Dams In India Research Articles

Analysis of seismic damage process of high concrete dam-foundation system

In the anti-seismic analysis of concrete high dams, only the damage cracking of the dam concrete is usually considered, and the nonlinear characteristics of the dam foundation rock during the earthquake are not considered. Taking the Koyna gravity dam in India and Shapai arch dam in China as examples, this paper adopts the nonlinear time-history analysis method and takes into account the comprehensive influence of the radiation damping of infinite foundation, the hydrodynamic interaction between dam and reservoir, the nonlinear dynamic contact between various joints in the dam body and foundation, and the damage of dam concrete and foundation rock mass in the damage evolution process, analyzes damage evolution process of dam body-foundation system under earthquake action and the influence of foundation rock mass damage on seismic failure mode of concrete dam-foundation system, and compares the numerical simulation results with the actual earthquake situation. The calculation results show that after considering the damage of the dam foundation rock mass, the rock mass of the dam heel firstly appears to be damaged under the action of the earthquake and gradually expands into the interior of the foundation. The dam heel and the foundation surface are not damaged. The numerical simulation results are more in line with the actual situation of earthquake.

Height–Area–Storage Functional Models for Evaporation-Loss Inclusion in Reservoir-Planning Analysis

Reservoir planning without the explicit accommodation of evaporation loss leads to errors in capacity estimates. However, whenever evaporation loss is considered, its quantification uses linear approximations of the intrinsically nonlinear height–area–storage (H–A–S) relationship to estimate the reservoir area, leading to bias in capacity estimates. In this work, biases resulting from using various H–A–S models are evaluated. These models include linear and nonlinear functions, either specifically developed for the case-study sites or available in the Global Reservoir and Dam (GRanD) database. All empirically derived approximations used data for two dams in India: the Bhakra on Sutlej River and the Pong on the Beas River, both tributaries of the Indus River. The results showed that linear H–A–S models underestimate the exposed surface area of the Pong reservoir by up to 11.19%; the bias at Bhakra was much less. The GRanD H–A–S model performed very poorly at both reservoirs, producing overprediction in exposed reservoir area of up to 100% and 415% at the Pong and Bhakra reservoirs, respectively. Analyses also showed that up to 29% increase in reservoir capacity is required to compensate for the effect of net evaporation loss at low demand levels. As demand increases, the required evaporation-correction capacity decreases in proportional terms and is indistinguishable for all H–A–S models. Finally, recommendations are made on using the results for evaporation adjustment at nongauged sites in the region.

Human risk assessment of Panchet Dam in India using TOPSIS and WASPAS Multi-Criteria Decision-Making (MCDM) methods

Every river dam activity has definite beneficial effects but cannot circumvent its negative impact in the long run. The Panchet dam has been commissioned as a multipurpose river valley project under the authority of Damodar Valley Corporation (DVC) across the river Damodar at the border of West Bengal and Jharkhand states of India in 1959 to overcome some problems like flood control, supply of irrigation, domestic and industrial water, hydroelectric power generation etc. But it has now become a threat to the surrounding people, due to rapid sedimentation and reduction in its water holding capacity. Human risk assessment of the dam thus claims importance and such an effort is executed in this work using Delphi Questionnaire and two Multi-Criteria Decision-Making (MCDM) methods viz. Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) and Weighted Aggregated Sum Product Assessment (WASPAS). At first 9 human risk alternatives (A1-A9) of the dam are identified using Delphi Questionnaire and rated them in order to prioritize using TOPSIS and WASPAS methods. Risk prioritization results of TOPSIS and WASPAS show somewhat differences. The integrated ‘Mean-Rank’ method is applied to provide final priority ranking of the risk alternatives and the result is: A3 > A9 > A8 > A4, A6 > A1 > A7 > A5 > A2 (when WASPAS parameter λ = 0); A3 > A9 > A4, A8 > A2 > A6 > A1 > A5, A7 (when WASPAS parameter λ = 1); A3 > A9 > A8 > A4, A6 > A1 > A2 > A5 > A7 (when WASPAS parameter λ = 0.5). In all cases, A3 (Population Displacement) alternative ranks first and is identified as the top most risk prone alternative among all. The risk of displacement of people due to further inundation of land is rising gradually. This has motivated us for assessment of other human risks of the dam in the work.

Finite element-based probabilistic stability analysis of rock-fill tailing dam considering regional seismicity

The recent tailing dam failure in Brazil has again emphasized the need of performing robust stability analysis prior to construction. This paper demonstrates the probabilistic dynamic stability analysis of tailing dams considering an existing rock-fill tailing dam in India. The stability analysis was performed using 2D finite element-based package RS2. In the probabilistic analysis, the strength parameters such as cohesion (c) and the friction angle (φ) were considered as random variables. In total, 3000 numbers of samples were generated assuming a normal distribution. Monte Carlo simulation was used to evaluate the probability of failure (PoF) and reliability index. Strength reduction method was used for the finite element analyses. A pseudo-static seismic loading was incorporated in the strength reduction analysis to check the seismic stability of the dam. A factor of safety (FoS) of 1.15 was observed from the deterministic analysis for downstream slope. For the same case, the probabilistic analysis provided a mean FoS of 1.19 with 5.46% probability of failure. The FoS values and the locations of the critical failure surface obtained by the limit equilibrium method and finite element method were compared. The observed FoS values were found to be higher than the values specified in the IS 7894-1975 (reaffirmed in 1997) and ANCOLD (1999). In the case of pseudo-static approach, the maximum displacement of 0.53 m was observed in the slope. Furthermore, nonlinear dynamic stability analysis was performed to simulate a true earthquake event. The permanent deformation of the slope after the earthquake was found to be 0.40 m. The zone of failure observed in both pseudo-static and nonlinear dynamic stability analyses was found to be the same. Overall, the results revealed that the spatial variability of the soil significantly influences the FoS values.

Nation’s body, river’s pulse: Narratives of anti-dam politics in India

In the 1990s, social movements against large dams in India were celebrated for crafting a powerful challenge to dominant policies of development. These grounded struggles were acclaimed for their critique of capitalist industrialization and their advocacy for an alternative model of socially just and ecologically sustainable development. Twenty years later, as large dams continue to be built, their critics have shifted the battle off the streets to new arenas – to courts and government committees, in particular – and switched to a techno-managerial discourse of maintaining river health. What accounts for this change? This article traces the trajectory of cultural politics around Indian rivers within the larger imagination of the nation, the rise of economic liberalization and Hindu nationalism, and the emergence of environmental bureaucracies. It argues that, alongside being shaped by this context, current anti-dam campaigns also contend with the legacy of earlier social movements, their gains as well as losses. This political field has narrowed the potential for radical critique, large-scale collective mobilization and, ultimately, keeping rivers alive.

Changing landscape and ecotourism development in a large dam site: a case study of Tehri dam, India

ABSTRACTThis paper presents an analysis of the historical change in the local landscape of Tehri dam, the highest earth and land filled dam in India, and surroundings focusing on changes that transpired due to dam construction. Based on the qualitative data collected using interviews and participant observation, past changes in physical, economic, and social landscapes were examined from the perspective of displaced populations. The transformation involved the initial emergence of energy landscape followed by the recent development of tourist landscape in the region. This emerging tourist landscape from the existing energy landscape was found to be promising for the local economy and potential tie point for social and cultural life. Persistent efforts on part of locals, tourists, and government can effectively enhance ecotourism. There is a need of understanding the current and future landscapes in light of past, evolving the therapeutic dimensions of natural landscape.

Seismic Improvement of Gravity Dams Using Isolation Layer in Contact Area of Dam–Reservoir in Smeared Crack Approach

This study has been conducted to evaluate the effect of the isolation layer on the seismic improvement of concrete gravity dams considering dam–reservoir interaction. Koyna dam in India, due to both horizontal and vertical components of Koyna earthquake, is modeled as a case study to show the effect of the upstream isolation layer on the seismic response of concrete gravity dams, and also the interaction effect is considered in models. The water is taken as a compressible, inviscid fluid and the foundation as rigid. Gravity dams are considered as 2D structures due to long dimension in cross-stream direction and plane strain assumptions. ANSYS software was used for analysis so that the fixed smeared crack model is used to consider the nonlinear behavior of mass concrete. A flexible layer which is attached to the upstream face of the dam under different thickness and material properties is considered. The response of unisolated and isolated dams is compared under various conditions. Finally, the effect of unisolated and isolated layers in the reduction of the seismic response of the concrete is evaluated under various thicknesses comparatively. Considering obtained results revealed that the layer can have the reducing effect on responses and crack propagation process of dam model because of damping the induced hydrodynamic pressure due to the earthquake.

Anti‐Dam Protests in India: Examining the Profile of the Sardar Sarovar Dam

AbstractAlmost all protests against large dams in India have failed to stop the construction of the respective projects. The latest one is protest against the Sardar Sarovar Dam. Ignoring the demands of the protestors, the height of the Sardar Sarovar Dam has been increased, and in 2017, finally, the 138.68 m high dam was inaugurated by the Indian Prime Minister, Narendra Modi. The construction of the Sardar Sarovar Dam has caused submergence of a large area of land and has displaced many people in the Narmada basin. Due to the impact on local communities, the Narmada Bachao Andolan has been leading peaceful protest against the Sardar Sarovar Dam since the 1980s. In addition to the debates on construction of the Sardar Sarovar Dam is the issue of resettlement and rehabilitation of the people and families affected by it. Protestors and activists allege that the people and families affected have not been properly compensated, resettled, and rehabilitated by the government. This paper critically examines the evolution of the Sardar Sarovar Dam, the impact it has on the people and land in its command area, and the history of protest and activism relating to the dam.

Estimating Reservoir Sedimentation at Large Dams in India

Mathematical expressions are developed that relate the storage capacity loss of reservoirs in India to the catchment area, the reservoir surface area, the original storage volume, and the time since the first filling of the impoundment. The relations for sedimentation of reservoirs found on eastward and westward flowing rivers differ significantly, because of meteorological and geological influences on land surface runoff and sediment yield within reservoir catchments. The formulations give good fits to the assembled data and allow an uncomplicated calculation of the half-life of reservoirs (that is, the time needed for the storage capacity to be reduced by 50%), which offers a measure of when sedimentation will have a significant adverse impact on the functioning of dams.

Review on IoT Based Dam Parameters Monitoring Syste

Dam plays a major role in our life as they are used for purpose such as irrigation flood control and mainly generation of electricity. There are approximately 4200 major/minor dams in India. When it comes to monitoring the parameters of dam such as Water Level, Gate Position, Water Discharge and Seepage tank level the manual method fails. This project will help out to automatically measure as well as display the data parameters. The sensors connected to Raspberry pi 3 measures the parameters and shares the data through IoT to Website. The development of this project not only help to dam authority and disaster management to control the parameters as well as common people to know.

Variability of the useful life of reservoirs in tropical locations: A case study from the Burdekin Falls Dam, Australia

Large dam construction for irrigation, hydropower, water supply, and flood control in tropical to sub-tropical areas increased markedly after 1950. Many of the dams built during this period have filled with sediment and no longer perform to their original design specifications; in many cases, forecast dam life was greatly overestimated. This study investigates the useful life of Burdekin Falls Dam (BFD), northeastern Australia and compares the findings with other tropical reservoirs. Using two independent methods it is estimated that between 61 and 65 million m3 of sediment has been deposited in the reservoir over the 24 years of operation through 2011. This sediment volume equates to an average of 0.15% of capacity lost per year since construction was completed. If current sediment loads/climate regimes persist, reservoir capacity will be reduced by 50% after 345 years. However, the useful life of the BFD reduces to just 276 years when drawdown data are considered; these data show reservoir use would be affected once 40% of storage was filled with sediment, with a 60% drawdown return period of 1 in 15 years. When compared to similar large tropical to sub-tropical reservoirs, the BFD has a slightly longer reservoir useful life than dams in India and a much longer half-life than for both similar-sized and larger dams in China, Brazil, and Iran. Properties of the BFD that promote a longer useful life include a lower trap efficiency, relatively low annual sediment load delivered to the reservoir, limited sediment deposition behind the dam wall (and uniform distribution of deposited sediment), and the export of highly turbid annual floodwaters before settling and deposition of any remaining sediment within the reservoir.

Gender and land dispossession: a comparative analysis

This paper seeks to advance our understanding of the gendered implications of land dispossession. It does so through a comparative analysis of five cases of rural land dispossession driven by different economic purposes in diverse agrarian contexts: the English enclosures; colonial and post-colonial rice irrigation projects in The Gambia; large dams in India; oil palm cultivation in Indonesia; and special economic zones in India. The paper first identifies some of the very common gendered effects of dispossession. In each case, it shows that land dispossession reproduced women’s lack of independent land rights or reversed them where they existed, intensified household reproductive work and occurred without meaningful consultation with – much less decision-making by – rural women. The paper secondly demonstrates ways in which the gendered consequences of land dispossession vary across forms of dispossession and agrarian milieux. The most important dimension of this variation is the effect of land loss on the gender division of labour, which is often deleterious but varies qualitatively across the cases examined. The paper also illustrates important variation within dispossessed populations as gender intersects with class, caste and other inequalities. The paper concludes that land dispossession consistently contributes to gender inequality, albeit in socially and historically specific ways. So while defensive struggles against land dispossession will not in themselves transform patriarchal social relations, they may be a pre-condition for more offensive struggles for gender equality.

Incorporation of “Risk Factor” in Design Flood Review of Existing Dams

At present there are about 4877 completed large dams in India. More than 75% of Indian dams are at least two decades old and for these dams the original design floods call for revisions. Examination of revised design flood studies carried out for a set of 118 dams under ‘Dam Rehabilitation and Improvement Project (DRIP)’ reveal that the design flood values have increased substantially with trends indicating that percentage increases in the revised design flood values are greater for lower dams and also for older dams. Paper illustrates that the upward revision in the design flood estimate of existing dam in no way leads to amplification of the actual risk associated with that dam, and it only underlines the gap between the acceptable risk level and existing risk level. The paper shows that flood related risk mitigation of existing dams is a challenging task often facing constraints of technical and economical viabilities. With the substantial data set of design flood revisions of DRIP dams, the paper brings out the skew observed in distribution of revised design floods on account of present-day norms related to computation of design floods, as contained in the Indian Standard IS: 11223 – 1985 (reaffirmed 1995). Paper also proposes amendments in this Standard in respect of existing large dams with an alternative recourse of formulating a new Standard for revision of design floods incorporating the risk factor associated with these large dam structures.

Integrated Sediment Management in Rivers and Reservoirs

Dam instability and loss of storage capacity are just a few of many problems caused by reservoir sedimentation. With over 5000 large dams in India the impact of reservoir sedimentation is significant and therefore sediment management is of crucial importance. Where the majority of the dams have been clogged up during the past decades, the active removal of sediment from these reservoirs by dredging is necessary to regain its capacity. Sediment removal by dredging is a costly process. However, these costs can be reduced by implementing an innovative circular sediment management plan. By re-using the dredged sediments instead of disposing it as a waste product additional revenue could be generated. A consortium of Dutch companies are preparing a full-scale pilot project to implement the circular sediment management plan for reservoir dredging in India. This paper gives a brief overview of the projected pilot including a circular sediment management plan and a technical approach of the proposed dredging method.

Evaluation of Rubber Dams for SHP in India

India is blessed with great Himalayas as well as hilly areas in peninsular and central areas providing opportunity for hydro power at all scale including Small Hydropower (SHP) development. Water is diverted from the streams for hydro power generation using suitable diversion structures. Conventional types of raised-crest weirs are not well suited for hill streams having steep slopes and boulder movement during floods. Inflatable dam or also known as rubber dam is one type of diversion structure to control and regulate the water for power generation.The experience of inflatable dams in India is very limited even though worldwide over 4,000 installations exist and more than 10 manufacturers offer this type of weir. There are only three installations so far used for irrigation or municipal purposes and not a single rubber dam for hydropower projects in India. For selecting a suitable diversion structure, economic and technical aspects are to be carefully considered. Different types of diversion weirs including rubber dam used for diverting water for Small Hydropower (SHP) projects are studied and presented. The design of diversion weir depends on the quantity of water withdrawal and width of stream. This study is an attempt to study the rubber dam technology for Small Hydropower in India. Five different sites were selected for the present study. Rubber dam was also compared with conventional raised gravity weir, trench weir (Tyrolean), bush and boulder weir and “mathu bund” (a local name). The life cycle of these different types of weirs for same hydraulic conditions and for different discharge were computed and compared with that of imported rubber dam as well as Indian rubber dam. The cost of rubber dam was estimated based on personal communications with the experts of manufacturers and practitioners of the subject area, as well as case studies of already constructed rubber dams in India installed for purposes other than hydropower. Operation and maintenance cost and different losses on account of head, water loss and repair were taken into account for different types of weirs for calculating life cycle cost. Possible damage that may be caused by major flood for different types of weir was also calculated monetarily in terms of power loss. The ease of inflation and deflation reduces the flood damage cost, O & M cost, sediment removal cost and repair work cost. With the comparative analysis, it is found that average life cycle cost of raised gravity weir, bush and boulder, mathu bund and trench weir (Tyrolean), is 2,3, 5 and 6 times respectively more than imported rubber dam. Life cycle cost of Indian rubber dam and average life cycle cost of imported rubber dam is about three times more than Indian rubber dam. It is recommended to use inflated weir in Small Hydropower projects being cost effective and energy efficient.

Thermo-structural monitoring of RCC dam in India through instrumentation

The knowledge of the behavior of any roller compacted concrete (RCC) dam and its foundation is gained by studying the service action of the dam and its foundation using measurements of an external and internal nature. The information by which a continuing assurance of structural safety of the RCC dam can be gauged is of primary importance. Similarly, the fact that the information on structural and thermal behavior and the properties of concrete that may be used to give added criteria for use in the design of future RCC dams is of secondary importance. Wide spread attention is now being given to the installation of more expensive instrumentation for studying the behavior of concrete dams and reservoirs and forecasting of any adverse trends. In view of this, the paper traces installation and need of the comprehensive instrumentation scheme implemented to monitor the structural and thermal behavior of 102.4 m high RCC dam constructed near Mumbai in India. An attempt is made in the present paper to emphasize the need to undertake an instrumentation program and evaluate their performance during construction and post construction stage of RCC structures. Few typical results, regarding the thermal and structural behavior of the dam, obtained through instrumentation installed at the dam site are presented and compared with the design considerations. The fair agreement is seen in the response observed through instrumentation with that governing the design criteria.

Developments to Improve Hydraulic Competence of Spillways

Dams whose collapse could cause loss of life or huge assets damage are considered to survive a probable maximum flood (PMF), but the PMF in various locations has been amplified at regular intervals, resulting in spillways that no longer convene the proposed norms. Spillway rehabilitation is required for lots of dams in India; in order to get better hydraulic competence. Catastrophe in Uttarakhand (June 2013) necessitates the research aspect of spillway rehabilitation. Increasing specific flow form hydraulic structures is one of the thought of spillway rehabilitation. Labyrinth weir may be used for amplifying specific flows of existing spillway. Sediment trapping behind Labyrinth weir might be one of the disadvantages for river with high sediment flow. The Piano Key Weir (PKW), ramped type Labyrinth weir is a hydraulically attractive alternative to linear overflow weirs, increasing the unit discharge for similar heads and spillway widths. This advantage allows operating dam reservoirs on an increased level and provides thereby an enhanced retention volume. It is a result of the non-linear nature of PKW being folded back and forth to make repeated cycles or keys. This type of weir is particularly suitable for sites where topographic conditions limit the extent of its width. Together with its high discharge capacity for low heads, this geometry makes these weirs interesting in spillway rehabilitation. This paper investigates the recent developments to improve hydraulic competence of spillways. Head reduction over crest can improve efficiency as well as reduce submergence. This study shows that for increasing discharge, head reduction with respect to conventional rectangular weir is reducing but reduction was found above seventy percent for all the experiments

Damage–Rupture Process of Concrete Dams Under Strong Earthquakes

A new concept for establishing the damage model for high concrete dams under earthquakes based on damage mechanics is presented in this paper. Unlike the conventional approach of considering the residual deformation by means of plastic-damage coupling, the proposed approach relates the degraded apparent elastic moduli of loading and unloading directly to the material experimental data. As such, the nonlinear analysis of the seismic response of dam-foundation systems is simplified and more reasonable, with no recourse to plastic-damage coupling. To verify the proposed approach of damage–rupture process for high concrete dams, the seismic behaviors of the Koyna gravity dam in India and the Shapai RCC arch dam in China both subjected to strong earthquakes were examined. It is demonstrated that the proposed approach can be reliably used to study the damage–rupture behavior of concrete dams under strong earthquakes.

Problems in Human Rights and Large Dams

This was intended to be included in Anton & Shelton, Environmental Problems and Human Rights (Cambridge, 2011), but space limitations forced its omission from the printed text. Among large infrastructure projects, damming rivers to provide hydroelectric power have been the source of considerable conflict between governments and the people who are affected by such projects, especially those forced to relocate. In many instances dams are built in pristine natural areas, destroying or degrading nature reserves, indigenous lands and/or archaeological sites. Increasing opposition to large dams has resulted in national and international litigation, as well as substantial changes in the practices of international financial institutions. This case study looks at the case of the Narmada dam in India, as it has evolved over time in response to public action, national litigation, and challenges to World Bank financing. In reading these materials, consider the following issues: (1) In developing countries, do the benefits of flood control and the provision of renewable energy outweigh the environmental and human rights impacts of large dams? (2) Can equal or greater benefits be achieved by alternative development projects that have fewer negative impacts on the environment and human rights? (3) By what procedures and substantive measures can the negative impacts be avoided or mitigated? (4) Even if there are considerable benefits to hydroelectric projects, should certain locations be off-limits to the construction of large dams? If so, what are the relevant criteria by which to decide? (5) How should the rights of local communities and indigenous populations be safeguarded?

Development for whom and at whose Cost: Displacement Due to Dams in India

Development for whom and at whose Cost: Displacement Due to Dams in India