Large Hydroelectric Dams Research Articles

Vanishing Nubia

As the Nasserist state built a large hydroelectric dam in the south of Egypt in the early 1960s, Egyptian botanists undertook salvage surveys of the area to be flooded behind the dam, known as historic Nubia. Scientists in these surveys searched for a type of palm tree (Medemia argun) well documented in ancient Egyptian tombs but unrecorded “in living condition” since the late eighteenth century. Gathering written and photographic accounts in memoirs, archives, and botanical tracts, this essay charts the documentary traces of the search for Medemia argun and the affective responses that surface along the margins of texts to show how debate over the potential absence or extinction of a “flagship” endogenous plant coincided with two important shifts in botanical knowledge production: transitions in botany as a discipline that employed new research methodologies and located Egypt “geobotanically” as the temporal and spatial origin for world flora; and transitions in botany as an arena of scientific expertise during postcolonial nationalism's reordering of the Egyptian academy. Building on extinction and destroyed landscape studies, this article explores ecological lexicons of absence and practices of “following” in botany.

Functional responses of amazonian frogs to flooding by a large hydroelectric dam

Functional responses of amazonian frogs to flooding by a large hydroelectric dam

Anthropogenic Changes in Land Use Impact the Emergence and Transmission of Infectious Diseases

Human interventions in natural landscapes have promoted rapid and profound transformations in the environment, generating great impacts at different levels, including on human and animal health. Actions such as deforestation for logging, intensive agriculture, construction of large hydroelectric dams, pastures for cattle, mining, and construction of roads that favor human access to remote areas have promoted habitat destruction, changes in trophic chains due to nutritional factors, loss of biodiversity, changes in the natural balance of vectors, mammals, hosts and pathogen reservoirs, and closer human contact with wildlife. Another important impact related to changes in land use is forest and habitat fragmentation. According to different investigations, anthropogenic actions causing changes in land use are potential inducers of emergence/reemergence and increased transmission of infectious diseases in the world, including those with pandemic potential. Most of these diseases are classified as zoonoses and many are arboviruses. Deforestation and agricultural intensification seem to be the events that most influence the incidence of zoonoses. Changes in land use may also favor a species jump to a zoonotic pathogen, making it a potential threat to humanity if it acquires an efficient capacity for inter-human transmission. Here, we summarize important evidence on how anthropogenic changes in land use influence the emergence and transmission of infectious diseases to humans.

Biogeographic patterns of meio- and micro-eukaryotic communities in dam-induced river-reservoir systems.

Although the Three Gorges Dam (TGD) is the world's largest hydroelectric dam, little is known about the spatial-temporal patterns and community assembly mechanisms of meio- and micro-eukaryotes and its two subtaxa (zooplankton and zoobenthos). This knowledge gap is particularly evident across various habitats and during different water-level periods, primarily arising from the annual regular dam regulation. To address this inquiry, we employed mitochondrial cytochrome c oxidase I (COI) gene-based environmental DNA (eDNA) metabarcoding technology to systematically analyze the biogeographic pattern of the three communities within the Three Gorges Reservoir (TGR). Our findings reveal distinct spatiotemporal characteristics and complementary patterns in the distribution of meio- and micro-eukaryotes. The three communities showed similar biogeographic patterns and assembly processes. Notably, the diversity of these three taxa gradually decreased along the river. Their communities were less shaped by stochastic processes, which gradually decreased along the longitudinal riverine-transition-lacustrine gradient. Hence, deterministic factors, such as seasonality, environmental, and spatial variables, along with species interactions, likely play a pivotal role in shaping these communities. Environmental factors primarily drive seasonal variations in these communities, while hydrological conditions, represented as spatial distance, predominantly influence spatial variations. These three communities followed the distance-decay pattern. In winter, compared to summer, both the decay and species interrelationships are more pronounced. Taken together, this study offers fresh insights into the composition and diversity patterns of meio- and micro-eukaryotes at the spatial-temporal level. It also uncovers the mechanisms behind community assembly in various environmental niches within the dam-induced river-reservoir systems. KEY POINTS: • Distribution and diversity of meio- and micro-eukaryotes exhibit distinct spatiotemporal patterns in the TGR. • Contribution of stochastic processes in community assembly gradually decreases along the river. • Deterministic factors and species interactions shape meio- and micro-eukaryotic community.

The impact of Three Gorges Dam on the hydrological connectivity of “off-stream” floodplains

The construction of dams has led to concerns about ecological deterioration due to the weakening of hydrological connectivity. However, existing assessments of hydrological connectivity have focused on the damming effect on upstream–downstream connectivity, neglecting the impact on “off-stream” floodplains and resulting in an underestimation of dam’s overall impact. This study took the Three Gorges Dam (TGD), the world’s largest hydroelectric dam, as an example to assess its impact on the hydrological connectivity of the Yangtze-connected floodplain, Poyang Lake, through hydrodynamic modeling. The results revealled significant alterations caused by the dam construction, particularly during the receding period. The connectivity function (CF), representing the ability of water movement in different directions, was found to decrease due to the TGD. The average reduction in the North-South CF was 17.38 %, while the West-East CF decreased by an average of 13.62 %. Moreover, the dam’s most pronounced impact was observed during specific periods. The average shrinkage of the connected object (CONNOB) was 55.17 % during drought years, 83.25 % during normal years, and 64.61 % during flood years. Additionally, these CONNOBs exhibited fragmentation, indicating a disrupted hydrological network. Furthermore, the dam-induced changes affected the timing of the longest connected period in the seasonal isolated lake. On average, during normal years, this period began 69.41 days earlier and ended 70.36 days earlier. The intensification of autumn drought caused by the emptying effect of the TGD is the underlying mechanism of the weakened hydrological connectivity in Poyang Lake. This study provides new insights into assessing the impact of dams on hydrological connectivity and can improve the current assessment framework, leading to better ecological and environmental benefits of water management related to hydrological connectivity adjustment.

Itaipu Binational Dam: A Quantitative Analysis of the Economic and Social Impacts in Paraguay. Successful or not?

The Itaipu Binational dam is a giant hydroelectric project situated on the Parana River, which began its construction in 1973 and was completed in 1983. It was undertaken by Brazil and Paraguay, two countries with enormous geopolitical and economic differences. With 14,000 MWh of installed power, it is the second largest hydroelectric dam in the world. Both countries are partners in this project, but the socioeconomic results have not been as expected. In this regard, although Paraguay’s GDP per capita, between 1983 and 2020, increased by 341%, Itaipu did not represent a true economic development engine for Paraguay. On the other hand, it had serious negative impacts especially on social, demographic, and environmental aspects. A structural equations model (SEM) was designed, in its Path Analysis modality, which includes 10 variables: 3 exogenous (Royalties from Itaipu, Electric power exports, and External debt) and 7 endogenous (GDP per capita, Proportion of agricultural sector in GDP, Proportion of service sector in GDP, Population with needs unsatisfied, Housing deficit, Changes of land use, and CO2 emissions). The model exposes an adequate simulation range, and the results show a high degree of goodness of fit, using different indices (CMIN, FMIN, CFI, and RMSEA). The corresponding tests upon the model validate the hypotheses raised. JEL Classification: O13, O54, H54, H60, F34, C18

Elements and omega-3 fatty acids in fishes along a large, dammed river

Damming of a river can trap and elevate levels of sediment-bound elements and alter food web dynamics in created reservoirs. It follows that dams may alter how elements and other nutrients, like the beneficial omega-3 fatty acids (n-3 FAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are accumulated in fish and thus the chemical composition of species above and below this barrier to migration. This study examined the spatial and species differences in contaminants and nutrients in fish from the Wolastoq | Saint John River (New Brunswick, Canada) in association with a large hydroelectric dam (Mactaquac Generating Station; MQGS), a river which supports both recreational fisheries and subsistence fishing by Indigenous communities. In 2020 and 2021, Smallmouth Bass, Yellow Perch, American Eel, and Striped Bass were collected from locations upstream (reservoir and river) and downstream of the MQGS and analyzed for mercury (Hg) and 30 other trace elements, n-3 FAs, δ15N, and δ13C. Fish from the reservoir were highest in the beneficial elements P, S, and K, while fish from upstream of the reservoir had lower levels of toxic elements, including Hg. The dam appeared to alter food web dynamics, as fish from the reservoir and immediately downstream of the dam had higher δ15N and reservoir fish were depleted in δ13C. DHA and Hg were positively corelated with δ15N, and EPA in Smallmouth Bass was higher in sites where fish had higher δ13C. Overall, this study suggests that the dam altered food web dynamics and the uptake of contaminants and nutrients by fish, and that location and species are important factors when examining the risks and benefits of consuming wild fish from a system impacted by a large dam.

Development of Hydropower and the Environmental Impacts of Hydroelectric Dam Construction in China

The need to mitigate climate change and reduce carbon emissions has resulted in an increasing demand for the transition from fossil fuels to renewable sources of energy. Hydropower, in particular, has emerged as a prominent and extensively developed source of renewable energy in recent decades. This specific renewable energy harnesses the kinetic energy of falling or fast-flowing water to generate electricity. Despite being a dependable, adaptable, and cost-effective energy source, previous studies have highlighted the detrimental ecological effects of hydropower, ranging from altered land use to the disruption of natural habitats in the vicinity of dams. The main purpose of this study is two-fold. First, the change of renewable energy, particularly hydropower, is evaluated from 2000 to 2020 in China and globally, highlighting the leading role of hydropower in renewable energy generation. Second, this study aims to investigate the environmental influences of large hydroelectric dam construction and perform a case study of the Three Gorges Dam in China. The Pearson's linear correlation analysis was utilized to identify the association between hydropower and climate, and biodiversity, individually. Although dam construction can boost hydroelectricity generation, it can also have adverse effects on the regional climate and result in substantial depletion of biodiversity. This study will shed light on potentially reliable strategies to optimize the advantages of hydropower and minimize the negative environmental impacts of large-scale dam construction.

An ethic of co-inhabitation for the biocultural conservation of rivers

During the 20th century, numerous rivers were pumped, channeled, stratified, dammed, and diverted. Diverse water courses and bodies (rivers, streams, lakes, wetlands, estuaries, and aquifers) were transformed for agricultural irrigation and energy purposes, supplying urban areas or simply favoring economic interests. These transformations were driven by a mentality inherited from modernity that has led to understanding and exploiting rivers as mere water channels or fuel for hydroelectric power plants. This one-dimensional mentality continues to promote the conversion of rivers into paved channels and/or their clogging by constructing large hydroelectric dams worldwide. In this article, I use the conceptual framework of the “3Hs” (Habits, Habitats, co-in-Habitants) of my biocultural ethics to criticize the problematic modern habit of indiscriminately channeling water courses, which leads to the proliferation of homogeneous habitats (crossed by captive water courses) that entail the suffering or elimination of myriads of co-inhabitants. These co-inhabitants include both the exuberant biological diversity that inhabits rivers (freshwater fish, insects, plants, algae, and bacteria) and the rich cultural diversity of human communities that co-inhabit watersheds. In addition, the “3Hs” model of my biocultural ethics can guide us to protect and/or regenerate connections between human societies and rivers, transforming not only biophysical habitats but also our symbolic and material culture. I explore how the perspective of my biocultural ethics supports and is supported by: (i) the philosophical revaluation of the concept of meander developed by environmental thinker Irene Klaver; (ii) innovative scientific methodologies to study river biota proposed by freshwater ecologist Tamara Contador; (iii) the recent legal attribution of biocultural rights to rivers in Colombia, New Zealand, and India; and (iv) expressions of indigenous poets and other artists that communicate deep river-human interconnections. On the one hand, adopting my proposed biocultural ethics requires us to abandon a one-dimensional mentality to embrace ancient and new forms of systemic, contextual, complex, and dynamic thinking to understand and value rivers. On the other, we must cultivate habits of care for riparian habitats where we co-inhabit with various co-inhabitants (humans and other-than-humans), seeking their well-being. Thus, an ethic of co-inhabitation emerges that guides us to value and defend the biocultural conservation of rivers.

Death by a thousand cuts: Small local dams can produce large regional impacts in the Brazilian Legal Amazon

In the Amazon Basin, large-scale problems, such as deforestation, over-fishing, climate change and large hydroelectric dams, are now recognized. However, many small-scale activities could exert significant cumulative, negative environmental impacts. We conducted a spatial analysis of small-scale dams used for hydropower and aquaculture in the central and southwestern portions of the Brazilian Amazon Basin. We found a very high density of small dams in these areas, and suggest that these dams, in the aggregate, are in fact pernicious because they are likely to have large impacts on the aquatic environment of these sub-basins in the Amazon. We recommend increasing the size and number of protected areas where dams are not allowed, and restricting the number of licenses for dams in order to reduce future intensification of their impacts.

Ecological connectivity of the upper Rhône River: Upstream fish passage at two successive large hydroelectric dams for partially migratory species

The restoration of migration pathways for fish is crucial for the maintenance of populations in a worldwide context of increasing river fragmentation due to the development of dams. Studies aiming at quantifying fish passage at dams through fishway efficiency estimates concern few species, mostly diadromous. Data are lacking regarding most potamodromous species, despite their need to move to complete their life cycles. This study aimed to evaluate the efficiency of two vertical slot fishways for upstream fish migration on two consecutive run-of-the-river hydropower dams (Verbois and Chancy-Pougny) on the Rhône River. Radiotelemetry and PIT-tagging were used together (1) to describe the behaviour of fish under the dams and (2) to quantify entrance probability and passage efficiency of the fishways, for three potamodromous, partially migratory species, comprising of two cyprinids (Barbus barbus and Squalius cephalus) and one salmonid (Salmo trutta). The study revealed that fish preferentially moved upstream of the dam beside the gates, independently of their opening, rather than in the main flow of the turbines. While the passability of fishways did not differ among species (68% for all species), the attractiveness was dependent on the dam/fishway, the species and some individual characteristics such as fish body length and condition. A few fish remained below the gates or near the fishway for a long time, up to several months, without being able to detect the entrance. Overall, results revealed a lower efficiency of the fishways for trout than for the two cyprinids. Attraction was pointed out as the major limiting factor to the efficiency of the Verbois fishway for barbel and trout. Overall, results suggested to better account for fish motivation (migratory behaviour) to assess fishway efficiency for these species.

Impactos da UHE de Belo Monte para os pescadores artesanais da Colônia Z-57, em Altamira, PA, Brasil.

The trauma that resulted from the construction of large hydroelectric dams in the Amazon is marked by major social and environmental restructuring, plunder, and impacts, on Indigenous Lands, Conservation Units, and residents on the outskirts of cities or through the country roads. In general, the effects caused by the Belo Monte HPP gain prominence and production, in which one of them composes the objective of this article: to analyze the impacts on the fishing territory. Having as methodological path the bibliographic review, field, and relative work with the fishermen of the Fishing Colony Z-57. It appears that the installation of the plant ended up deleteriously altering the systemic and cultural relations, under which the fishing territory is expressed. Compromising it, translating into low fishing stocks in the communities; a decrease of up to 70% in fisheries production and, consequently, an increase in pain and economic costs for carrying out the activity. It was evident that the legal frameworks and the licensing instruments, all the judicialization resulting from these infrastructure projects, and the struggle imposed on their installation, were not capable of safeguarding the interests of society - fishermen, specifically - in the face of the despoliation effect of the construction of the hydroelectric dam on the fishing territory.

Impacts of a large hydroelectric dam on the Madeira River (Brazil) on floodplain avifauna

ABSTRACT Hydroelectric dams represent an important threat to seasonally flooded environments in the Amazon basin. We aimed to evaluate how a dam in the Madeira River, one of the largest tributaries of the Amazonas River, affected floodplain avifauna. Bird occurrence was recorded through simultaneous passive acoustic monitoring in early successional vegetation and floodplain forest downstream from the dam and upstream in sites impacted by permanent flooding after dam reservoir filling. Species were identified through manual inspection and semi-automated classification of the recordings. To assess the similarity in vegetation between downstream and upstream sites, we used Landsat TM/ETM+ composite images from before (2009-2011) and after (2016-2018) reservoir filling. Downstream and upstream floodplain forest sites were similar before, but not after dam construction. Early successional vegetation sites were already different before dam construction. We recorded 195 bird species. While species richness did not differ between upstream and downstream sites, species composition differed significantly. Ten species were indicators of early successional vegetation upstream, and four downstream. Ten species were indicators of floodplain forest upstream, and 31 downstream. Seven of 24 floodplain specialist species were detected by the semi-automated classification only upstream. While we found some bird species characteristic of early successional vegetation in the upstream sites, we did not find most species characteristic of tall floodplain forest. Predominantly carnivorous, insectivorous, and nectarivorous species appear to have been replaced by generalist and widely distributed species.

Whither Wintego: Environmental Impact Assessment and Indigenous Opposition in Saskatchewan’s Churchill River Hydropower Project in the 1970s

This article details Saskatchewan’s first environmental impact assessment, which took place in the 1970s over a proposed dam on the Churchill River at the Wintego Rapids. The Wintego Dam, which would have been the largest hydroelectric dam in the province at the time, was controversial because of the environmental repercussions and impacts on the local Indigenous communities, particularly the Peter Ballantyne Cree Nation. We show that the Blakeney ndp government did not initially intend to create a robust environmental impact assessment, and then explain how and why such an assessment was ultimately undertaken. Using archival material that was previously unavailable, the article recounts the governmental study, the Indigenous-led studies (after they rejected the governmental process), and the final Board of Inquiry report. The Wintego saga should be understood within the context of a growing resistance to northern development projects whose benefits accrued mostly to the southern white population. Ultimately, the Blakeney government decided not to build Wintego because of the economic, environmental, and social impacts, as well as concerns about unsettled treaty claims. This could be considered the first attempt – even before the Berger Inquiry – by a provincial government to fully assess the impacts of a natural resource project before final approval, and it was the earliest incorporation of Indigenous-led studies into the assessment process.

Are large-scale hydroelectric dams inherently undemocratic?

Construction of large-scale hydroelectric dams has increased in recent decades in the Global South and emerging economies. Population resettlement is one of the most severe socioeconomic impacts caused by dam construction. Processes aiming to mitigate its impacts and restore livelihoods are often described as inadequate. The resettlement process’ ineffectiveness could be explained by persistent deficiency in citizen participation, which is also a sign of the impacted population not being able to participate in the process affecting their lives. Our research presents a medium-N comparative study showing the pathways explaining deficiency of participation across 23 large-scale hydroelectric dams in Asia, Africa, and Latin America. We conducted a fuzzy-set Qualitative Comparative Analysis based on information from a qualitative meta-analysis and secondary sources. Our results suggest that there are at least two scenarios to explain deficiency in participation. The first scenario includes dams constructed during autocracies, mostly before the release of the World Commission on Dams guidelines. The second scenario involves the largest dams in our analysis, with high economic and political interests at stake built under both autocratic and democratic regimes, despite the presence of what we categorized as effective forms of public opposition to the project and resettlement process. We discuss features that make large hydroelectric dams less participatory or inherently undemocratic in the Global South.

Ghana's Akosombo Dam, Volta Lake Fisheries & Climate Change

Abstract In Ghana, the Pwalugu Dam in the Upper East is in the final planning stage. Whereas promoters of Ghana's first dams emphasized the need for generating electricity to modernize and industrialize the new nation, the planners of Pwalugu have focused on water issues. Due to climate change, droughts have had a devastating impact on local agriculture. The dam's primary purpose is an irrigation scheme and flood control. This essay historicizes these concerns by revisiting the Akosombo Dam, Ghana's largest hydroelectric dam, completed in 1965. The discussion juxtaposes personal recollections of dam-affected communities with reports by administrators, biologists, and social scientists. The essay draws on government records, scientific studies about Volta Lake, and oral histories. Ultimately, it argues, builders and administrators of the Akosombo Dam failed to address most water issues, despite ample knowledge about their existence. One hopes that these shortcomings will not be repeated in the Pwalugu project.

Impacts of an Amazonian hydroelectric dam on frog assemblages.

About 90% of the Amazon’s energy potential remains unexploited, with many large hydroelectric dams yet to be built, so it is important to understand how terrestrial vertebrates are affected by reservoir formation and habitat loss. We investigated the influence of the construction of the Santo Antônio Hydroelectric dam on the Madeira River in southwestern Amazonia on the structure of frog assemblages based on samples collected in two years before the dam flooded (pre-stage) and one (post1-stage) and four years (post2-stage) after its construction. We surveyed five 500-ha plot systems three times during each stage; in the pre-stage we sampled 19 plots in low-lying areas that would be flooded by the dam, (from now called flooded pre-stage plots) and 45 plots in terra-firme forest (from now called unflooded pre-stage plots). At the post1-stage we sampled the 45 unflooded plots and in the post2-stage we sampled the remaining 39 unflooded plots. We detected frogs by active visual and acoustic searches standardized by both time and sampling area. Few species recorded in the pre-stage flooded plots were not found in the pre-stage unflooded plots or in stages after flooding. However, the composition of frog assemblages based on relative densities in flooded pre-stage plots did not re-establish in plots on the new river margins. In unflooded areas, frog assemblages were distinct among the flooding stages with no tendency to return to the original assemblage compositions even four years after the dam was filled. For the areas that were not flooded, there was an increase in species richness in 82% of the plots between the surveys before dam construction and the first surveys after dam completion, and 65% between the pre-stage and surveys four years after dam completion. Lack of understanding by the controlling authorities of the long-term effects of landscape changes, such as water-table rises, means that studies covering appropriate periods post construction are not required in legislation, but the data from Santo Antônio indicate that changes due to dam construction are either long-term or difficult to distinguish from natural fluctuations. Future environmental-impact studies should follow strict BACI designs.

Resumption of Anadromy or Straying? Origins of Sockeye Salmon in the Elwha River

AbstractWhen barriers to migration are removed, anadromous fishes from other rivers may colonize newly accessible habitat or landlocked forms of the species may resume anadromy if conditions allow. For example, two large hydroelectric dams on the Elwha River, Washington, were removed between 2011 and 2014 to restore populations of Pacific salmon Oncorhynchus spp. after a century of isolation. Immediately prior to and following dam removal (2010–2017), upstream‐migrating adult Sockeye Salmon Oncorhynchus nerka were sampled, and DNA was extracted and compared with samples from the local Lake Sutherland population (above the lower dam’s former location) and a coastwide genetic baseline to determine the probable origin of each fish. Genetic analysis indicated that none of the 45 Sockeye Salmon sampled had originated from the local population or other populations nearby in the genetic baseline, and only a single fish originated from the abundant and proximate Fraser River populations. The strays reflected two different sources and processes: 22 were from the west coast of Vancouver Island (all in 2015, when these populations were very abundant and encountered conditions unfavorable for upstream migration in their natal system) and another 22 assigned to more northerly populations, mostly to riverine populations from the Stikine River. Test fishery samples collected in the Strait of Juan de Fuca contained very few fish with assignments similar to these northern rivers. It is not clear whether these individuals originated from the distant riverine populations or from a closer population not in the baseline that resembles them genetically. Taken together, the findings indicate that the genetic composition of any future population in the Elwha River may reflect signatures from diverse sources and subsequent selection in the new habitat.

Human Rights and Corporate Reinsurance: From Ensuring Rights to Insuring Risks

ABSTRACT With the aim of grounding the analysis of private transnational human rights governance, the article examines how a European reinsurance company links its human rights policy to its core business of underwriting risks in the case of Belo Monte, a large hydroelectric dam in the Brazilian Amazon. Based on the current international regulatory framework, the global political economy of reinsurance is becoming a constitutive element of human rights governance. Conceptualising underwriting as a social practice, we observe how human rights norms are translated into the corporate form of risks. This process goes beyond questions of norm compliance and involves practices of valuation and boundary-drawing based on the underwriter’s competences and background knowledge about reinsurance markets, value chains and corporate hierarchies. We conclude with a critique of private governance as an institutional pillar of the human rights system that rests on business rationales rather than lending institutional power to rights-holders.

Environmental Change, Water Scarcity and Farmers' Differentiated Adaptations: Evidence from the Three Gorges Dam

Using the 2003 initial impoundment of the world's largest hydroelectric dam as a natural experiment, we assess how rural households with varying endowments adapt differently to the dam-induced water scarcity in the downstream area. In response to a 13\% reduction in rice yields, those who are wealthier and more experienced in market transaction, and less constrained by access to credit, made up their income loss from agriculture by allocating 4.5-6 times more labor days (equivalent to 97 to 106 days per year) to non-agricultural activities, whereas the disadvantaged ones expanded the acreage of rice cultivation. These differential strategies adopted by these households resulted in widening income inequality.