Dam Development Research Articles

Retrofitting the Mekong: Community-based environmental responses to Chinese transnational infrastructure in a Thai border town

For decades, the Mekong River has been a site of ongoing tensions between China-backed infrastructure and communities relying on the mighty Mekong for their lives and livelihoods. In Thailand, tensions have escalated into actions against ecologically damaging hydropower dam development and the blasting of river rapids for Chinese navigation in a Thai border town. This article examines how Chinese transnational infrastructure has been reconfiguring power relationships among actors at multiple scales. Based on my fieldwork, I offer a narrative of the concerted efforts by one small community-based environmental group in northern Thailand, some of whose activism has prodded Chinese planners and project managers into responding to widespread criticism of ecological damage caused by its hydropower and riparian infrastructure and ignoring the needs of downstream local communities. The interactions between Chinese agencies and local NGOs will be discussed through the concept of a moral ecology of infrastructure, which contributes to transcending infrastructure and the environment, enabling a broadened understanding of human and nonhuman relations in more recent retrofitting of the dams and waterway projects. I argue that the reconfigured ‘Green’ Belt and Road Initiative is a contingent process in which multiple transnational actors claim decision-making power over the retrofitting and redevelopment of the Mekong's ecological infrastructure.

How sensitive are catchment runoff estimates to on-farm storages under current and future climates?

Storage of water in farm dams is important to support irrigation, stock requirements and domestic uses when reticulated water is unavailable. Farm dams that fill by intercepting landscape runoff change the total volume and seasonality of catchment streamflow, potentially impacting water policy outcomes. While numerous studies have quantified how climate change and farm dams independently change streamflow characteristics, few studies have investigated their interactions. This study investigates the interactions between farm dams and climate change in the Murray-Darling Basin of southern and eastern Australia. We use hydrological modelling that explicitly represent farm dams and remotely sensed data describing historical farm dam development to assess the impacts of farm dams for 112 catchments on catchment runoff under current and future climates. Our analysis compares current and future runoff estimates to those derived without explicitly incorporating farm dam impacts to better understand the importance of farm dams in water resources assessments.We find that modelling farm dams in these catchments improves the performance of the hydrological model relative to a traditional rainfall-runoff model ignoring the effects of farm dams. The current level of farm dam development in the Murray-Darling Basin is estimated to reduce annual catchment runoff by 13% (in the range of 8%–19%) under the historical climate across the 112 catchments investigated here. We find that explicitly modelling farm dams increases the sensitivity of simulated streamflow to climate by approximately 10%. This is primarily because farm dams introduce additional catchment storage and water extractions that do not directly follow processes represented in traditional rainfall-runoff models.Our analysis offers important information for water policymakers in Australia and globally. Firstly, explicit modelling of farm dams is critical to understanding the future availability of water resources. Secondly, explicit modelling of farm dams allows their impacts on catchment runoff to be explored under current and future climates, and for policies to manage the impacts of dams to be investigated.

Assessing the impacts of climate change and dam development on potential flood hazard and damages in the Cambodian floodplain of the lower mekong basin

Study RegionMekong River Basin Study focusClimate change has become a global environmental and socio-economical issue potentially affecting river hydrology and downstream flood characteristics. Climate change and upstream dam construction are the two main driving factors in altering the hydrology in the Mekong River Basin. Cambodian floodplain is located in the vulnerable flood zone to be affected by climate change and upstream dam development. This study investigated the potential impacts of future climate change and dam construction on flood hazards and agricultural damages in the Cambodian floodplain of the Mekong River. Climate outputs from MRI-AGCM3.2S under different sea surface temperature (SST) scenarios and a large ensemble climate dataset (d4PDF) under 4 K increasing scenario were used as input to a fully distributed rainfall-runoff-inundation (RRI) model for future projection of flood in the Lower Mekong Basin. New hydrological insights for the regionThe results indicated that the changes in extreme flood events (25-year flood) showed an increase of agricultural flood damages under climate change impact by 18–28% under different SST scenarios. These increases would be only 5–13% under integrated impacts from future climate change and dam construction. Under the 4 K increasing scenario, the agricultural damages for extreme flood events of 10-year, 50-year, and 100-year return periods would increase by 32%, 38%, and 39% for climate change impact alone and 17%, 29%, and 31% for combined climate change and dam development scenario, respectively. The climate change impacts would have more influential on increasing the magnitude of extreme floods than the reduction caused by dam reservoir constructions in the future projection in the Cambodian floodplain of the Mekong River Basin. The impact of dam constructions tends to have greater impact on reducing smaller extreme events; however, their impacts are relatively smaller for larger extreme flood events (i.e., 100-year flood).

Characterising the regional growth of on-farm storages and their implications for water resources under a changing climate

Water demand for agricultural activities has caused a growth in small on-farm storages (i.e., ≥ 0.1 ha to ≤ 10 ha) in many areas worldwide, thereby increasing the capture of landscape runoff which otherwise would enter the catchment drainage system. The cumulative effects of these on-farm storages (colloquially known as farm ponds or farm dams) can result in reduced mean annual flows, particularly during dry years. Climate change, which will very likely exacerbate extreme weather conditions including droughts, may accelerate the growth of farm dams in semi-arid agricultural areas with limited access to surface water. The aim of this study is to evaluate farm dam development and total farm dam water volumes at regional scales using Landsat water indices (WIs). The Murray-Darling Basin (MDB, 1.061 million km2) in south and eastern Australia, which has experienced a sustained growth in farm dams in the 1990s and early 2000s, is used as a case study. Using a pixel validation dataset, four WIs were trialled for their capabilities to detect the presence of water in farm dams. Of the WIs tested here, AWEIshadow showed the best performance. As a result, AWEIshadow was used to establish the year in which water was first observed (i.e., its year of commission) in 727,081 farm dams across the MDB and to calculate the total farm dam volume in the region. Farm dams’ volume in the MDB increased more than twofold between 1990 and 2020, from 1241.0 MCM (million cubic meters) to 2,629.5 MCM. The growth differed across MDB regions, generally accelerating during the ‘Millennium Drought’ (2001–2009). In the entire MDB, there was rapid development in the 1990s with 3.1% growth. Growth was 2.5% from 2000 to 2010, tapering off to 0.6% from 2010 to 2020.In Robertson et al. (this issue), the year-by-year growth in farm dams’ volume were used in a rainfall-runoff model thereby incorporating the time-varying effects of farm dams. Robertson et al. (this issue) show that explicitly modelling farm dams improves the model’s performance relative to a traditional rainfall-runoff model that ignores the effects of farm dams. Hence, this improves the capability of assessing the direct impacts of farm dams and their potential growth in climate change studies.

The Impact of Weir Construction in Korea's Nakdong River on the Population Genetic Variability of the Endangered Fish Species, Rapid Small Gudgeon (Microphysogobio rapidus).

Microphysogobio rapidus, an endemic cyprinid fish species found exclusively in Korea, has been identified in only two tributaries of the Nakdong River. The species predominantly occupies the near-gravel bottom waters within shallow sections of the middle and lower reaches of the river, characterized by swift currents. M. rapidus is currently recognized as a critically endangered species due to its distinct habitat preference, as well as the negative impacts of stream dam development and water environment pollution. In this study, we used 10 microsatellite markers to examine the genetic diversity of M. rapidus in the upper Nam (UN), lower Nam (LN), and Deokcheon Rivers (DC) in Korea, with a specific focus on assessment of the impact of dam development. Fish sampled from the UN and LN showed a greater average number of alleles and allelic richness (A = 18.3-18.4, AR = 13.8) compared to those from DC (A = 11.8, AR = 11.5). The observed heterozygosity among the fish examined ranged from HO = 0.748 (LN) to 0.766 (DC). All three fish groups exhibited a significant departure from Hardy-Weinberg equilibrium (HWE) (p < 0.05). Despite having the largest effective population size (Ne = 175 and 157, respectively), the fish sampled from UN and LN showed the highest inbreeding coefficients (FIS = 0.056-0.053, respectively), which were highly significant (p < 0.01). In contrast, the fish sampled from DC exhibited the smallest effective population size (Ne = 61) and showed an inbreeding coefficient close to zero (p > 0.05). BOTTLENECK analysis and estimated M-ratio values (0.341-0.372) revealed indications of past population size reduction in all fish groups examined. No significant genetic differentiation (FST < 0.05) was detected using the DAPC, STRUCTURE, and AMOVA among the fish studied. However, pairwise comparisons of FST between fish sampled from the Nam and Deokcheon Rivers revealed significant values (p < 0.001) ranging from 0.013 to 0.014. In addition, the closest genetic distance (0.026) was observed between UN and LN, while the greatest distance (0.087) was found between UN and DC. Analysis of gene flow rates among the fish examined indicated asymmetrical gene exchange within the Nam River, which was 31.51% in the downstream direction (from UN to LN), with a minimal gene flow rate (0.41%) in the upstream (from LN to UN) direction. The opposite trend was recorded between DC and LN, with a higher gene flow rate (29.74%) in the upstream direction compared to the downstream direction (0.12%). Our study highlighted the importance of implementing long-term conservation efforts focused on maintaining river integrity by removing water barriers such as weirs that impede fish migration and implementing active protection measures, such as aquaculture breeding and reasonable stocking practices, to preserve M. rapidus in the study area.

Analisis Produktivitas Alat Berat dan Pekerja di Pekerjaan Pengecoran Lantai Spillway pada Proyek Pembangunan Bendungan

Productivity is one of the keys to determining the factors that affect competitiveness in construction projects, including the productivity of workers and heavy equipment for spillway casting work at Dam Development. The aim of the research is to analyze productivity and factors affecting heavy equipment and workers. This research using quantitative descriptive calculation methods, and observation in field time study. The results of the data calculations show that the productivity value of a concrete pump is 167.491 m3/day, the productivity of mixer trucks is 46.305 m3/day/unit, and the productivity of workers is 13.790 m3/day/person. Factors that affect heavy equipment productivity are weather, work time efficiency, and material or payload. As well as factors that affect worker productivity, there are the weather, worker time efficiency, foundry location, and the number of workers.

The Use of Shape Accel Array for Deformation Monitoring and Parameter Inversion of a 300 m Ultrahigh Rockfill Dam

The global construction of rockfill dams has now surpassed the 300 m height level. Despite great achievements in dam design and construction, monitoring techniques have lagged behind the development of high rockfill dams. Existing deformation monitoring techniques are ill-suited to the high earth and water pressures, and extended monitoring periods are required for ultrahigh rockfill dams. This study introduces, for the first time, the use of a shape accel array (SAA) to monitor internal displacement in a 300 m high earth core rockfill dam. The SAA employs a rope-like array of capacitive MEMS accelerometers for deformation measurement. Compared to conventional monitoring techniques, SAA is a data-intensive monitoring technique. Based on the intensive data obtained from SAA, we employed a parameter inversion method, utilizing multiobjective optimization algorithm, the nondominated sorting genetic algorithm-III (NSGA-III), to inverse the constitutive model parameters of the rockfill dam. The multiobjective parameter inversion method maximizes the use of multisource monitoring data for predicting rockfill dam deformation.

Research and practice of key technologies for landslide dam development and utilization—A case in Hongshiyan landslide Dam Water Conservancy Project

AbstractBased on the emergency rescue, the subsequent disposal, and the development and utilization projects of the Hongshiyan Landside Dam in Ludian, Yunnan, China, research has been conducted on key technical issues facing the development and utilization of landside dams, including the possibilty evaluation of development and utilization, structure analysis of wide gradation material, performance evaluation, investigation and design, dam seepage control, construction technology and equipment, and safe operation assessment. And innovative results has made in all seven aspects mentioned above, writing the history in this field. The achievements were directly applied to the development planning, investigation and design, construction, and operation and maintenance of the Hongshiyan Landside Dam, a comprehensive water conservancy project that integrates flood control, water supply, irrigation, and power generation, with significant comprehensive benefits.

Balancing Sediment Connectivity and Energy Production via Optimized Reservoir Sediment Management Strategies

AbstractSediment connectivity plays a fundamental role in sustaining ecosystem goods and services in fluvial systems, including hydropower production. Dams alter the natural processes of sediment transport by trapping sediment and reshaping downstream hydrology and geomorphology. Due to these processes' interconnected nature, dams' impacts extend in time and space beyond the dam site to the entire river system. System‐scale approaches to reduce dam impacts commonly only consider dam siting, overlooking the potential of sediment management strategies integrated into the dam operations to offer more flexible solutions for mitigation. Herein, we contribute a sediment routing model (D‐CASCADE) to assess the impacts of reservoirs and their management strategies on river sediment connectivity. D‐CASCADE is applied to the 3S river system, a tributary of the Mekong River, a hotspot of potential dams in the Lower Mekong. We analyze three dam development portfolios. The effect of reservoir management is examined by assessing daily sediment delivery with specific dam release strategies. Model results predict sediment yield to the Mekong to reduce by 31%–60%. Finally, we explore trade‐offs between hydropower generation and sediment connectivity across cascades of multiple reservoirs. Results show that repeated flushing operations during the early wet season could significantly increase sediment delivery with minimal (max 6%) hydropower losses. While poor trade‐offs between sediment and hydropower have been locked‐in in the Mekong, our results highlight the potential of including sediment connectivity models in multi‐objective decision‐making frameworks to devise integrated water and sediment management strategies that mitigate connectivity disruptions while minimizing losses in other sectors.

Fish biodiversity declines with dam development in the Lower Mekong Basin

Hydropower dams are a source of renewable energy, but dam development and hydropower generation negatively affect freshwater ecosystems, biodiversity, and food security. We assess the effects of hydropower dam development on spatial–temporal changes in fish biodiversity from 2007 to 2014 in the Sekong, Sesan, and Srepok Basins—major tributaries to the Mekong River. By analyzing a 7-year fish monitoring dataset, and regressing fish abundance and biodiversity trends against cumulative number of upstream dams, we found that hydropower dams reduced fish biodiversity, including migratory, IUCN threatened and indicator species in the Sesan and Srepok Basins where most dams have been constructed. Meanwhile, fish biodiversity increased in the Sekong, the basin with the fewest dams. Fish fauna in the Sesan and Srepok Basins decreased from 60 and 29 species in 2007 to 42 and 25 species in 2014, respectively; while they increased from 33 in 2007 to 56 species in 2014 in the Sekong Basin. This is one of the first empirical studies to show reduced diversity following dam construction and fragmentation, and increased diversity in less regulated rivers in the Mekong River. Our results underscore the importance of the Sekong Basin to fish biodiversity and highlight the likely significance of all remaining free-flowing sections of the Lower Mekong Basin, including the Sekong, Cambodian Mekong, and Tonle Sap Rivers to migratory and threatened fish species. To preserve biodiversity, developing alternative renewable sources of energy or re-operating existing dams to increase power generation are recommended over constructing new hydropower dams.

Restoring the Mesopotamian Rivers for Future Generations: A Practical Approach

AbstractIt is not an understatement to say that a thriving and healthy river system for the Mesopotamian region means a thriving economy for all with a productive agriculture and a sustainable manufacturing base that needs reliable water supply and cheap power. When looked at from a 30,000 feet from the ground, the Mesopotamian region began experiencing a steady decline in the health of its rivers from the 1980s with a series of unfortunate man‐made events ranging from wars to uncoordinated dam development. While there have been many analyses and historical dissection of the current water situation, one question that we all need to ask now is How can we restore the Mesopotamian rivers?

Socio-ecological challenges of hydroelectric dams among ethnic minorities in northern Laos

Globally, hydroelectric dams are increasingly considered to be a sustainable source of renewable energy. Many countries have invested in hydroelectric projects to boost the local and national economies. The findings of recent hydroelectric projects are mixed. Even though the construction of these dams has provided immediate benefits to surrounding communities, long-term negative implications of hydroelectric development have called into question the true sustainability of hydroelectric projects. These negative impacts of hydroelectric dams include the resettlement of marginalized communities, in addition to significant alterations to the local environment and economy. Taking both the positive and negative impacts of hydroelectric development into consideration, this paper examines how such hydroelectric dam development projects have led to the extreme marginalization of already vulnerable ethnic groups in Laos. Particularly, it focuses on the effects of hydroelectric dams on one of the largest ethnic groups in northern Laos, the Khmou. The findings suggest that the construction of hydroelectric dams act as a double-edged sword for the local environment, people, and economy. This study is an attempt to synthesize the existing knowledge to shed light on the negative implications that hydroelectric developments have had on ethnic minorities, particularly Khmou in northern Laos. Even though this paper has a geographical focus on northern Laos, the findings are relevant for understanding the impacts of hydroelectric dams on various historically marginalized populations in other parts of the Global South.

Sustainability Evaluation of a Concrete Gravity Dam: Life Cycle Assessment, Carbon Footprint Analysis, and Life Cycle Costing

Exploring the life cycle of infrastructures, like dams, is important for decision-makers since it allows for evaluating its overall sustainability, and identifying ways to balance the benefits and costs of dam development. In this study, the life cycle assessment (LCA) of the existing concrete gravity Pine Flat dam in the stages of construction to destruction, disposal, and recycling is investigated through ReCiPe 2016 methodology and the effect of two approaches of seismic retrofitting and non-retrofitting in the life cycle of the dam is studied. For a comprehensive understanding of the sustainability of the dam's life cycle, carbon footprint analysis (CFA) and life cycle costing (LCC) are also conducted to identify the main sources of greenhouse gas (GHG) emissions and evaluate the economic performance. These demands begin by assessing the dam’s life cycle across three distinct stages, namely, initial construction, seismic retrofitting, and decommissioning, assuming recycling 20% of demolished concrete for the last stage. The outcomes of the evaluation are then presented for four different life cycle scenarios. The findings have underscored the importance of reducing air pollution and emphasize that human health is the most significant environmental concern as compared to the ecosystem and resource indicators. The concrete recycling considered during the decommissioning stage led to a 32% reduction in pollution caused by the dam disposal process. Additionally, the effect of retrofitting dams in decreasing environmental impact indicators such as carbon footprint and human health has been considered when compared to dam disposal. The economic and environmental costs of retrofitting Pine Flat dam were obtained about half of the equivalent expenses for its disposal and recycling stage.

Impoverishment Persistence in Hydropower Dam-Induced Resettled Communities: A Sociological Investigation on Livelihood and Food Security in Vietnam

The widespread development of hydropower dams has led to involuntary displacement, which has become a significant global issue. In Vietnam, around 70,000 households were displaced in 2020, causing uncertainty and social disruption. The aim of this study is to analyze the effects of resettlement on the livelihood and food security of displaced households, explore the underlying challenges and causes of these effects, and recommend policy implications for sustainable livelihood development and poverty alleviation. This study conducted a decade-long sociological examination of three displaced communities in Thua Thien Hue province, Vietnam. Our research reveals that resettled households are unable to regain their former standard of living due to the loss of cultivated land and restricted access to public property, which exacerbates food insecurity. Unemployment, illiteracy, and low income further perpetuate poverty. These findings highlight the deficiencies in current policies and planning approaches and call for implementing socially responsible resettlement processes guided by principles of equity. Addressing the inequalities arising from displacement and enabling affected communities to participate in growth is economically justified and morally imperative.

Spatial and temporal morphological changes in the lower Mekong River under the influence of sediment load reduction in the upstream

Due to the natural and anthropogenic activities, especially the rapid development of hydropower dams in the upper Langcang Mekong, the sediment flux in the lower Mekong has declined alarmingly. This factor is one of the main reasons causing the river morphological changes in the lower Mekong. In this study, we used the MIKE 21 model to simulate the spatial and temporal morphological changes of the Hau River crossing Tra Vinh and Soc Trang, Hau Giang, and a part of Can Tho and Vinh Long provinces of Vietnam, considering the impact of sediment load decrease from the upper boundary. The models were calibrated and validated using the data of the year 2017, and the scenario of a fifty percent reduction of sediment flux from upstream was considered. The results show that the erosion occurrence in the flood season is more significant compared to that in the dry season. However, the spatial distribution tendency of erosion and accretion was similar in the two seasons. Under the impact of reduced sediment load entering the investigated region, the spatial distributions of erosion and accretion locations were estimated to significantly change during dry and flood seasons. However, the riverbed change level changed apparently. The change is more considerable in the flood season; especially, the erosion was estimated to be more severe in all zone of the study area. The erosion level was estimated to increase up to 0.15m in the flood season in zone 1 compared to that under the historical condition. The accretion level increases up to 0.09m in zone 2 and 0.07m in zone 3 under flood season. The erosion level increases up to approximately 0.1m over six months of the dry season and flood season. The results of the study can contribute to the future management strategy for the local governments in particular and for the whole Mekong region in general.

Hydropower Dam Development and Fish Biodiversity in the Mekong River Basin: A Review

Over the last few decades, considerable concern has been expressed about the threat of Mekong River Basin hydropower dams to a range of important freshwater riverine fisheries, particularly for fish that seasonally migrate long distances. However, much less attention has been given to the threat of hydropower dams to fish biodiversity in the high-diversity Mekong River Basin, the focus of this paper. Through reviewing the existing state of knowledge regarding Mekong River Basin fish biodiversity, and threats to it, we argue that even though no species are definitively known to have been extirpated from the Mekong River Basin to date, hydropower dam development and various other developments nevertheless pose a serious threat to fish biodiversity. Indeed, dams typically significantly block fish migrations and fish larvae distribution, cause river fragmentation, fundamentally alter river hydrology, and change water quality, all factors that have the potential to intersect with each other and lead to significant species extirpation and extinction, or in some cases, functional extinction, when a small population remains but the important larger population is lost permanently. The circumstances are further exacerbated by the lag time between impact and when that impact becomes evident, cumulative impacts, a lack of consistent data collection, including the collection of base-line data, and insufficient post-project research related to biodiversity. We contend that much more could and should be done to ensure that the Mekong River basin’s exceptional fish biodiversity is not variously diminished and destroyed during the coming years.

Stocking to offset negative effects of dam construction and balance the ecosystem

AbstractAn ecohydraulic model system was developed to evaluate the effects of the Da‐Wei dam construction and possible fish restoration strategies. The ecohydraulic model system consists of a hydrodynamic model, a hydromorphology model, a habitat model, and the logistic and matrix population models. The effects of dam construction and fish stocking strategy on fish habitat and population status were studied in the Jiao‐Mu River, providing the modeled ecological status of Schizothorax prenanti and Schizothorax plagiostomus heckel populations within the river segment. The two fish species richness, fish age structures, and fish density distributions were predicted. Based on the fish number prediction, the optimal number of fish to stock was evaluated with the population models, and an optimal fish stocking proposition was worked out. The results indicated that the two fish species habitat quality and fish richness would decrease due to the hydropower dam construction, and the fish stocking strategy could make up the fish species ecological status. The findings could facilitate the quantity and quality assessment of a dam development plan and increase the success rate of fish restoration.

Scales of justice. Large dams and water rights in the Tigris–Euphrates basin

Abstract The paper explores the politics of scale associated with the top-down planning of large hydraulic infrastructures in the Tigris–Euphrates basin. Against the backdrop of a worsening water crisis and the lack of cooperation between riparian countries, dams and reservoirs across the transboundary river system are sites of contestation between competing claims over dwindling and disputed resources. Drawing on post-structuralist insights from human geography on the politics of scale and the literature on megaprojects, it is argued here that hydraulic infrastructures are materially and discursively implicated in the construction of waterscapes at different scales to sustain broader political imaginaries. Based on ethnographic fieldwork and with a focus on the autonomous Region of Kurdistan in Iraq, the analysis juxtaposes the narratives deployed by state- and non-state actors to support or counter the development of additional dams. While, on the one hand, the Kurdistan Regional Government portrays hydraulic infrastructures as a vital source of security and well-being within the overarching nationalist narrative of Kurdish self-determination, on the other hand, transnational civil society groups under the umbrella of the Save the Tigris and Iraqi Marshes Campaign have mobilized against the adverse impact of megaprojects and appealed to the common Mesopotamian heritage in order to de-escalate political tensions within the transboundary river basin. In both cases, hydraulic infrastructures provide a framework for political action to secure recognition of rights and assert the appropriate scale of governance. Furthermore, bottom-up resistance is accompanied by the promotion of a participatory and inclusive approach to shared waters. From this perspective, the spatial politics of megaprojects intersect with issues of identity, equity, and sustainability.

Development of a biotic integrity index based on long-term fish assemblage changes after dam construction in China

Multi-metric indicators based on fish assemblages have been widely applied to assess aquatic ecosystem biotic integrity. However, many of these were not detailed or standardized in metrics selection and reference status for a reservoir ecosystem under the long-term effects of hydro-electrical dam development. This makes it very difficult to determine the reference status and metrics because fish assemblages have been affected by human activities such as large reservoir operations. Based on long-term fish assemblage data, there were significant differences in fish composition between backwater and reservoir areas 10 years after the Three Gorges Reservoir (TGR) formation in China. We conducted this study to develop a new fish index of biotic integrity (IBI) to evaluate a large river reservoir ecosystem based on long-term monitoring data by establishing subregional habitat reference and selecting sensitive and concise metrics. In the Three Gorges Reservoir, we found that: 1) dynamic change is an important feature of fish assemblages in a relatively dynamic state after a decade of intensive disturbance caused by reservoir operations; 2) reference conditions for the reservoir evaluation should be selected in different stages for two different ecological habitats (lotic backwater and lentic reservoir reaches); 3) two core metrics and five sensitive metrics were selected to reflect fish assemblage degradation based on long term observations; and 4) overall fish biological integrity is generally “fair-poor,” in the reservoir area it is “fair” and “poor,” and in the reservoir lotic backwater it is “fair.” The long-term effects of large canyon reservoirs on biological integrity require long-term observation, and reasonable recovery targets should be set at different stages in reservoir management. In this study, a new biological integrity index was developed to screen and evaluate the ecological status of a semi-artificial reservoir ecosystem. Our results support reservoir biologically integrated management and green sustainable development goals.

Cultural Resource Management: A Collaborative Primer for Archaeologists

Cultural Resource Management: A Collaborative Primer for Archaeologists