest Patch Index (LPI), Landscape Shape Index (LSI), Effective Mesh Size (MESH), and Patch Density (PD). The main reasons for the change of landscape pattern in the Three Gorges Reservoir are land consolidation project, returning farmland to forest project, nature reserve construction, hydropower station construction and urbanization development.

Variation of alpine lakes from 1986 to 2019 in the Headwater Area of the Yellow River, Tibetan Plateau using Google Earth Engine

To understand the variations in surface water associated with changes in air temperature, precipitation, and permafrost in the Headwater Area of the Yellow River (HAYR), we studied the dynamics of alpine lakes larger than 0.01 km2 during 1986–2019 using Google Earth Engine (GEE) platform. The surface areas of water bodies in the HAYR were processed using mass remote sensing images consisting of Landsat TM/ETM+/OLI, Sentinel-2A, and MODIS based on automatic extraction of water indices under GEE. Besides, the lake ice phenology of the Sister Lakes (the Gyaring Lake and the Ngöring Lake) was derived by threshold segmenting of water/ice area ratio. Results demonstrate that the change of surface areas experienced four stages: decreasing during 1986–2004, increasing during 2004–2012, decreasing again during 2012–2017, and increasing again during 2017–2019. Correspondingly, the number of small lakes decreased (−26.5 per year), increased (139.5 per year), again decreased (−109.0 per year), and again increased (433.0 per year). Eight lakes larger than 1 km2 disappeared in 2004 but restored afterward. The overall trends in the area of small lakes (0.01–1 km2), large lakes (>1 km2), and all lakes during 1986–2019 were 0.4, 3.1, and 3.4 km2 per year, respectively. Although the onsets of freezing, freeze-up, breaking and the break-up of the Sister Lakes varied from year to year, there is no obvious trend regarding the lake ice phenology. Tendencies of lake variations in the HAYR are primarily related to the increased net precipitation and the declined aridity, followed by the construction of hydropower station around the outlet of the Ngöring Lake, as well as permafrost degradation.

Effect of river damming on phosphorus retention in China

The construction of hydropower stations not only improves water conservancy and hydropower generation, but also seriously hinders the natural biogeochemical circulation of rivers, resulting in phosphorus retention in reservoirs, eutrophication of water bodies, and finally phosphorus pollution. Therefore, it is of great significance to study the effect of phosphorus retention in the closure of dams of hydropower stations.In order to solve this problem, this paper, based on the global news model, simulated the retention of phosphorus in eight dams and reservoirs in China.The results showed that :(1) phosphorus production was higher in the densely populated and economically developed basins along the southeast coast of China, among which the phosphorus production was highest in the Yangtze river basin and the pearl river basin, reaching 139 kg/(km2· yr) and 161 kg/(km2· yr), respectively.(2) China’s dams are mainly built in the middle and lower reaches of the Yangtze river, which is closely related to the rich water resources and the developed regional economy.It is worth mentioning that the dams with the highest phosphorus retention are also located on the major rivers of the Yangtze, Yellow and Huai rivers.In general, the areas with high phosphorus retention are mainly concentrated in central and southern China.Population, economy, latitude, area, runoff and other factors will be the key factors to determine phosphorus retention.

Climatic and anthropogenic impacts on water and sediment generation in the middle reach of the Jinsha River Basin

AbstractResponse of water and sediment generation to climate change and anthropogenic activities is becoming a hot topic in the middle reach of the Jinsha River Basin. In this research, coefficients of variation and concentration degree (i.e., Cv and Cd) and double mass curve (DDC) were adopted to examine the changes in water and sediment discharge and their relationships with precipitation. The contribution rates of climatic and anthropogenic factors to water and sediment discharge were assessed through comparisons between the measured and predicted values in the baseline and postbaseline periods in the basin. The main results were: (a) the water and sediment discharges of the basin showed a decreasing trend from 2006 to 2014, with peak points of Cv and Cd of sediment discharge of the basin in 2009 and 2010, respectively; (b) the precipitation had a major influence on water discharge variations, and the peak point of the DDC of the cumulative precipitation and sediment discharge was consistent with the cumulative water and sediment discharge; and (c) under annual and flooding season scales, the contribution rates of anthropogenic factors to water discharge were 63.060% and 70.457%, respectively. The contribution rates of anthropogenic factors on sediment discharge were 84.790% and 85.541%, respectively. The impacts of anthropogenic factors on water and sediment discharge were more significant than the impacts of precipitation, in which the construction and operation of cascade hydropower stations (CHS) were believed to play a crucial role.

银江水电站建设对库区水环境的影响预测

银江水电站建设对库区水环境的影响预测

Cumulative Environmental Effects of Hydropower Stations Based on the Water Footprint Method—Yalong River Basin, China

The construction of hydropower stations is not without controversy as they have a certain degree of impact on the ecological environment. Moreover, the water footprint and its cumulative effects on the environment (The relationship between the degree of hydropower development and utilization in the basin and the environment) of the development and utilization of cascade hydropower stations are incompletely understood. In this paper, we calculate the evaporated water footprint (EWF, water evaporated from reservoirs) and the product water footprint of hydropower stations (PWF, water consumption per unit of electricity production), and the blue water scarcity (BWS, the ratio of the total blue water footprint to blue water availability) based on data from 19 selected hydropower stations in the Yalong River Basin, China. Results show that: (a) the EWFs in established, ongoing, proposed, and planning phases of 19 hydropower stations are 243, 123, 59, and 42 Mm3, respectively; (b) the PWF of 19 hydropower stations varies between 0.01 and 4.49 m3GJ−1, and the average PWF is 1.20 m3GJ−1. These values are quite small when compared with hydropower stations in other basins in the world, and the difference in PWF among different hydropower stations is mainly derived from energy efficiency factor; (c) all the BWS in the Yalong River Basin are below 100% (low blue water scarcity), in which the total blue water footprint is less than 20% of the natural flow, and environmental flow requirements are met. From the perspective of the water footprint method, the cumulative environmental effects of hydropower development and utilization in the Yalong River Basin will not affect the local environmental flow requirements.

Experimental study on the influence of river flow confluences on the open channel stage–discharge relationship

ABSTRACTAccurate assessment of stage–discharge relationships in open channel flows is important to the design and management of hydraulic structures and engineering. Flow junctions commonly occur at the confluence of natural rivers or streams. The effect of flow junctions on the stage–discharge relationship at mountain river confluences was found by measuring velocity fields and water levels in experimental models. The results show that the backwater and accumulation–separation at flow junctions affect the flow structures and patterns in the channel; also, flow confluences may induce complex flow characteristics of backwater and flow separation at river junctions, indicating potential submerged flooding disasters within the confluence zone. The impacts of flow junctions on the stage–discharge relationship are investigated for two physical confluence models built from river confluence prototype systems in southwest China. The results show that the presence of tributary river inflows tends to increase the water level of the main river. This is important for flood control, flood-risk evaluation and engineering (e.g. hydropower station construction) in mountain rivers. Finally, a comparative quantitative analysis based on flow motion equations is conducted to evaluate the stage–discharge relationship in both uniform and regular confluence systems. The results indicate that more accurate prediction can be made when taking into account the flow non-uniformity induced by flow separation, backwater and distorted bed in the junction region.

On directions of improving the energy efficiency in Russia

AnnotationThe paper analyzes the structure of the energy balance of the Russian Federation for power systems, draws conclusions on the impact of HPPs in the structure of electricity generation on the price of electricity for ultimate customers. The influence of the construction of new hydropower stations on the development of waterways is considered.

Analysis of the change impact in the share of generation from HPPs in the structure of the unified power system energy balance to residential tariff

AnnotationThe paper analyzes the structure of the energy balance of the Russian Federation for power systems, draws conclusions on the impact of HPPs in the structure of electricity generation on the price of electricity for ultimate customers. The influence of the construction of new hydropower stations on the development of waterways is considered.

A Method for Rockburst Prediction in the Deep Tunnels of Hydropower Stations Based on the Monitored Microseismicity and an Optimized Probabilistic Neural Network Model

Hydropower is one of the most important renewable energy sources. However, the safe construction of hydropower stations is seriously affected by disasters like rockburst, which, in turn, restricts the sustainable development of hydropower energy. In this paper, a method for rockburst prediction in the deep tunnels of hydropower stations based on the use of real-time microseismic (MS) monitoring information and an optimized probabilistic neural network (PNN) model is proposed. The model consists of the mean impact value algorithm (MIVA), the modified firefly algorithm (MFA), and PNN (MIVA-MFA-PNN model). The MIVA is used to reduce the interference from redundant information in the multiple MS parameters in the input layer of the PNN. The MFA is used to optimize the parameter smoothing factor in the PNN and reduce the error caused by artificial determination. Three improvements are made in the MFA compared to the standard firefly algorithm. The proposed rockburst prediction method is tested by 93 rockburst cases with different intensities that occurred in parts of the deep diversion and drainage tunnels of the Jinping II hydropower station, China (with a maximum depth of 2525 m). The results show that the rates of correct rockburst prediction of the test samples and learning samples are 100% and 86.75%, respectively. However, when a common PNN model combined with monitored microseismicity is used, the related rates are only 80.0% and 61.45%, respectively. The proposed method can provide a reference for rockburst prediction in MS monitored deep tunnels of hydropower projects.

Sectoral Cooperation of the BRICS Countries: Potential and Implementation Priorities

The BRICS countries are increasingly expanding multilateral forms of cooperation, moving beyond political areas to economic ones. This cooperation is based on their interest in using the resources and experience of other partners to the group to develop national economies and promote the export of goods, technologies and services for the benefit of national producers. The purpose of the study is to analyse the potential and identify the most promising areas of sectoral cooperation. It was carried out using the methods of comparative and statistical analysis, historical analogies, deductive and expert assessments. Agreed at BRICS summits, national economic strategies set the priorities of sectoral cooperation. Raising the competitive capacity of the BRICS economies is considered today in the context of productivity enhancement, including increasing energy efficiency, improving logistics, innovating technologies. The most promising areas are cooperation in offshore oil and gas production, nuclear power, construction of small hydropower stations, building transport corridors, including the high-speed networks and equipment of the Northern Sea Route. The sectoral priorities also highlight cooperation in the agriculture sector to address food security problems and in the digitisation of all sectors of the economy to take advantage of the opportunities provided by information and communication technologies.

Sensitivity analysis of toppling deformation for interbedded anti-inclined rock slopes based on the Grey relation method

Toppling deformations generally develop in interbedded anti-inclined rock slopes in the upper reaches of the Yalong River in southwest China. With the characteristics of large scales, strong deformation degrees and complex deformation modes, toppling bodies may eventually lead to instability failure in the form of landslides, which seriously threaten the construction and operation of hydropower stations in the basin. Taking three typical examples of toppling failures for interbedded anti-inclined rock slopes in the basin, the sensitivity analysis of 19 impact factors affecting the toppling deformation of this type of slope is obtained via the Grey correlation method and UDEC. The results show that the geometric parameters represented by slope angles are the most sensitive to toppling deformation, the mechanical parameters of joints are more sensitive to toppling deformation than the physical and mechanical parameters of intact rocks, and the sensitivities of the parameters of sandstone and slate gradually converge in the deformation process.

Seepage Characteristics and Its Control Mechanism of Rock Mass in High-Steep Slopes

In Southwest China large-scale hydropower projects, the hydraulic conductivity and fracture aperture within the rock mass of a reservoir bank slope has dramatically undergone a time series of evolution during dam abutment excavation, reservoir impounding and fluctuation operation, and discharge atomization. Accordingly, seepage control measures by hydro-structures such as drainage or water insulation curtains should be guided by scientific foundation with a dynamic process covering life-cycle performance. In this paper, the up-to-date status of studying the evolution mechanism of seepage characteristics relating to fractured rock hydraulics from experimental samples to the engineering scale of the rock mass is reviewed for the first time. Then, the experimental findings and improved practice method on nonlinear seepage flow under intensive pressure drives are introduced. Finally, the scientific progress made in fractured rock seepage control theory and optimization of the design technology of high-steep slope engineering is outlined. The undertaken studies summarized herewith are expected to contribute to laying a foundation to guide the further development of effective geophysical means and integrated monitoring systems in hydropower station construction fields.

SMALL HYDROPOWER PLANTS AS A PART OF ELECTRIC POWER INDUSTRY AND ENERGY MARKET OF UKRAINE

Globalization and sustainable development necessitate joint analysis of technological and environmental trends in energy development taking into account current economic and legal provisions. Based on synthesis of the current state of Ukrainian electric power system in general and hydropower in particular, there have been underscored the importance of comprehensive approach in identifying the key tasks of building the pathway of further electric power industry development. The authors provide the characteristics of today’s organizational and technological structure of the electric power system, including the legal provisions regulating its activity. As currently there are significant legislative changes, particular attention was paid to the review of electricity market. Features of the new liberalized electricity market have been determined in comparison with the current market, and also in connection with renewable energy characteristics. Thus, amendments introduced by the new Law “On electricity market” to the green tariff policy have been detailed with the regard to incentive mechanism for development of renewable energy and liability of electricity producers operating under Green Tariff for imbalances. The article focuses on the analysis of the state and growth potential of small hydropower. Еconomic incentives are systematized according to the current legislation. Also, here is presented the potential for possible growth of small hydropower, namely, quantitative result of the exploration of the technical potential of hydropower resources of small rivers. There have been identified a number of barriers and impediments to the construction of small HPPs. Environmental restrictions to the construction of small hydropower stations have been formulated according to the accurate analysis of various branches of national legislation such as the Land Code, the Water Code, the Law “On the Nature Reserve Fund of Ukraine”, etc., as well as valid ratified documents and other key soft-low instruments at the international level. Additionally, provisions of Сustoms and Tax legislation on small hydropower regarding to incentives for technology development have been defined. Consideration of small hydropower projects successfully implemented on the territory of the country confirms the possibility of the future development of small hydropower.