Large Dams Research Articles

Persistent disconnect between flow restoration and restoration of river ecosystem functions after the removal of a large dam on the Sélune River

The removal of the two dams on the Sélune River since 2019 has led to profound changes in the aquatic ecosystem. Lentic habitats bordered by forest had shifted to new conditions (running water and sparsely vegetated riverbanks) therefore shaping organisms’ assemblies. We studied how the reestablishment of aquatic lotic habitats in interaction with riparian vegetation could mediate the restoration of important ecological functions in the new river. Six stations located along the river continuum were surveyed for 3 years after dam removal: two control stations upstream the former reservoir, three restored stations within the former reservoir, and one control station downstream. We monitored physico-chemical characteristics, phytobenthos biomass and the river’s benthic metabolism, and assessed the functional composition of macroinvertebrate communities. We compared the recorded variables among upstream, downstream and restored sampling stations. We observed a rapid recolonization by invertebrates, but a still low phytobenthic primary production in restored stations. Such a low primary productivity was also reflected in the functional composition of invertebrate communities. Three years after dam removal, there was still a significant time lag between communities recovery and expected ecosystem functioning restoration. We observed a quick colonization by aquatic running-water invertebrate communities of new lotic reaches, but a slower recovery of important ecological functions rates such as those observed in control stations.

Vegetation responses to large dam removal on the Elwha River, Washington, USA

Large dam removal can trigger changes to physical and biological processes that influence vegetation dynamics in former reservoirs, along river corridors downstream of former dams, and at a river’s terminus in deltas and estuaries. We present the first comprehensive review of vegetation response to major fluvial disturbance caused by the world’s largest dam removal. After being in place for nearly a century, two large dams were removed along the Elwha River, Washington, USA, between 2011 and 2014. The exposure, erosion, transport, and deposition of large volumes of sediment and large wood that were impounded behind the dams created new fluvial surfaces where plant colonization and growth have occurred. In the former reservoirs, dam removal exposed ~290 ha of unvegetated sediment distributed on three main landforms: valley walls, high terraces, and dynamic floodplains. In addition to natural revegetation in the former reservoirs, weed control and seeding and planting of desirable plants influenced vegetation trajectories. In early years following dam removal, ~20.5 Mt of trapped sediment were eroded from the former reservoirs and transported downstream. This sediment pulse, in combination with transport of large wood, led to channel widening, an increase in gravel bars, and floodplain deposition. The primary vegetation responses along the river corridor were a reduction in vegetated area associated with channel widening, plant establishment on new gravel bars, increased hydrochory, and altered plant community composition on gravel bars and floodplains. Plant species diversity increased in some river segments. In the delta, sediment deposition led to the creation of ~26.8 ha of new land surfaces and altered the distribution and dynamics of intertidal water bodies. Vegetation colonized ~16.4 ha of new surfaces: mixed pioneer vegetation colonized supratidal beach, river bars, and river mouth bars, and emergent marsh vegetation colonized intertidal aquatic habitats. In addition to the sediment-dominated processes that have created opportunities for plant colonization and growth, biological processes such as restored hydrochory and anadromous fish passage with associated delivery of marine-derived nutrients may influence vegetation dynamics over time. Rapid changes to landforms and vegetation growth were related to the large sediment pulse in the early years following dam removal, and the rate of change is expected to attenuate as the system adjusts to natural flow and sediment regimes.

Threats of dams to the persistence of the world's freshwater fishes

AbstractHabitat fragmentation due to dams is a well‐known threat to freshwater fish. Yet, the global consequences of fragmentation for the viability of freshwater fish populations are unknown. Here, we provide the first global assessment of the threats of dams to the persistence of freshwater fish species. We developed a global macroecological relationship between freshwater fish range size and body size and used this relationship to assess whether isolated range fragments are too small to support a species. Our assessment includes 7369 freshwater fish species and considers the effects of 31,780 dams globally. Furthermore, we performed a more detailed analysis of the threats of dams in Brazil, the greater Mekong region and the United States, using complementary national and regional data sets. Globally, more than half of the species analysed face extirpation in a part of their geographic range, with an average potential range loss of 3.3% (95%‐range: 0%–31.8%) across all species analysed. For 74 fish species, occurring in Brazil, China, India, the Mekong basin, the United States, South‐Africa and the East Adriatic Coast, more than 50% of their range is potentially lost. This includes 18 species threatened with extinction across their whole range. Our complementary regional analysis revealed that the potentially lost range increases by a factor of 2–4 when considering both large and small dams compared with considering only large dams (≥15 m), highlighting the need to establish more comprehensive global dam inventories. Our novel approach and global analysis identifies species at risk of extirpation as well as geographic hotspots of extirpation threat by dams, which can aid in establishing more effective strategies for global hydropower development and barrier removal efforts to optimise the trade‐offs between biodiversity conservation and the socio‐economic benefits of dams.

Attribution of Moisture Sources for Summer Precipitation in the Upstream Catchment of the Three Gorges Dam

Abstract Currently, there is a lack of investigating moisture sources for precipitation over the upstream catchment of the Three Gorges Dam (UCTGD), the world’s largest dam. Using the dynamical recycling model (DRM), trajectory frequency method (TFM), and the Climate Forecast System Reanalysis (CFSR), this study quantifies moisture sources and transport paths for UCTGD summer precipitation from 1980 to 2009 based on two categories of sources: region-specific and source-direction. Overall, the land and oceanic sources contribute roughly 63% and 37%, respectively, of the moisture to UCTGD summer precipitation. UCTGD and the Indian Ocean are the most important land and oceanic sources, respectively, in which the southern Indian Ocean with over 10% of moisture contribution was overlooked previously. Under the influence of the Asian monsoon and prevailing westerlies, the land contribution decreases to 57.3% in June, then gradually increases to 68.8%. It is found that for drought years with enhanced southwest monsoon, there is a weakening of the moisture contribution from the C-shaped belt along the Arabian Sea, South Asia, and UCTGD, and vice versa. TFM results show three main moisture transport paths and highlight the importance of moisture from the southwest. Comparison analysis indicates that, generally, sink regions are more affected by land evaporation with their locations more interior to the center of the mainland. Furthermore, correlations between moisture contributions and indices of general circulation and sea surface temperature are investigated, suggesting that these indices affect precipitation by influencing moisture contributions of the subregions. All of these are useful for comprehending the causes of summer UCTGD precipitation. Significance Statement Quantitative research on the moisture sources of summer precipitation has been implemented for the upstream catchment of the Three Gorges Dam (UCTGD), which is of particular hydrological significance but has not been investigated previously. The dynamical recycling model (DRM)–trajectory frequency method (TFM) approach is used to quantify and interpret the results of the moisture sources both in different specific subregions and directions, which produce more meaningful results than a single method for the areal division of moisture sources. Furthermore, antecedent indices that significantly influence the following moisture contributions of the subregions and then summer UCTGD precipitation are studied in terms of large-scale general circulation indices, which would help our understanding of precipitation forecast for UCTGD.

Poverty-Food Insecurity Nexus in the Post-Construction Context of a Large Hydropower Dam in the Brazilian Amazon.

Within the 2030 Sustainable Development Agenda, large hydropower dams are positioned as a sustainable energy source, notwithstanding their adverse impacts on societies and ecosystems. This study contributed to ongoing discussions about the persistence of critical social issues, even after the investments of large amounts of resources in areas impacted by the construction of large hydropower dams. Our study focused on food insecurity and evaluated this issue in the city of Altamira in the Brazilian Amazon, which has been profoundly socially and economically impacted by the construction, between 2011 and 2015, of Brazil's second-largest dam, namely, Belo Monte. A survey in Altamira city featured a 500-household random sample. Structural equation modeling showed conditioning factors of 60% of the population experiencing varying food insecurity degrees. Poverty, female-led households, lower education, youth, and unemployment were strongly linked to higher food insecurity. Crowded, officially impacted, and resettled households also faced heightened food insecurity. Our findings underscore the food insecurity conditions in the region impacted by the Belo Monte dam, emphasizing the need to take into account this crucial issue while planning and implementing hydropower dams.

Limits of inter-American cooperation: large dams and urban planning in Latin America after 1945

ABSTRACT Large dams are crucial sites for urban planning because they normally require the construction of relocated settlements, industrial towns, and workers’ camps. After 1945, Latin America emerged as one of the important centres for dam-building. The planning of urban structures built in this context represents a basic tension of inter-American cooperation. Whereas the initial model of such settlements was the U.S. company town and some countries like Venezuela even contracted urban planners from the United States, Latin American countries used urban planning to prove their planning capabilities. Even though they adapted Western lifestyle and housing, they were eager to keep out direct influence from abroad. On the other hand, dam towns were manifestations of the pitfalls of modern urban planning since they produced socially segregated spaces and strengthened social inequality. Engineers and middle-class inhabitants enjoyed a certain comfort, but resettled people and workers often faced difficult living conditions and protested against the urban planning policy.

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.

Quantitative assessment of sedimentation in Moroccan dam reservoirs: analysis and projections

The siltation of dam reservoirs is the phenomenon that most embarrasses dam managers and water reservoir operators. In Morocco, this phenomenon affects all the watersheds to different degrees. Dam managers schedule bathymetric measurement companies to estimate the quantities of mud deposited in reservoirs. These companies are neither regular in time nor generalized on the 152 large dams of the Kingdom because of the high cost of the bathymetry operations. In our research work, the bathymetric data available for about a century were collected, checked, corrected, and sorted to be exploited.In the next step, we extrapolated over time and updated the siltation rates for each dam according to the trend curves of the evolution of silted volume. Most of these trend curves were linear. For the nonlinear curves, we looked for explanations throughout history. These are dams whose reservoirs have undergone human intervention such as desilting operations or emptying of reservoirs, or following natural phenomena such as drought or exceptional floods. The research work subsequently made it possible to estimate the annual siltation rates for 53 large dams whose reservoir capacities total approximately 92% of that of the entire country. It also revealed an overall siltation rate of 18.14% for the entire country and rates ranging from 10% to 52% for each watershed. The discussions of these results in this article give explanations on the highest rates, based on the natural data of the watersheds in question. These results will help decision-makers to define the priorities of desilting operations or the construction of new dams, help investors and industrialists wishing to extract and use mud from dam reservoirs as raw material, and can also be used in various scientific fields such as dam reservoir management, flood risk prevention, environmental impact studies, spatial planning, and research and development studies.

Influence of morphological features on mechanical properties of granular soils from different depositional environments

The behavior of granular soils is intricately linked to their origin and sedimentation mechanisms, as evidenced by their unique morphological characteristics shaped by depositional environments. This study investigates into the critical relationship between these morphological attributes, including sphericity, angularity, and roundness, and the mechanical properties of granular soils. Such understanding is pivotal for applications like piled foundations, large dam filters, and pavements in geotechnical engineering. To assess this relationship, three granular soils from distinct depositional environments were selected, and their morphological features were meticulously examined using scanning electron microscopy (SEM) and analyzed using ImageJ software. Additionally, surface roughness parameters were quantified through an optical profilometer. The mechanical response of these soils was comprehensively investigated through direct shear tests, with a specific focus on the impact of shape factors. The results of this study unveiled striking differences between river sand deposits and coastal sand in terms of morphological attributes. River sand exhibited higher angularity, reduced roundness, and a greater number of surface asperities, contributing to heightened frictional resistance and pronounced dilatancy effects when subjected to shear loads. This paper underscores the significance of morphological features in influencing the macroscale properties of granular soils and provides valuable insights for geotechnical engineering applications.

Salinity management of reservoirs by linking hydrodynamic model, surrogate model, and evolutionary optimization

This study proposes a combined system for salinity management of reservoirs in which the lake ecosystem simulation is integrated with the reservoir operation optimization. A finite volume-based depth-averaged model is applied for simulating salinity in the reservoir for a long-term period. Then, a surrogate model is developed by applying outputs of the fluid dynamic model using adaptive neuro-fuzzy inference system. The surrogate model is used in the structure of the optimization model to estimate the average salinity concentration in the reservoir. Two objectives are defined in the reservoir operation optimization including minimizing water supply loss and mitigating salinity impacts on the aquatic habitats in the lake ecosystem. According to case study results, the fluid dynamic model is reliable for simulating salinity distribution in the reservoir, which means it is recommendable for simulating salinity distribution of reservoirs. Moreover, The Nash–Sutcliff coefficient of surrogate model is 0.79, which implies it is reliable for applying in the optimization model as a surrogate model of salinity. Based on the environmental considerations, 0.55 ppt was defined as the average threshold of habitat suitability. Average optimal salinity during the simulated period is 0.52 ppt, which implies the optimization model is able to reduce salinity impacts properly. We recommend using the proposed method for the case studies in which increasing salinity is an environmental challenge for the aquatic species those living in the artificial lakes of large dams.

Pork carcass composition, meat and belly qualities as influenced by feed efficiency selection in replacement boars from Large White sire and dam lines

This study evaluated carcass attributes, meat and belly qualities in finisher boars (n = 79) selected for feed efficiency (low, intermediate and high) based on estimated breeding value for feed conversion ratio within a Large White dam and sire genetic lines. The sire line had lower trimmed fat proportions and higher lean than the dam line (P < 0.01). Genetic lines expressed slight colour changes and drip losses (P < 0.05), with no differences in pH, marbling and cooking traits (P > 0.05). High-efficient animals presented the highest lean yield (P < 0.01), the lowest trimmed fat proportion (P < 0.01) and no effect on meat and belly quality attributes (P > 0.05) compared with other efficient groups. Interaction between efficiency group and genetic line was only detected for belly weight and thickness (P < 0.01). High-efficient animals offer a greater leanness level, with minimal impact on meat and belly quality traits.

Post-2023 Türkiye earthquake risk assessment of cascade dams in upper Euphrates basin

The southeastern region of Türkiye faced two significant earthquakes on February 6, 2023, causing widespread destruction and substantial damage to various infrastructures. Over forty large dams in the region were affected, leading to potential new earthquake-prone areas due to energy accumulation in neighboring regions. This study focuses on the seismic risk of eight cascade dams on the Peri River, a tributary of the Euphrates main river, following these earthquakes. The dams, including Kalecik, Kigi, Konaktepe, Ozluce, Pempelik, Seyrantepe, Tatar, and Uzuncayir, with heights ranging from 31 m to 146 m, are situated in a region influenced by the North Anatolian Fault Zone. The research advocates for a comprehensive re-analysis of certain large dams, considering the updated seismic specifications and seismological maps of Türkiye. The study explores the hazard and overall risk assessment of these dams, emphasizing the cascade system and highlighting the critical seismic vulnerabilities of Kigi and Ozluce dams, with a particular focus on their implications for water security in the region. Our findings underscore the need for tailored safety measures for each dam, focusing on early defect detection. By adopting a proactive stance and implementing our recommendations, the resilience of these dams can be enhanced, contributing to the overall water security of the region.

Effects of large dams on the aquatic food web along a coastal stream with high sediment loads

The contribution of two basal energy sources – detrital organic matter and primary producers – as part of aquatic food webs varies typically along river continua. A host of barriers to river flow increase the water residence time and sediment and nutrient retention in reservoirs worldwide, and potentially alter the balance between detritus-based and algae-based energy pathways in the downstream food webs. We explored this issue on the Sélune River (Normandy, France), a small coastal stream that drains an agricultural catchment with high sediment runoff. Seasonal measurements of the following parameters were compared upstream and downstream of the reservoirs of two large dams (16 m and 36 m high): sediment fluxes, nutrient and chlorophyll a concentrations, algal communities in the epilithic biofilm (taxonomic composition, biomass and growth), and benthic invertebrate communities (abundance and trophic guild structure). As anticipated, annual sediment fluxes were much lower downstream of the reservoirs, where significant decreases in water turbidity, phosphate and silicate concentrations were recorded. A higher chlorophyll a concentration in water and a higher contribution of pelagic algae taxa to the photosynthetic biofilm suggested drifting and deposition of reservoir-borne phytoplankton downriver. Photosynthetic biofilm growth was higher downstream of the reservoirs in spring and fall, and so was the abundance of herbivores in the invertebrate community, notably scrapers and algae eaters. Energy pathways within riverine food webs were traced using stable isotope analyses of carbon (C) and nitrogen in the tissues of aquatic consumers (invertebrates and fish). Mixing models revealed a discontinuity in the origin of the C entering the food webs along the river continuum, confirming a greater contribution of algal C to aquatic consumers downstream of the reservoirs. These results illustrate mechanisms whereby large reservoirs can modulate C flow in food webs along a small coastal river with high sediment loads, and make it possible to anticipate the effects of dam removal on the future river ecosystem.

Groundwater levels, climate and anthropogenic factors affect the hydrology and water quality of an intermittent and a regulated subtropical stream

AbstractStream hydrology and water quality are highly interconnected and impacted by climate, land use and geology. We examined this connection using monitoring data from 2000 to 2019 for two streams with contrasting hydrological regimes—intermittent and regulated perennial—in subtropical Queensland, Australia. Our main objective was to evaluate relationships between groundwater levels, climate and flow regulation on the hydrology and water quality of an intermittent and a regulated subtropical stream. In intermittently flowing Lockyer Creek, flow was highly dependent on groundwater levels and occurred when the aquifer was recharged to elevations exceeding the upper 90‐percentile value. With 9.4% of the catchment area in irrigated horticulture, flow in Lockyer Creek was also likely to be reduced by drawdown of the aquifer for irrigation, with no flow for 30% to 81% of days over the observation period for stations in Lockyer Creek. In contrast, flow in the mid‐Brisbane River was continuous, regulated by discharge from a large upstream dam. Nutrient and suspended sediment concentrations in Lockyer Creek were generally higher than in the mid‐Brisbane River, likely associated with runoff from agricultural areas adjacent to the stream, while the upstream dam likely reduced the concentration and variability of nutrients and suspended sediment in the mid‐Brisbane River. During periods of low flow in the mid‐Brisbane River, longitudinal changes in nutrient and suspended sediment concentrations occurred, notably a significant decrease in total and dissolved inorganic nitrogen concentrations downstream (p &lt; 0.05), indicating a possible effect of in‐stream algal uptake and denitrification. This study highlights the impact of human modifications on stream hydrology and water quality in the face of climate change. The findings can inform decision‐making on groundwater irrigation or dam release control for water security.

“Seeing power” between young people and conservation professionals in the design of a community-based watershed monitoring initiative

ABSTRACT Background Community-based monitoring provides a forum for diverse stakeholders to co-construct knowledge relevant to building social-ecological resilience. However, power asymmetries between these actors can privilege the perspectives of dominant groups, while preventing non-dominant perspectives from informing conservation science. Methods This study investigates a workshop series intended to support young people in designing a watershed monitoring initiative rooted in their own interests with respect to a large dam removal in their community. We use interaction analysis to examine whose ideas are taken up in discussions among young people, educators, conservation professionals, and education researchers. Findings Power dynamics that privilege the contributions of credentialed professionals over those of young people can constrain collective learning processes while simultaneously generating tensions that allow for expansive learning to occur. Facilitation practices and other pedagogical moves play an important role in either further entrenching or disrupting hierarchies between youth and community partners. Contribution Our analysis reveals how careful attention to interactional dynamics—both as a research method and as a pedagogical practice—can make visible and disrupt epistemic hierarchies in multi-stakeholder learning environments. Problematizing these hierarchies can help broaden the perspectives from which knowledge is generated, a necessary endeavor in building resilient social-ecological systems.

The selection parameter for the operation and maintenance dam based on activity-based costing

Potential risks to people exist if a dam collapses and has a significant impact on the downstream area. Many countries are now facing the problem of having to deal with deteriorated infrastructure due to a lack of maintenance budgeting. This paper presents the dominant parameter in an Operational and Maintenance (OM) dam to build a cost estimation model to maintain the service life of the dam. The method used to identify cost-triggering parameters is based on activity-based costing and dam performance assessments using a combination of the modified Andersen, International Commission of Large Dams (ICOLD), and Dam Commission. The parameter was collected from fourteen independent variables, namely: dam height, irrigation area, sedimentation volume, grass area, wood vegetation area, corrosion area, concrete area, daily worker, corrosion expert, concrete deterioration, hydromechanical, physical performance, operation performance, and safety performance. The results of the model indicate that height, wood vegetation area, concrete maintenance area, hydromechanical deterioration, and safety performance are variables that affect OM costs. The OM costs can be reduced if the safety performance variable increases. This condition implies that if the safety performance component consists of dam monitoring activities, periodic inspections, green belt maintenance, water quality maintenance, and public awareness, the OM costs will decrease by 10%.

Convolutional Neural Networks Facilitate River Barrier Detection and Evidence Severe Habitat Fragmentation in the Mekong River Biodiversity Hotspot

AbstractConstruction of river infrastructure, such as dams and weirs, is a global issue for ecosystem protection due to the fragmentation of river habitat and hydrological alteration it causes. Accurate river barrier databases, increasingly used to determine river fragmentation for ecologically sensitive management, are challenging to generate. This is especially so in large, poorly mapped basins where only large dams tend to be recorded. The Mekong is one of the world's most biodiverse river basins but, like many large rivers, impacts on habitat fragmentation from river infrastructure are poorly documented. To demonstrate a solution to this, and enable more sensitive basin management, we generated a whole‐basin barrier database for the Mekong, by training Convolutional Neural Network (CNN)–based object detection models, the best of which was used to identify 10,561 previously unrecorded barriers. Combining manual revision and merged with the existing barrier database, our new barrier database for the Mekong Basin contains 13,054 barriers. Existing databases for the Lower Mekong documented under ∼3% of the barriers recorded by CNN combined with manual checking. The Nam Chi/Nam Mun region, eastern Thailand, is the most fragmented area within the basin, with a median [95% CI] barrier density of 15.53 [0.00–49.30] per 100 km, and Catchment Area‐based Fragmentation Index value, calculated in an upstream direction, of 1,178.67 [0.00–6,418.46], due to the construction of dams and sluice gates. The CNN‐based object detection framework is effective and potentially can transform our ability to identify river barriers across many large river basins and facilitate ecologically‐sensitive management.

A Half-Century of Human Impact on Nan River Runoff and Sediment Load Supplied to the Chao Phraya River

The construction of large dams in the upper tributary basin of the Chao Phraya River (CPR) has been linked to a significant decrease in sediment load in the CPR system, estimated between 75–85%. This study, utilizing historical and recent river flow and sediment data from 1922 to 2019, examines the impact of three major dams constructed in the Nan River basin (the Sirikit, Naresuan, and Khwae Noi dams) on river runoff and sediment loads in the CPR. The investigation employed the Mann–Kendall (MK) test and the double mass curve (DMC) for analysis. Findings indicate that the Nan River is a major contributor to the CPR, accounting for around 40% of the runoff and 57% of the total sediment load (TSL). The Naresuan diversion dam’s water regulation was found to significantly reduce annual runoff and TSL downstream of the dam. Despite an initial increase in sediment load at the CPR headwater (C.2) post the construction of the Sirikit dam, attributed to expanded irrigation downstream and channel improvements in the lower Nan River, the operation of the three dams eventually led to a 31% reduction in sediment load at C.2 compared to pre-construction levels.

Ethnographic Observations of the Wartime Everyday Life of the Population of Southern Ukraine: Post-Expedition Reflections

Based on field materials, an attempt has been made to analyze the state of self-awareness among modern residents of the former centre of freedoms of the Zaporizhzhian Army, which included parts of the present-day Dnipropetrovsk and Kherson regions. The transformations taking place in this socio-cultural space and their influence on self-identification processes are traced from an anthropological perspective. Examples of russian imperial attitude towards the cultural landscape of the southern Naddniprianshchyna in different historical periods are provided. Parallels are drawn with the testimonies of the renowned traveller and ethnographer, Alexander Afanasyev-Chuzhbinsky, who, in the mid‑19th century, exploring the region and noted negative trends regarding the economic practices of the new owners of Zaporizhzhia lands. It is argued that a similar destructive impact on nature and culture was the practice of constructing large dams on the Dnipro River during the Soviet period, which generated a distinct conflict between russian imperial and Ukrainian worldviews. Through the prism of the author’s collected testimonies during expeditions to the places of the Cossack Great Meadow visited by A. Afanasyev-Chuzhbinsky, contemporary events during the russian-Ukrainian war are comprehended. The focus is on the issue of the new genocide and ecocide brought by the occupiers to the south of Ukraine as a result of the explosion of the Kakhovka Hydroelectric Power Station. The study reveals family strategies for preserving cultural memory concerning the former landscape and the role of the Zaporizhzhian Cossacks in modern processes of self-identification, through which not only the indigenous inhabitants but also participants of new waves of migration mentally assimilated the Zaporizhzhia heritage. Consequently, the military component of the cultural landscape of the Southern Naddniprianshchyna under the new conditions of the russian-Ukrainian war is capable of indirectly influencing the Ukrainian society. All of this calls for active protective measures regarding the cultural heritage and further comprehensive organization of scientific research in various fields of natural and socio-humanitarian sciences in order to preserve the values of the region and the development of Ukraine as a whole.

Quantifying modeling uncertainties in seismic analysis of dams: Insights from an international benchmark study

AbstractAdvances in nonlinear dynamic analysis of dams have not completely resolved concerns over modeling confidence and analysis accuracy. Verification and validation offer accuracy assessment, but uncertainties persist during performance evaluation due to both epistemic (modeling) and aleatory (parametric) sources. Epistemic uncertainties arise from simplifications and modeling techniques. This paper addresses epistemic uncertainties in a gravity dam seismic analysis using data from the International Comnission on Large Dams (ICOLD) benchmark study. While the benchmark formulation included the finite element model of the dam, mechanical material properties, and dynamic loads, participants retained the flexibility to opt for best‐practice modeling assumptions, simplifications, and other specifics. Notable response variability emerged, particularly in crack profiles and damage predictions. This study examines sources of variability, quantifying modeling uncertainty for the benchmark problem. More specifically, the modeling variability is quantified using the logarithmic standard deviation, also known as dispersion. This metric enables its incorporation into other seismic risk assessment and fragility studies. Under relatively low‐intensity motion (peak ground acceleration [PGA] of 0.18 g in this case), modeling dispersion of 0.45, 0.30, 0.32, and 0.30 were calculated for the maximum dynamic crest displacement, maximum hydrodynamic pressure at the heel, heel and crest maximum acceleration, respectively. Additionally, the dispersion of the failure PGA was determined to be 0.7. Findings underscore the need for systematic seismic response modeling in dam engineering to enhance prediction accuracy. A better understanding of the sources and magnitudes of modeling uncertainties can help improve the reliability of dam seismic analysis and contribute to the development of more effective risk assessment and mitigation strategies.