Impact Of Dams Research Articles

The Impacts of Beaver Dams on Groundwater Regime and Habitat 6510

Changes in land usage, increasing climatic uncertainty, and dynamic development of the rate of natural population growth of the Eurasian beaver will lead to increasing benefits and disadvantages from beaver activity. During three growing seasons from 2020 to 2022, four cross-sections were marked on unused sub-irrigation systems with the periodic occurrence of beaver dams, located on organic soils in parts of the facility protected by the Habitats Directive (natural habitat 6510) in Central Poland. Periodic water table measurements in wells, the beds of adjacent ditches, and the riverbed were carried out. Identification of the states and structures of plant communities was done using the botanical-weight analysis of several samples with an area of 1 m2. Beaver dams increased water levels in the river, ditches, and groundwater depth in over 78% of events in 2020–2022 years. A large impact of precipitation on the hydraulic conditions in the meadow was observed. In the studied area, since a moderately moist habitat (6510) is protected within the Natura 2000 network, phenomena increasing soil moisture, in the absence of mowing of meadows and the occurrence of expansive herbaceous vegetation that tolerates increased moisture, may lead to the disappearance of these habitats, especially in the zone near the riverbed.

ASSESSMENT OF THE IMPACT OF GURARA DAM ON LAND USE/LAND COVER IN THE SURROUNDING COMMUNITIES OF KACHIA LOCAL GOVERNMENT AREA OF KADUNA STATE, NIGERIA

The study assessed the impact of Gurara Dam on land use/land cover changes (LULCC) in the Kachia Local Government Area of Kaduna State. The study made use of geospatial techniques to assess the impact of the dam on land use/land cover changes within the period of study. Landsat data from 2001, 2012 and 2022 were acquired and processed to produce the land use/land cover maps of the area. The identified land use/land cover in the area were Built-up areas, Water bodies, Vegetation, bare land, and Rock outcrops. The Annual rate in land use/landcover changes was analyzed and the result revealed that, during the period 2001-2012, and 2012-2022 water bodies increased at an annual rate of 242% and 97% but reduced at an annual rate of 0.9%between 2012 and 2022. The analysis revealed that all the land use/land cover types identified in the study area recorded a net gain except vegetation. Water bodies gained about 5480 ha from 2001 to 2022. The study concluded that the construction of the Dam has altered the land use land cover dynamics of the area and there is also evidence of deforestation in the study area. The study recommends the control of land use in the basin and uses it as a guide to help in prioritizing the management of the basin and the dam among others.

Greenhouse gas concentrations and diffusive fluxes in the middle reach of the Lancang River before and after damming

With increasing concerns of greenhouse gas (GHG) emissions from reservoirs, the debate surrounding whether hydropower qualifies as green energy has become increasingly contentious. However, quantifying the impact of dam construction on river GHG emissions still poses challenging due to the absence of direct observational data on river GHG emissions pre- and post-damming. In the present study, the differences in GHG diffusive fluxes from pre- and post-dammed river channels in the middle reaches of the Lancang River were quantified through three field campaigns in 2016, 2018, and 2023. The results indicate that reservoir construction increases the diffusive fluxes of GHG from the natural river, the total GHG emissions (expressed as carbon dioxide equivalent: CO2eq) from post-dammed river ranged from 234.42 to 527.55 mg CO2eq m−2 d−1 and were 1.4–5.2 times higher than that from pre-dammed river. However, the GHG diffusive fluxes from the reservoirs in the Lancang River remain below the average of global reservoirs. Moreover, river damming enhances the methane (CH4) emissions, the average value of CH4/CO2 ratio (in mg m−2 d−1) was 0.003 post-dam and was 13 times higher than that of pre-dam. Our results revealed that alterations in sediment distribution following reservoir construction emerge as a pivotal factor contributing to the variations in spatial distributions of GHG diffusive fluxes in the studied river channel. Overall, the findings of the study provide a primary and direct evidence of river damming impact on GHG emissions and underscore the necessity of long-term continuous in-situ measurements of GHG fluxes in the rivers undergoing hydropower development.

Dam Impact on Fish Assemblages Associated with Macrophytes in Natural and Regulated Floodplains of Pandeiros River Basin

Dam Impact on Fish Assemblages Associated with Macrophytes in Natural and Regulated Floodplains of Pandeiros River Basin

Fish community dynamics following the low-head dam removal and newly installed fish passage in a headstream tributary of Jinsha River, Southwest China

Low-head dams and small hydropower developments are widely distributed in global rivers because of their high cost-efficiency and smooth implementation. However, these installations have great ecological impacts on native fish communities due to the loss of longitudinal river connectivity. Although dam removal and fishway construction are effective measures to mitigate river fragmentation, research on their effects on fish communities remains limited to date. In this study, we investigated fish community dynamics in a mountainous tributary of the Jinsha River–Heishui River following dam removal, fishway construction, and fishway renovation. Our fish sampling data from 2018 to 2023 yielded 6137 fish belonging to 25 species, 12 families, and 3 orders. The native fish community predominantly represented the typical fish fauna of the Qinghai-Tibetan Plateau, primarily including the genus Schizothorax and the families Sisoridae and Nemacheilidae. Representative fish species in the Heishui River demonstrate notable adaptations to cold water, high altitude, and rapid flow environments. After removing the Laomuhe Dam, upstream fish abundance increased sharply, but species richness slightly decreased in the short term. Fishway construction significantly enhanced species richness and abundance and reduced the difference between the upstream and downstream fish communities from the Songxin Dam. However, the subsequent fishway renovation altered the dominance of fish species, with marginal changes in community structure and abundance. Variations in fish community dynamics in the river channel and fishway structure can be attributed to differences in ecological guilds (e.g., flow preference and thermal regime) and environmental factors (e.g., flow discharge, water temperature, and water depth). The present study provides insight into the significance of mitigation measures for the impact of dams on mountainous rivers in southwest China through ecological assessment and guides for decision-making in the conservation and restoration of specific fish communities.

Dam Size Variations Influence Dam Impacts and Potential Benefits of Dam Removal

Dam Size Variations Influence Dam Impacts and Potential Benefits of Dam Removal

PSIV-6 Blood biomarkers of oxidative stress in offspring from dams infected with bovine viral diarrhea virus during late-term gestation

Abstract The objective of this experiment was to examine the impact of dams infected with bovine viral diarrhea virus (BVDV) during late gestation on inflammatory blood biomarkers in their offspring. Fetal infection with BVDV before d 125 to 150 of gestation results in the birth of immunotolerant, persistently infected (PI) calves. Infection of BVDV during late gestation results in transient fetal infections (TI). It was hypothesized that offspring of dams transiently infected with BVDV on d 175 of gestation would have greater inflammatory blood biomarkers than control offspring. Unvaccinated, yearling Hereford heifers (n = 24), seronegative for antibodies to BVDV1 and BVDV2 were bred by artificial insemination with X chromosome-bearing sperm from an Angus sire. On d 175 of pregnancy, heifers were intranasally inoculated with either Dulbecco’s Modified Eagle Medium + 2% horse serum (sham control) or 4.0 log TCID50 noncytopathic type 2 BVDV to generate control and transient infected calves, respectively. All BVDV-inoculated dams seroconverted by d 14 post-inoculation and all sham-inoculated control dams remained seronegative. Twelve, seronegative control heifer calves were born to the control dams, and 11 seropositive (to type 2 BVDV) TI heifer calves were born to BVDV-inoculated dams. All offspring were raised on pasture until weaning. At weaning, all calves were transported to our feedlot research facility, housed in one group feedlot pen, and transitioned to a high-energy concentrate-based diet until reaching an approximate body weight (BW) of 600 kg. Upon arrival, all animals received a standard heifer growth implant containing 200 mg of testosterone propionate and 20 mg of estradiol benzoate, a modified live viral vaccine containing IBR-BRSV-PI3, and were dewormed. Jugular blood samples were obtained every 28 d until harvest (280 d on feed) and analyzed for biomarkers of inflammation. Data were analyzed as a randomized block design with the MIXED procedures of SAS. There was a treatment x time interaction (P < 0.05) for plasma ceruloplasmin and the oxidized form of glutathione. On d 0 and 28 of the feeding period, all biomarkers were similar across treatments. By d 56 of the feeding period, ceruloplasmin (P < 0.03) and the oxidized form of glutathione (P < 0.01), indicators of chronic inflammation, were increased in plasma samples from TI heifers compared with controls. These parameters remained greater in TI heifers compared with controls throughout the feeding period. There were no treatment or treatment x time interactions for plasma interferon (INF)-γ, tumor necrosis factor (TNF)-α, interleukin (IL)-6, and haptoglobin. These data suggest that TI heifers may be experiencing a greater level of oxidative stress later in the finishing period. This research was supported by USDA-NIFA Grant #2019-67015-29866.

228 Evaluation of sire vs. dam influences on age at first parturition in Brahman heifers

Abstract The objective of this study was to determine if sire or dam had a stronger impact on age at first parturition of Brahman heifers (n = 833) born between 2000-2021. Typically, in Bos taurus heifers, puberty occurs between 10 to 12 mo of age leading to parturition of the first calf occurring around 24 mo of age. However, in Bos indicus cattle, puberty is achieved between 15 to 17 mo of age leading to a first calf around 36 mo of age. The ability of heifers to achieve pubertal status earlier plays a vital role in reproductive success. For selection purposes, knowing if early pubertal attainment is influenced more by the sire or dam is important for herd management. For this study, to minimize any epigenetic and environmental changes, all heifers originated and were developed at the Texas A&M AgriLife Research Center at Overton. Sire groups (SG) and dam groups (DG) were established based on the number of offspring used in the study. Sire groups were comprised of SG-1 (1+ calves sired; n = 58 sires), SG-2 (5+ calves sired; n = 44 sires), SG-3 (10+ calves sired; n = 31 sires), SG-4 (15+ calves sired; n = 23 sires), SG-5 (20+ calves sired; n = 17 sires), and SG-6 (25+ calves sired; n = 12 sires). Dam groups consisted of DG-1 (1+ calves; n = 489 dams), DG-2 (2+ calves; n = 215 dams), DG-3 (3+ calves; n = 81 dams), DG-4 (4+ calves; n = 38 dams), and DG-5 (5+ calves; n = 9 dams). Statistical analysis (PROC GLM; SAS 9.4) included the fixed effect of sire group (dam group) and all dams (sires) utilized in that grouping. Significance for age at first calving was considered at P < 0.05. Mean separation for age was performed using LSmeans. Sire significantly impacted age at first calving in SG-1 (P = 0.0173) vs dam effect (P = 0.3993; n = 489 dams), SG-2 (P = 0.0159) vs dam effect (P = 0.5476; n = 481 dams), SG-3 (P = 0.0023) vs dam effect (P = 0.2532; n = 439 dams), SG-4 (P = 0.0022) vs dam effect (P = 0.3997; n = 400 dams), SG-5 (P = 0.0002) vs dam effect (P = 0.0602; n = 361 dams), and SG-6 (P = 0.0005) vs dam effect (P = 0.1058; n = 305 dams). The dam impact on age at first calving was never significant in the dam groupings but sires did impact age at first calving in two groups: DG-1 (P = 0.3993) vs sire effect (P = 0.0173; n = 58 sires), DG-2 (P = 0.4823) vs sire effect (P = 0.0173; n = 56 sires), DG-3 (P = 0.3011) vs sire effect (P = 0.3420; n = 49 sires), DG-4 (P = 0.3911) vs sire effect (P = 0.6278; n = 40 sires), and DG-5 (P = 0.3042) vs sire effect (P = 0.9159; n = 23 sires). In summary, evaluation of sire and dam influences on age at first parturition for female offspring demonstrates that the ability to calve at an earlier age is influenced by the sire but not the dam. Further studies into the mechanisms for the transmission of this trait are warranted.

Quantifying the impact of dams on global streamflow over the period of 1985–2014

Quantifying the impact of dams on global streamflow over the period of 1985–2014

Dam-Break waves over mobile bed

Dam-break waves are a major concern for communities and infrastructures in flood-prone areas. The impact of dam-break waves against rigid obstacles after propagation on a mobile bed is lacking both in experimental datasets and in numerical investigations aimed at assessing the capabilities and limitations of available morphodynamic models. To fill these gaps, a novel data set from experiments of dam-break waves propagating over an erodible bottom and impacting over a vertical wall is presented and compared with numerical simulations performed by the Saint Venant–Exner model. First, the effects of bottom mobility are discussed by comparison with the corresponding fixed bed condition. Then, supplementary conditions are investigated for different initial water levels and reservoir lengths. The comparison with the results of the numerical simulation shows that the relatively simple model employed is able to reproduce the general features of the process and the peak impact force with reasonable accuracy.

How do hydroelectric dams affect non-migratory fish?: genomic evidence for Cichla temensis (Perciformes: Cichlidae) in the Uatumã River, Amazonas, Brazil

Abstract The Balbina hydroelectric dam was built in the 1980s on the Uatumã River to supply electricity to Manaus, capital of the state of Amazonas, Brazil. Its construction caused a drastic change to the alluvial landscape, forming a large, lentic, artificial reservoir rather than a previously dynamic river system. The objective of our research was to evaluate the impact of the hydroelectric dam on the microevolutionary processes of fish, taking as a model Cichla temensis, an iconic non-migratory fish from the Amazon, abundant in this ecosystem. We collected double digest restriction site-associated DNA sequencing data and extracted single nucleotide polymorphisms, which we identified at neutral and adaptive loci, for subsequent analyses. The results showed that the connectivity of the population was affected historically by natural physical barriers, before the construction of the hydroelectric dam, recognizing two independent population units. We detected that the hydroelectric dam increased the differentiation between populations and affected the genetic diversity and effective population sizes, in addition to promoting a recent population expansion upstream of the dam, as a consequence of adaptation to the new environment. This study provides the first evidence that hydroelectric dams can promote local adaptation in some fish, such as non-migratory ones.

Evaluating the Impact of Mini Dams on Agricultural Production and Socio-economic Conditions: A Case Study of Latamber’s Dam District Karak (Pakistan)

Water scarcity is an escalating global concern, and Pakistan is no exception, facing increasing water crises and growing demand. Effective water supply is crucial for the development of any area. Mini dams not only provide water for irrigation but also support domestic uses. This study evaluates the impact of mini dams on agricultural productivity in Latamber village, focusing on crop yield, land use and land cover (LULC) changes, and socio-economic conditions. A multifaceted methodology, including field surveys, departmental data collection, questionnaires, and remote sensing, was employed. Data collected through questionnaires and farmer interviews highlighted the economic and environmental benefits of mini dams. Statistical analysis and image processing revealed significant expansions in cultivation areas for crops like maize and rice, alongside increases in wheat yield and the adoption of new vegetable crops during the Rabi season. Additionally, socioeconomic benefits, such as enhanced agricultural incomes and employment opportunities, were observed due to improved water availability and irrigation technologies. The study emphasizes the importance of evaluating the impact of mini dams on agricultural production and socio-economic conditions to inform sustainable water resource management strategies, which are vital for the long-term development of similar regions.

Sharp decline in surface water resources for agriculture and fisheries in the Lower Mekong Basin over 2000-2020

Water resources play a crucial role in the global water cycle and are affected by human activities and climate change. However, the impacts of hydropower infrastructures on the surface water extent and volume cycle are not well known. We used a multi-satellite approach to quantify the surface water storage variations over the 2000–2020 period and relate these variations to climate-induced and anthropogenic factors over the whole basin. Our results highlight that dam operations have strongly modified the water regime of the Mekong River, exhibiting a 55 % decrease in the seasonal cycle amplitude of inundation extent (from 3178 km2 to 1414 km2) and a 70 % decrease in surface water volume (from 1109 km3 to 327 km3) over 2000–2020. In the floodplains of the Lower Mekong Basin, where rice is cultivated, there has been a decline in water residence time by 30 to 50 days. The recent commissioning of big dams (2010 and 2014) has allowed us to choose 2015 as a turning point year. Results show a trend inversion in rice production, from a rise of 40 % between 2000 and 2014 to a decline of 10 % between 2015 and 2020, and a strong reduction in aquaculture growth, from +730 % between 2000 and 2014, to +53 % between 2015 and 2020. All these results show the negative impact of dams on the Mekong basin, causing a 70 % decline in surface water volumes, with major repercussions for agriculture and fisheries over the period 2000–2020. Therefore, new future projects such as the Funan Techo canal in Cambodia, scheduled to start construction at the end of 2024, will particularly affect 1300 km2 of floodplains in the lower Mekong basin, with a reduction in the amount of water received, and other areas will be subjected to flooding. The human, material and economic damage could be catastrophic.

The Impacts of Dams on Streamflow in Tributaries to the Lower Mekong Basin

The Lower Mekong Basin has had extensive hydropower dam development, which changes its hydrologic conditions and threatens the exceptional aquatic biodiversity. This study quantifies the degree of hydrologic change between pre-impact (1965–1968) and post-impact (2018–2021) peak hydropower development in two major tributaries of the Lower Mekong Basin—the Sekong River, with the fewest dams, and the Sesan River, with the most dams. Both rivers have historically supported migratory fishes. We used daily pre- and post-impact data and the Indicators of Hydrologic Alteration framework to evaluate streamflow changes from dam development. We found significant changes in low- and high-magnitude flows in the pre- and post-impact periods of dam development. For the Sekong River, minimum flow had large fluctuations, with increases of 290% to 412% compared to the pre-impact period, while the Sesan River’s minimum flow ranged from 120% to 160% more than pre-impact. Dry season flows increased by 200 ± 63% on average in the Sekong River, which was caused by releases from upstream dams. Meanwhile, the Sesan River’s dry season flows increased by 100 ± 55% on average. This study indicates that seasonal flow changes and extreme flow events occurred more frequently in the two basins following dam construction, which may threaten the ecosystem’s function.

Evaporation from dams governing the water cycle dynamics of a regulated river basin from the Western Ghats: Sharavati, India

Study regionSharavati River, Karnataka, India. Study focusA small mountainous river system, Sharavati, was selected to study the impact of river damming on the hydrological cycle. Sharavati river flow is regulated by two dams, Linganamakki and Gersoppa. Despite the Western Ghats' global significance in controlling local and regional climates, the effects of damming on its hydrological cycles have received limited attention. A stable water isotopic approach was employed in the study. New hydrological insights for the regionThe line-conditioned excess (lc-excess) was primarily negative across all seasons. Notably, the pre-monsoon season exhibited comparatively higher evaporation with high negative lc-excess, while the postmonsoon lc-excess values approached zero, indicating minimal evaporation. The sampling points from the dams exhibited very high evaporation signals, the evaporative loss during the pre-monsoon season from the Linganamakki reservoir was estimated as 10 %, and from the Gersoppa dam was 6 %. Consequently, groundwater sampled near the dams, plotted along the local evaporation line indicating recharge from the evaporated reservoir water. Damming has affected the hydrological cycle of the heavily regulated Sharavati River, transforming the entire catchment into a connected, narrow lake-like structure, especially during the pre-monsoon season. Since the Western Ghat river systems are regulated by many large and small dams, it is pertinent to study the impact of damming on the hydrological cycles of the entire system.

Effects of repeated drawdown flushing on riverbed fine sediment dynamics downstream from a dam

Sediment accumulation in reservoirs is frequently a problem, impelling dam managers to implement strategies such as drawdown flushing to limit siltation. Drawdown and other sediment removal methods may induce riverbed clogging downstream of dams, especially in river sections where water is diverted, thereby reducing transport capacity. In this study, we investigate the effects of drawdown flushing downstream of the Plan d’Arem run-of-the-river dam (Upper Garonne, Spain – France border) using an adaptive inter-site comparison strategy to consider a range of spatial and temporal conditions, which allow us to separate the effects of dam storage and flushing from other potential factors. Drawdown flushing has been undertaken three times during the study period over a short span of time (2 months). We couple bed material sampling, which provides direct information on bed composition, with airborne infrared thermal imaging to better interpret whether fine sediment interstitial storage within the bed is associated with clogging. We also measure bed surface grain size and bed mobility in order to investigate their potential role in controlling fine sediment dynamics. We identify surface grain size and water diversion as the main factors controlling fine sediment spatial distribution, with coarse-grained bed-surfaces and by-passing promoting fine sediment enrichment. As a result, sites located upstream and within the by-passed reached of the Plan d’Arem dam show higher fine sediment interstitial storage than sites downstream from the by-passed reach. Results from thermal imagery demonstrate such interstitial storage does not induce clogging effect. The reaches with the most important sediment storage host a high number of cool-water patches, indicating water exchanges with the hyporheic zone. Post-flushing bed composition indicates systematic export of fine sediments from the bed matrix at all sites after the first operation, afterwards fine levels remain low after the second and the third flushing. The low impact of dam flushing in term of clogging is interpreted by the fact that the interstitial material is very sandy.

Economic life evaluation of reservoir dams based on comprehensive costs and benefits analysis considering potential dam breach: A case study of the Luhun reservoir in China

The scientific evaluation of a dam’s economic life is necessary to determine its management strategy rationally. However, most studies have mainly focused on analyzing the current economic characteristics of reservoir dams without considering their long-term development trend. And they have failed to incorporate the potential loss caused by dam breaches as one of the operating costs for dams. Consequently, this results in the inability to scientifically calculate the economic life of reservoir dam operations. Therefore, this study analyzed the factors influencing the economic life of reservoir dams in term of safety, costs, benefits and society, and established an economic life evaluation indicator system for reservoir dams. Based on the analyses of costs and benefits of reservoir dams, an economic life evaluation model for reservoir dams was constructed by comprehensively considering the impact of potential dam breaches and the social impact of reservoir dams on the production and lives of local residents. Moreover, based on economic theory, the economics of various types of management measures for reservoir dams and their impact on the economic life of dams were analyzed. The proposed model was applied to the Luhun Reservoir in Henan Province, China, to quantify the comprehensive costs and benefits of its operation for each year after 1990 s, analyze the trend of its “cost-benefit” relationship, and calculate its expected economic life. The results showed that when considering its own risks and social impacts, the expected economic life of the Luhun Reservoir was 74 years. The Luhun Reservoir is expected to operate up to its non-economic life span till 2039. Finally, suggestions for expanding the economic life of dams were proposed. Potential dam breach losses can significantly reduce the economic life of reservoir dams. And risk management measures for reservoir dams should be particularly strengthened during daily operations and management.

Hydro‐thermal modelling of the potential impacts of reservoirs on water temperature and incubation time of Atlantic salmon and brook trout in the Tobique River, Canada

AbstractWater temperature is recognised as a crucial variable in lotic ecosystems affecting the metabolism of aquatic organisms, with extremely high‐temperature events increasing the risk of mortality of various species. Impounding rivers to regulate flow and generate electricity is one of the causes of altered thermal regimes in river systems. This paper presents the results of a study to simulate the impact of reservoirs on downstream temperatures of the Tobique River, New Brunswick, Canada. CEQUEAU, a hydrological and water temperature model, was used to simulate and assess the flow and water temperature of the Tobique River from 1997 to 2020. It was coupled to a statistical model to generate water temperature at different depths in the reservoir. Results show that the CEQUEAU model was successfully calibrated for water temperature with an overall root mean square error of 1.7°C. Based on the results, when water is drawn from the lower parts of the reservoir, the mean water temperature downstream of the dam increases in winter and spring by ~1°C. The results of this paper provide insight into how dams can affect the incubation time of cold‐water species in eastern Canada. We calculated the hatching degree days of Atlantic salmon and Brook trout to evaluate the impact of dams on fry emergence. Results indicated that the hatching period of Atlantic salmon and Brook trout downstream of reservoirs may shorten under the influence of dams.

Impacts of large dams on Amazonian floodplain bird communities

Impacts of large dams on Amazonian floodplain bird communities

Carbon Emissions and Vegetation Dynamics: Assessing the Spatiotemporal Environmental Impacts of Hydropower Dams in the Lancang River Basin

Recent decades in the Lancang River Basin have witnessed extensive construction of hydropower dams, profoundly impacting the local environment. Utilizing high-precision satellite data, we conducted a comprehensive analysis of vegetation cover and carbon emissions, integrating data-driven time series and spatial analysis models to capture both temporal and spatial dynamics. Our findings reveal that hydropower dam construction in the Lancang River Basin has significantly promoted vegetation restoration and growth, concurrently facilitating a reduction in regional carbon emissions. Employing deep learning models for time-series prediction, we observed a substantial increase in the sum of the local normalized difference vegetation index (NDVI) post-construction, with an average rise of from 16.15% to a maximum of 20.12% during the pivotal hydropower dams’ operational phase. Between 2001 and 2020, the construction of hydropower dams in the basin corresponded to notable changes in ecological and carbon metrics. Specifically, vegetation cover expansion intensity (VCEI) reversed from a negative mean of −0.009 to a positive mean of 0.008. Additionally, the carbon emission intensity (CEI) around these dams drastically reduced, shifting from an average of 0.877 to 0.052. Importantly, the Global Moran’s I for VCEI significantly increased from 0.288 pre-2016 to 0.679 post-2015, reflecting a stronger spatial autocorrelation in vegetation patterns. Accordingly, these findings illustrate the complex interplay between hydropower dams and environmental outcomes, underscoring the critical role of pivotal hydropower dam construction in ecological improvement. The research results have improved and complemented those of previous studies on the environmental impact of hydraulic engineering, providing valuable insights for the construction management and policy formulation of hydropower dams in other similar river basins around the world.