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In this study, the influence of the South-to-North Water Diversion Project (SNWDP), China on meteorological parameters, including precipitable water vapor (PWV), precipitation, and three types of soil moisture, are first analyzed from 1994 to 2023 in the middle route flowing area. Three statistical methods based on the Generalized additive model (GAM), Theil-Sen trend analysis (TSTA), and Mann-Kendall significance test (MKST) are adopted to investigate the variation of these parameters. GAM and TSTA are mainly used to evaluate the variation trend from the perspective of temporal and spatial, respectively. MKST is used to assess whether the variation is significant. Through the comparative analysis before and after the opening of the SNWDP, as well as the overall period of analysis, three important findings can be concluded: (1) Before the opening of SNWDP, all of the PWV, precipitation, and soil moisture had continuously declined in the past 20 years from 1994 to 2014. The average decrease of PWV and precipitation is approximately 0.04 mm and 18.19 mm, respectively. Moreover, regarding the three types of soil moisture, the average volumetric water content decreased by 0.17% in the 0–7 cm surface layer, 0.21% in the 8–28 cm intermediate layer, and 0.29% in the 29–100 cm deep layer. (2) After the SNWDP was put into operation, the decreasing trend of these parameters is obviously mitigated from 2015 to 2023. Concretely, the average increase of PWV is approximately 0.09 mm from 2015 to 2023, even though there was an extreme drought event in 2019. (3) Based on the results of MKST, it can be found that PWV shows a significant increase at 80% and above confidence levels in 41.73% of the regions from 1994 to 2023. However, it should be noted that although the SNWDP significantly improves precipitation and soil moisture, neither has recovered to the level around 1994. [ABSTRACT FROM AUTHOR]

Slope deformation is an important indicator for landslide warning. Due to the influence of internal and external factors, slope deformation of deep excavated expansive soil canals exhibits significant spatiotemporal heterogeneity. In this study, a comprehensive method for analyzing the spatiotemporal characteristics of deformation and determining potential sliding surfaces was developed. The soft dynamic time warping algorithm was used to measure the similarity of slope displacements at different depths. The hierarchical clustering method was applied to cluster measuring points, thus distinguishing the similarity and heterogeneity of displacements of measuring points. The weighted multiscale local outlier factor algorithm was employed to identify measuring points with sudden displacement changes in order to determine the potential sliding surface. A case study was conducted on a deep excavated expansive soil canal slope in the middle route of the South to North Water Diversion Project in China. The slope experienced significant deformation and had exceeded the allowable deformation value after 3 years of operation. Both the fluctuation depth of the groundwater level and the deformation depth exceeded 10 m. All of the clustering numbers of the measuring points of the inclinometer tubes were 3, but the depths of Cluster 1 were different. The potential sliding surface was a polyline, with a depth of greater than 10 m. It can be concluded that the potential failure mode is a deep landslide. The studied case demonstrates the effectiveness and reliability of the proposed method, which can provide a reference for operation management of similar projects. [ABSTRACT FROM AUTHOR]

The construction of the national water network optimizes water resource allocation but also causes a redistribution of pollutants due to water quality differences, posing urgent challenges for water pollution management. Taking the South-to-North Water Diversion Project and Yangtze-to-Hanjiang River Water Diversion Project (YHRWDP) as an example and considering the pressure brought by the redistribution of pollutants to the polluting enterprises (PE) and water diversion enterprises (WDE) situated in areas where pollution is aggravated, a differential game model of pollution control among the central government, water-supply area (WSA), PE and WDE is constructed based on the cost-sharing mechanism. The results show that: (1) The pressure coefficient has an apparent negative correlation with the effort level of the affected subject. (2) An increase in the amount of pollution elimination per unit of pollution control effort of WSA and PE will lead to their own investment in more efforts to improve the ecology of the basin, thus benefiting all participants in the system. (3) The cost-sharing rate of the central government on the WSA of the YHRWDP, the PE, and the WDE is influenced by several factors, which shows a stable monotonically increasing or decreasing relation. The results are an useful supplement to the research on natural river pollution control, and can also provide a reference for designing pollution control mechanisms of national water network. [ABSTRACT FROM AUTHOR]

Groundwater restoration is increasingly common to mitigate groundwater overexploitation, which proves effective in resolving urban water scarcity and regional unsustainable development. China's South-to-North Water Diversion Project is one of the largest water transfer projects to restore groundwater and resolve water shortage in Beijing. However, how the rapidly restored groundwater of this magnitude changes regional seismic stability is largely unknown. Here, we explore the relation between elevated groundwater table and seismic ground liquefaction based on the case of Beijing under the impact of the South-to-North Water Diversion Project. We collect groundwater table depth records and use them to drive three-dimensional geotechnical models that generate ground liquefaction hazard maps. We find a remarkable increase in coverage and severity of liquefaction due to groundwater table rise. Infrastructures built during the rapid urbanization process are often under low groundwater table and thus illy prepared for this increased seismic risk. These findings highlight the necessity to consider the seismic consequence of large-scale groundwater restoration projects. The authors find that groundwater table recovery leads to a remarkable increase in seismic liquefaction risk in Beijing. The findings highlight the necessity to consider the influence of rapid groundwater restoration on seismic safety in megacities. [ABSTRACT FROM AUTHOR]

The Middle Route of the South to North Water Diversion Project (MRP) and its water source, the Danjiangkou Reservoir (DJK), play a pivotal role in mitigating the chronic water scarcity challenges faced by northern China. Eukaryotic plankton are widespread in aquatic ecosystems, which are crucial for the water quality stability of DJK and MRP, yet comparative studies on their contemporaneous dynamics and assembly processes are scarce. In this study, amplicon sequencing was used to investigate the eukaryotic plankton communities. The results revealed that the similarity in community composition of DJK is significantly higher than that of MRP, exhibiting distance-decay patterns. Environmental heterogeneity exhibits significant differences between DJK and MRP, and it significantly influences community composition and alpha diversity. Additionally, the assembly processes of eukaryotic plankton in both DJK and MRP are predominantly influenced by stochastic processes. However, in comparison to DJK, deterministic processes have a more pronounced impact on MRP, accounting for 39.29% and 1.82%, respectively. The variations in total nitrogen (TN), chlorophy IIa (Chl.a), and conductivity (Spc) have led to a transition in the assembly of eukaryotic phytoplankton communities in MRP from a stochastic process to a deterministic process. This study extends insights into the dynamics and assembly processes of eukaryotic plankton communities in the large, engineered drinking water diversion project and its water source, which is also useful for the management and regulation of the DJK and MRP. [ABSTRACT FROM AUTHOR]

Simple Summary: From the initial outbreak of Formosan ferret-badger (FFB) rabies in Taiwain in 2013 until December 2022, the epizootic had remained continuously limited on the south side of the Daan River, which was considered as a natural barrier preventing the reservoir FFBs from crossing over. However, in 2023, cases of FFB rabies appeared in Miaoli County, located north of the Daan River. Several factors may have contributed to this crossing, including (1) decreased rainfall in the Daan River catchment in recent years, reducing water sources in FFB habitats and forcing FFBs to seek forage outside their mountain habitats; (2) the construction of the Shilin Weir in the upstream of Daan River, possibly leading to drought during the dry seasons, allowing reservoir FFBs to cross from the south side into Miaoli County; and (3) thehe unusually high incidence of FFB roadkills s during the 2023 rainy season, indicating an overall increase in FFB activity. These pieces of evidence supported the speculation that FFBs crossed the Daan River, introducing FFB rabies into Miaoli County. The first detection of Formosan ferret-badger (FFB) rabies on the main island of Taiwan occurred in July 2013. National surveillance reports indicated that prior to 2023, rabies outbreaks were limited to the southern region of the Daan River, which was considered a natural barrier preventing the spread northwards. However, in 2023, four new cases of rabid FFBs emerged in Miaoli County, located north of the Daan River, suggesting that the epizootic had crossed the river. Several factors may have contributed to the ability of reservoir FFBs to cross over the Daan River. Firstly, there was a decrease in rainfall in the upstream area of the Daan River in 2023. Secondly, the construction of the Shilin Weir by the Taiwan Power Company in the upstream area of the Daan River aimed to prioritize water diversion for hydropower generation while ensuring domestic water supply for Miaoli County and Taichung City. Lastly, there was an unusual increase in the number of roadkill FFBs during the rainy season of 2023. The decreased rainfall in FFB habitats in the mountains and the near-dry condition of the upstream Daan River caused by the Shilin Weir in 2023, allowing FFBs to easily cross the Daan River into Miaoli County. The evidence of unusually increased FFB activity in 2023 supports the speculation that FFBs crossed the Daan River, introducing FFB rabies into Miaoli County. [ABSTRACT FROM AUTHOR]

The route of the South-to-North Water Diversion channel strides across part of the coal mine goaf in Yuzhou County, Henan Province, China, and long-term deformation due to coal seam recovery poses a threat to the safe operation of the main canal. Therefore, the study of the deformation mechanisms induced by coal seam recovery is of great significance to the canal's safe operation, as well as to deformation monitoring and to the development of early warnings. The geologic model was established based on the geological engineering conditions of the Yuzhou Gongmao mining area, spanning the main canal of the South-to-North Water Diversion Project; then, the physical model test was carried out according to similar theories. The deformation characteristics of the rock overlay and the channel above the goaf were analyzed, and failure criteria for overburdened rock and the channel were proposed. The results showed that horizontal fissures were gradually observed in the overlying rock as the coal mining progressed, extending and widening. When the goaf was excavated to 76 cm, the overlying rock body suddenly collapsed as a whole, and the channel collapsed and was destroyed. During the formation of the goaf, there was a critical span ratio (R): When the height-to-span ratio was greater than 0.039, the collapse of overlying rock occurred only within a certain range above the goaf. When the height-to-span ratio was less than 0.039, the overlying rock body collapsed in a wide area, and the soil on both sides of the channel collapsed to the center of the channel, presenting a "V" glyph collapse. The sediment in the center of the channel measured 22 mm, and there were multiple tensile cracks on both sides of the embankment, with a width of 5–10 mm. The vertical deformation of the channel went through three stages, namely, the initial deformation stage, the deceleration deformation stage, and the stability stage. This study can provide scientific guidance for early warnings of channel deformation and safe operation across the goaf. [ABSTRACT FROM AUTHOR]

The development and maturation of TBM (tunnel boring machine) technology have significantly improved the accuracy and richness of excavation data, driving advancements in intelligent tunneling research. However, challenges remain in managing data noise and parameter coupling, limiting the interpretability of traditional machine learning models regarding TBM parameter relationships. This study proposes a cutterhead rotation speed prediction model based on dimensional analysis. By utilizing boxplot methods and low-pass filtering techniques, excavation data were preprocessed to select appropriate operational and mechanical parameters. A dimensionless model was established and integrated with elastic net regression to quantify parameters. Using TBM cluster data from a water diversion tunnel project in Xinjiang, the accuracy and generalizability of the model were validated. Results indicate that the proposed model achieves high prediction accuracy, effectively capturing trends in cutterhead rotation speed while demonstrating strong generalizability. [ABSTRACT FROM AUTHOR]

Ecological flow is a crucial determinant of river ecosystem well-being and aquatic ecosystem stability. Large- and medium-sized reservoirs, with flood prevention, irrigation, and power generation functions, necessitate a scientifically devised ecological flow release plan for river ecosystem conservation and water quality amelioration. This study centered on three reservoirs in the Jiaojiang River Basin of Zhejiang Province, China. Using measured outflow data, the hydrological approach was initially adopted to calculate individual reservoir ecological flows. Subsequently, the entropy weight method was employed to ascertain the most suitable ecological flow. Ecological flow grade thresholds were then established to formulate the optimal release scheme. The outcomes demonstrated that the average ecological flows of Xia'an, Lishimen, and Longxi reservoirs were 1.90 m3/s, 1.95 m3/s, and 0.42 m3/s, respectively. The multi-year average ecological flow assurance rates were 62.53%, 77.72%, and 56.94%, successively. The entropy weighted downstream optimal ecological flows were 2.10 m3/s, 2.28 m3/s, and 0.44 m3/s. During periods when the monthly ecological flow assurance rate was below 60%, the three reservoirs implemented schemes of installing ecological siphons, renovating water diversion systems, and using post-dam ecological units, respectively. [ABSTRACT FROM AUTHOR]

Since the 1980s, Xuanwu Lake in Nanjing, China, has experienced eutrophication. Some restoration measures were implemented in Xuanwu Lake to control water eutrophication, including sediment dredging, algal bloom control through clay flocculation, and the promotion of aquatic macrophyte growth. This study aims to compare the water quality improvement levels achieved by various restoration measures. The water quality parameters, including dissolved oxygen concentration, total nitrogen, ammonia nitrogen, total phosphorus, permanganate index, etc., were monitored before and after implementing these measures. The results showed that the sediment was not the primary pollution source of the water body, the dredging did not change the nutrient contents in the lake significantly, and the heavy metal content in the sediment also did not decrease significantly. The water quality improved with increased water diversion, but improved less when it exceeded a certain level. Considering the comprehensive water quality and the cost of water diversion, it is recommended to divert 18 × 104 m3 of water per day. Clay flocculation effectively inhibited cyanobacterial blooms within a short time, improved water quality, and promoted the restoration of the Potamogeton crispus population. Aquatic population restoration is a sustainable and effective approach for Xuanwu Lake and controlling water eutrophication, water quality was improved distinctly during the growing period of the P. crispus population, compared to when aquatic vegetation was minimal. Partial harvesting of hygrophytes at the appropriate time will improve water quality. Therefore, in the management of eutrophic lakes, the method of dredging sediment should be carefully selected because it does not have a significant impact on improving water quality. Water diversion can improve water quality, but the amount of water diverted should be controlled at an appropriate level. Clay flocculation is an effective method for controlling algal blooms in emergency situations. The restoration of aquatic macrophytes is an effective way to maintain the health of aquatic ecosystems, and partial harvesting at the appropriate time will significantly improve water quality. [ABSTRACT FROM AUTHOR]

The classification of a hydropower scheme as run-of-the-river (or run-of-river; ROR) evokes an image of a low-impact installation; however, examination of eight case studies worldwide shows that substantial negative societal and ecological impacts are tied to them, albeit in somewhat different ways. We conclude that ROR dams not only potentially displace communities, disrupt livelihoods, and degrade environments in surrounding areas, but they also divert water from areas of need, impact aquatic ecology through habitat destruction and disruption of fish migrations, emit non-trivial amounts of greenhouse gases over the lifespan of the project, and disrupt streamflow in downstream river sections. While these negative impacts vary on a case-by-case basis, medium and large ROR dams consistently have multiple and cumulative impacts, even when not having appreciable reservoirs. We contend that many impactful dams do not qualify as low-impact ROR projects, despite being defined as such. Such mislabeling is facilitated in part by the ambiguous definition of the term, which risks the ROR concept being used by proponents of impactful structures to downplay their negative effects and thus mislead the public or gain status, including within the Clean Development Mechanism in relation to mitigating climate change. [ABSTRACT FROM AUTHOR]

Water pipelines in water diversion projects can leak, leading to soil deformation and ground subsidence, necessitating research into soil deformation monitoring technology. This study conducted model tests to monitor soil deformation around leaking buried water pipelines using distributed fiber optic strain sensing (DFOSS) technology based on optical frequency domain reflectometry (OFDR). By arranging strain measurement fibers in a pipe–soil model, we investigated how leak location, leak size, pipe burial depth, and water flow velocity affect soil strain field monitoring results. The results showed that pipeline leakage creates a "saddle-shaped" spatial distribution of soil strain above the pipeline, effectively indicating ground subsidence locations. When only one survey line is arranged, it is preferable to place the optical fiber directly above the pipeline. Surface monitoring fibers primarily detected tensile strain, with more pronounced peak values observed under conditions of larger leak size, higher flow velocity, shallow burial depth, and top-pipe leakage location. Monitoring fibers below the pipeline showed mainly unimodal distribution, with peak strain coinciding with the leak location. The sequential timing of strain changes at different fiber positions enabled the determination of soil seepage direction. This study demonstrates that DFOSS technology can provide important support for the early warning of such geological disasters. [ABSTRACT FROM AUTHOR]

This investigation and critical revision of the ichthyofauna of Tajikistan is the result of two nationwide surveys completed by the authors in 2017 and 2019 combined with an analytical examination of previous studies. The ichthyofauna of Tajikistan includes 60 species, of which 44 are native and 15 are nonnative, while one species (Cyprinus carpio) is represented by populations of native and alien origin. Seven species recorded in neighboring countries could potentially be found in Tajikistan, 12 introduced species are nonnaturalized, two were erroneously identified as belonging to the ichthyofauna of Tajikistan, and two are extinct. The current fish fauna is represented by eight orders (Acipenseriformes, Cypriniformes, Cyprinodontiformes, Gobiiformes, Perciformes, Salmoniformes, Siluriformes, and Synbranchiformes) and 18 families (Acipenseridae, Acheilognathidae, Channidae, Cobitidae, Cottidae, Cyprinidae, Esocidae, Gobiidae, Gobionidae, Leuciscidae, Nemacheilidae, Odontobutidae, Percidae, Poeciliidae, Salmonidae, Siluridae, Sisoridae, and Xenocyprididae), of which the largest number of species belong to Leuciscidae (14 species), Nemacheilidae (13 species), and Cyprinidae (9 species). Significant changes in the fish fauna occurred in the 20th century due to anthropogenic factors and climate change. Water diversion for irrigation and construction of canals and reservoirs led to changes in the hydrological regime, which, combined with illegal fishing and overharvesting dramatically affected the abundance of at least eight species and led to the extinction of two, Acipenser nudiventris and Pseudoscaphirhynchus fedtschenkoi. Massive introductions of commercial fish species in the 20th century led to an increase in the alien fauna to 16 species. [ABSTRACT FROM AUTHOR]

The ball-pitching plugging-selection profile control technology represents an effective and low-cost means of adjusting the profile of waterflooding well. The technology primarily utilizes polymer balls to plug the perforations, thereby achieving the effect of fine profile control. This paper aims to elucidate the migration and plugging laws of plugging-selection balls in wellbore and perforation plugging processes. Accordingly, the effects of flow rate of waterflooding, and density, diameter, quantity of plugging-selection balls on the plugging effect of perforation were investigated through numerical simulation and experiments. This revealed the movement laws of waterflooding and plugging-selection balls during ball-pitching process. The findings of the research indicated that the diversion effect mainly was primarily observed in the layers with strong water absorption capacity, and the migration process of plugging-selection balls demonstrated both single and multiple plugging effects, which were influenced by the parameters of waterflooding and plugging-selection balls. The well plugging effect could be achieved when the flow rate of waterflooding was 2 m3/h, the density of ball and waterflooding was similar, the plugging-selection ball diameter was 10 mm, and the ball-perforation number ratio exceeded 1.0. The application of typical wells indicated that, the ball-pitching plugging-selection profile control technology could enhance oil production, finely control reservoir utilization, and enhance economic benefits. [ABSTRACT FROM AUTHOR]

Interbasin water transfer is a globally employed and significant strategy to address water scarcity, conflicts, and achieve specific Sustainable Development Goals (SDGs). The issue of water loss during the process of water transfer has garnered increasing attention with the construction of water diversion projects. This study aims to focus on the primary factors influencing the water loss in the Middle Route of the South-to-North Water Diversion Project (MR-SNWDP) from a humanistic perspective based on innovative comprehensive evaluation method of coupling qualitative and quantitative analysis. Additionally, the potential human factors are derived from a relatively large and objective indicator set rather than a limited set of manually selected. The results show that the number of optimal human factor (21, 20, 22, 22 and 21 for the main pipe and canal of MR-SNWDP, Beijing City, Tianjin City, Hebei Province, and Henan Province, respectively) is condensed by more than 65%, which has been categorized into social economy, science and technology culture, production and living, and management institution. The driving force behind these indicators varies greatly in different regions due to the difference of water resources endowment and utilization. Furthermore, the social economy factor exerts a negative influence on the typical SDGs (indicator 6.4.2 and indicator 6.5.2), and it has the greatest driving force among these human factors. Various potential humanistic strategies are proposed across these categories to enhance the efficiency of water transfer. Although this innovative method represents an initial application of optimizing human factor, it can also be extended for other complex decision-making. [ABSTRACT FROM AUTHOR]

With the extensive construction of pumped storage power stations, understanding the evolution, propagation laws, and factors influencing downstream dam-break floods is essential for effective disaster prevention and mitigation. This paper examines a specific pumped storage power station and develops a numerical model that integrates the dynamics of dam-break floods with the evolution of breach formation. Four dam-break scenarios were created to simulate various situations. The findings indicate that: First, peak flows increase in certain river sections due to changes in river geometry and water diversion/confluence during the evolution of dam-break floods. Second, the analysis shows that damage from a single reservoir's dam break is less severe than that from two reservoirs. Damage varies with distance from the dam: upstream areas experience relatively minor combined dam damage, while instantaneous full dam break damage is greatest; downstream, instantaneous full dam break damage is less harmful than combined dam breaks, which are the most damaging. These variations are attributed to morphological differences and disparities in total water volume under different conditions during the dam-break flood process. This study provides a scientific basis for responding to dam-break floods and conducting flood relief efforts. [ABSTRACT FROM AUTHOR]

Urbanization, driven by socio-economic development, has significantly impacted river ecosystems, particularly in plain city regions, leading to disruptions in river network structure and function. These changes have exacerbated hydrological fluctuations and ecological degradation. This study focuses on the central urban area of Changzhou using a MIKE11 model to assess the effects of four hydrological connectivity strategies—water diversion scheduling, river connectivity, river dredging, and sluice connectivity—across 13 different scenarios. The results show that water diversion, river dredging, and sluice connectivity scenarios provide the greatest improvements in water environmental capacity, with maximum increases of 54.76%, 41.97%, and 25.62%, respectively. The spatial distribution of improvements reveals significant regional variation, with some areas, particularly in Tianning and Zhonglou districts, experiencing declines in environmental capacity under sluice diversion and river-connectivity scenarios. In addition, the Lao Zaogang River is identified as crucial for improving the overall water quality in the network. Based on a multi-objective evaluation, combining environmental and economic factors, the study recommends optimizing water diversion scheduling at sluices (Weicun, Zaogang, and Xiaohe) with flow rates between 20–40 m3/s, enhancing connectivity at key river hubs, and focusing management efforts on the Lao Zaogang and Xinmeng rivers to strengthen hydrological and water quality linkages within the network. [ABSTRACT FROM AUTHOR]

Taking the tributary confluence at the Jianghuai communication section and Caizi Lake section of the Yangtze-to- Huaihe River Water Diversion Project as examples, in view of the complex navigable flow conditions existing in the typical intersection sections, the transverse flow velocity distribution in the intersection water area under the selected confluence condition was compared by numerical simulation method, and the cross-aspect ratio of the river channel was analyzed, so as to evaluate the safety of the navigable flow conditions of the section. The results show that the maximum cross-flow area is located near the downstream of the confluence mouth, and the cross-flow value decreases radially to the opposite bank, where the cross-aspect ratio is the largest, so it should be regarded as the most dangerous area for navigation. With the increase of the confluence ratio and the tributary confluence angle, the cross-flow value and cross-aspect ratio of the confluence increase accordingly. When the tributary confluence angle is 30°, the confluence ratio is 0.7 and the tributary confluence angle is 90°, and the confluence ratio is 0.2, the navigation environment of the channel is relatively safe, and there are different degrees of navigation risks in other working conditions. The research results can provide some technical support for the navigation safety evaluation of other confluence water areas in the Jianghuai communication section and the Caizi Lake section. [ABSTRACT FROM AUTHOR]

Simple Summary: Hongze Lake, a key storage lake in China's South-to-North Water Diversion project, experiences off-seasonal water level regulation that disrupts native fish and others. This study explored the trophic dynamics of three fish species—Parabramis pekinensis, Carassius auratus, and Toxabramis swinhonis—using stable isotope analysis during high-, mid-, and low-water periods. Results showed that all three fish species generally occupied similar mid-level trophic positions across different water periods. The SEAc values of P. pekinensis and T. swinhonis were highest during high-water periods and lowest during low-water periods, whereas C. auratus exhibited the opposite trend. These findings suggest that P. pekinensis and T. swinhonis function as optimal foragers, while C. auratus adopts a generalist strategy, consistent with classical competition theory. Niche overlap analysis demonstrated that dynamic resource partitioning during high-water periods and resource sharing during low-water periods promote the coexistence of these species. This coexistence strategy is further influenced by shifts in dietary composition, as although POM was the main dietary component, its contribution decreased over time as SOM and macrophytes became increasingly significant, highlighting the adaptability of these species to fluctuating environments. This study emphasizes the role of water level fluctuations in shaping interspecific interactions, providing insights into coexistence mechanisms of euryphagous fish species and ecological dynamics in Hongze Lake. Off-seasonal water level regulations disrupt the biological traits and phenological rhythms of native fish species, yet their impacts on interspecific trophic interactions remain understudied. This study employed stable isotope analysis to assess the trophic dynamics of three fish species (Parabramis pekinensis, Carassius auratus, and Toxabramis swinhonis) across different water periods in Hongze Lake. The findings revealed that all three species occupied similar mid-level trophic positions, with no significant difference among water periods (p > 0.05). During high-water periods, P. pekinensis and T. swinhonis exploited broader niches, while C. auratus relied on a narrower diet. In contrast, during low-water periods, C. auratus expanded its niche, while P. pekinensis and T. swinhonis reduced their isotopic niche widths. Niche overlap analysis showed minimal trophic overlap among the three species during high-water periods, with increased overlap during low-water periods, except for the highest overlap between C. auratus and T. swinhonis during mid-water periods. This variation in niche overlap aligns with shifts in dietary reliance, as POM was the predominant dietary component for all three species, but its contribution varied significantly across different water periods. These findings indicated that adaptive trophic niche facilitated the coexistence of these fish species, while off-seasonal water level regulation may intensify interspecific competition. These insights are essential for refining water management policies and developing sustainable fishery management strategies of Hongze Lake and other water-level-regulated systems. [ABSTRACT FROM AUTHOR]

Water diversion aqueducts are highly susceptible to freezing and blockage at low temperatures in winter, particularly in the cold and arid regions of northern China. There are also significant declines in the water conveyance capacity and structural performance. A great threat has then been posed to the long-term safe operation of water diversion projects in these regions. Therefore, it is crucial to the patterns of winter water temperature and the mechanisms of icing evolution in aqueducts. However, it is still lacking in the winter operational characteristics of aqueducts. This study aims to investigate the spatiotemporal variations of water temperature and icing behavior under the influence of multiple coupled factors. A three-dimensional coupled numerical model was developed for the non-isothermal flow heat transfer in a closed aqueduct. Some parameters were then considered, including air temperature (Ta), flow velocity (u), inlet water temperature (T0), solar radiation, and wind speed. The characteristic parameters were selected as the temperature drop value (ΔT) and temperature drop rate (Δfu) of the water flow in the aqueduct. A systematic analysis was implemented to explore the temporal and spatial variation patterns of winter water temperature. Additionally, a predictive model was also established for the water temperature and freezing points. The average water temperature was then calculated at the outlet section of the aqueduct under various conditions. The icing locations of the water flow were predicted under specific temperature scenarios. A two-dimensional transient icing model was established to consider the effect of the ice-water phase transition on heat transfer in the water flow in an aqueduct. The icing evolution was also obtained in the aqueduct water flow. The correctness of the model was verified to compare the indoor test data with the simulation. The results show that there was a decrease in the water temperature of the aqueduct over time in winter, especially with the increasing water delivery length. Along the length of the aqueduct, the temperature drops of water flow exhibited an overall trend of rapid decline followed by a slower reduction. The ΔT value decreased with the increasing u under certain meteorological conditions, as T0 rose. While there was an increase. The primary influencing factor on water temperature was the flow velocity u, with the largest temperature drop rate in the range of 0-1m/s. The temperature drops near the solid walls of the aqueduct were approximately 2 to 4 times greater than that at the center of the cross-section. Solar radiation caused a greater decrease in the water flow temperature near the aqueduct wall at night than during the day. In contrast, the water temperature at the center of the aqueduct cross-section was less affected by solar radiation. According to the water flow freezing in aqueducts, the release of latent heat during condensation shared a compensatory effect on the water temperature. The bank ice width was used as a quantitative indicator of icing. The amount of ice formation increased over time. There was a shorter critical length for the water flow near the shaded side wall of the aqueduct to reach the freezing point. The ice formation on the shady side was approximately three times that on the sunny side. This finding can also provide a strong reference for the safe operation of aqueducts at low temperatures in winter. [ABSTRACT FROM AUTHOR]

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Bulb tubular pumps have been widely used in hydraulic engineering because of their compact structure, easy maintenance, high adaptability, and other characteristics. In this paper, the performance optimization of the bulb tubular pump in the South-to-North water diversion project is studied, as well as the influence of the design of the rear guide vane structure on the hydraulic efficiency of the pump. This study takes a certain type of bulb tubular pump as its research object, optimizing the rear guide vane. Firstly, the accuracy of the numerical simulation method is verified using grid convergence analysis and model experimentation. The orthogonal experimental design method is used to optimize the design, and the range analysis results show that the blade wrap angle has the most significant influence on the hydraulic efficiency and head. Finally, the optimization results under a 0° impeller setting angle were verified by numerical analysis, and the hydraulic efficiency of the optimized pump was increased by 0.7%, 0.88%, and 1.1% under low flow, design flow, and high flow, respectively. By introducing entropy generation theory for inflow analysis, the reduction in energy loss in the pump is proven, thus verifying the effectiveness of the optimization. Through the optimization, the separation fluid phenomenon on the guide vane surface is improved, the vortex scale is reduced, and the flow field in the pump is improved to a certain extent. [ABSTRACT FROM AUTHOR]

Investigating the evolution of the pressure arch in rock masses undermining conditions is crucial for safe tunnel excavation. This study developed a mechanical model of the surrounding rock pressure arch, inspired by a domestic hydropower station's water diversion tunnel project. The characteristics of pressure arch formation and elastic energy changes during segmented excavation were examined through theoretical and numerical simulations. Results show that as excavation progresses, energy in the surrounding rock transfers, increasing energy concentration and the affected area. A symmetric pressure arch forms due to the overlying strata's gravity. The horizontal axis lengths of the pressure arch's boundaries exceed the vertical axis lengths, and the arch zone's thickness continuously increases. The mining-induced unloading effect releases elastic energy from the roof, accumulating within the pressure arch's inner boundary. When the working face reaches 30–40 m, the inner and outer boundary heights increase while the span decreases, indicating effective stress distribution and transfer by the arch structure. The arch foot, typically an area of energy concentration, determines the tunnel roof's failure characteristics along its strike. Stress concentration and elastic energy at the arch foot are critical for predicting the surrounding rock's stability in the tunnel roof. [ABSTRACT FROM AUTHOR]

Water security is essential for the development of semi-arid regions. Inter-basin water diversion projects are an important solution for guaranteeing access to water for populations in these regions. Reaching optimal water allocation in an inter-basin water diversion project is a challenge, especially in water systems that are unable to meet their demands. This study proposed a methodology for defining reservoir operation rules for inter-basin water diversion projects in semi-arid regions. The findings from taking the Apodi-Mossoró River Basin in Northeast of Brazil as a case reveal that the regulated flow of the reservoirs under constant water transfer increased in direct proportion to the transferred volume, and that it is not necessary to transfer water every year. Thus, the results show that the proposed reservoir operation policies reduce transferred volumes, thereby cutting costs, without compromising the system's water availability. This study consequently contributes to providing information in order to prepare decision-makers to implement sustainable water resource management in this region. [ABSTRACT FROM AUTHOR]

• SPM structure and its organic matter components was characterized. • SPM consists of algae, microorganisms, plant debris and inorganic minerals. • Water transfer project altered POM spatial distribution in lake area. • The P w -C2 fluorescence component was negatively correlated with inorganic nitrogen. Particulate organic matter (POM) plays a crucial role in the organic composition of lakes; however, its characteristics remain poorly understood. This study aimed to characterize the structure and composition of POM in Lake Baiyangdian using many kinds of techniques and investigate the effects of different extracted forms of POM on water quality. The suspended particulate matter in the lake had complex compositions, with its components primarily derived from aquatic plants and their detritus. The organic matter content of the suspended particulate matter was relatively high (organic carbon content 27.29–145.94 g/kg) for the sum of three extractable states (water-extracted organic matter [WEOM], humic acid, and fulvic acid) and one stable bound state (humin). Spatial distribution analysis revealed that the POM content in the water increased from west to east, which was consistent with the water flow pattern influenced by the Baiyangdian water diversion project. Fluorescence spectroscopy analysis of the WEOM showed three prominent peaks with excitation/emission wavelengths similar to those of dissolved organic matter peaks. These peaks were potentially initial products of POM conversion into dissolved organic matter. Furthermore, the intensity of the WEOM fluorescence peak (total fluorescence peak intensity) was negatively correlated with the inorganic nitrogen concentration in water (p < 0.01), while the intensity of the HA fluorescence peak showed a positive correlation with the inorganic nitrogen concentration (p < 0.01). This suggested that exogenous organic matter inputs led to the diffusion of alkaline dissolved nitrogen from sediment into water, while degradation processes of aquatic plant debris contributed to the decrease in inorganic nitrogen concentrations in the water column. These findings enhance our understanding of POM characteristics in shallow lakes and the role of POM in shallow lake ecosystems. [ABSTRACT FROM AUTHOR]

The canal is crucial for water diversion projects, but it is susceptible to frost damage. To address this, a two-layer composite geomembrane lining structure (TLCGLS) was proposed that regulates the interaction between canal lining and frozen soil. Model tests were conducted to investigate its anti-frost heave effectiveness. Considering the interaction among the lining, two-layer composite geomembranes (TLCGs), and frozen soil, a canal frost heave model with heat-water-mechanical coupling was developed. The influence of canal cross-section shapes and TLCGs arrangements on anti-frost heave performance and mechanism of TLCGLS were discussed. Results show that TLCGLS reduces uneven frost heave degree and compressive/tensile strains of the lining by 35%, 29%, and 28% respectively. During melting, it rapidly reduces frost heave, tangential deformation, and strain with minimal residual effects. TLCGLS demonstrates strong resetting ability and excellent anti-frost heave performance. It is particular suitable for arc-bottomed trapezoidal canals. However, excessive reduction in friction between TLCGs weakens arching effect of the bottom lining, increasing tensile stress and safety risks. TLCGLS with geomembrane-geotextile contact exhibits superior anti-frost heave performance, mitigating compressive stress by over 50% while meeting design requirements for tensile stress. These findings provide a theoretical basis and technical solution for mitigating frost damage in canals. • A novel two-layer composite geomembrane lining structure (TLCGLS) was proposed to mitigate canal frost damage. • Model tests are conducted to validate the anti-frost heave effectiveness of TLCGLS. • A new frost heave numerical model for canal with TLCGLS is developed. • Effect of canal shapes and two-layer composite geomembrane arrangements are discussed. • Anti-Frost heave mechanism of TLCGLS is investigated. [ABSTRACT FROM AUTHOR]

One of the most challenging aspects of manipulating the flow of fluids in subsurfaces is to control their flow direction and flow behavior. This can be especially challenging for compressible fluids, such as CO2, and for multiphase flow, including both water and carbon dioxide (CO2). This research studies the ability of two crosslinked polymers, including hydrolyzed polyacrylamide and acrylic acid/hydrolyzed polyacrylamide crosslinked polymers, to reduce the permeability of both CO2 and formation water using different salinities and permeability values and in the presence of crude oil under different injection rates. The result showed that both polymers managed to reduce the permeability of water effectively; however, their CO2 permeability-reduction potential was much lower, with the CO2 permeability reduction being less than 50% of the water reduction potential in the majority of the experiments. This was mainly due to the high flow rate of the CO2 compared to the water, which resulted in significant shearing of the crosslinked polymer. The crosslinked polymers' swelling ratios were impacted differently based on the salinity, with the maximum swelling ratio being 9.8. The HPAM polymer was negatively affected by the presence of crude oil, whereas increasing salinity improved its performance greatly. All in all, both polymers had a higher permeability reduction for the formation water compared to CO2 under all conditions. This research can help improve the applicability of CO2-enhanced oil recovery and CO2 storage in depleted oil reservoirs. The ability of the crosslinked polymers to improve CO2 storage will be a main focus of future research. [ABSTRACT FROM AUTHOR]

Desert vegetation is undergoing complex and diverse changes due to global climate change and human activities. To effectively utilize water resources and promote ecological recovery in desert areas, it is necessary to clarify the main driving mechanisms of vegetation growth in these regions. In this study, based on MODIS and Landsat 8 remote sensing image data, the vegetation changes and driving mechanisms before and after water diversion in the Kubuqi Desert from 2001 to 2020 were quantitatively analyzed using multiple linear regression, random forest, support vector machine, and deep neural network. The results show that the average NDVI in the study area has increased from 0.08 to 0.13 over the past 20 years, and the year of NDVI mutation corresponded with the lowest precipitation, which occurred in 2010. After the water diversion, under the combined influence of human and natural factors, NDVI increased steadily without any abrupt changes, indicating that water is the main limiting factor for vegetation growth. The change of NDVI also showed obvious spatial heterogeneity, among which the improvement of the southwest irrigation area was the most significant, and the area with NDVI above 0.1 showed an expanding trend, and the maximum value exceeded 0.4. This demonstrates that moderate water diversion can reduce desert areas, expand lake areas, and promote vegetation growth, yielding positive ecological effects. The integration of multiple linear regression, support vector machines, random forests, and deep neural network methods effectively reveals the driving mechanisms of NDVI and indirectly informs future water diversion intervals. Overall, these research results can provide a reliable reference for the efficient development of water diversion projects and have high application value. [ABSTRACT FROM AUTHOR]

In order to address the issue of limited excavation footage in the drilling and blasting of a water diversion tunnel with a cross-section of approximately 10 m2, which is unable to meet the demands of rapid construction, a blasting method combining long and short straight-hole cutting was proposed based on the theories of elastic mechanics, blasting craters, explosive gas and stress waves. A mechanical model was established to elucidate the parameter design method and cavity formation principle of the combined cutting. Numerical simulation and field tests were employed to analyze the rock-breaking process of combined cutting, with a view to comparing the blasting effect differences between the traditional inclined cutting method and the combined cutting method. The research results indicate that during the blasting process with combined long and short straight-hole cutting, the uncharged portion of the deep hole can serve as an empty hole during the subsequent blasting of the shallow hole. The concentration of stress at the wall of the empty hole and the superposition of reflected and incident waves serve to enhance the rock-breaking effect of the shallow hole, with the enhancement being influenced by the diameter of the hole and the distance between it and the empty hole. The preferential detonation of the shallow hole can provide a smaller resistance line and free surface distance for deep hole detonation, creating favorable conditions for rock fragmentation in deep hole blasting, making it easier for the rock in the cutting area to be thrown out and increasing the utilization rate of the blast holes. The shape of the formed cavity is a long strip-shaped cube, with its volume being influenced by the spacing between each group of deep and shallow holes. The rock mass damage is most severe in the vertical direction, while the rock mass damage at the center of the upper and lower edges is relatively weaker. In order to optimize the utilization of blasting energy, it is essential to select an appropriate spacing between each group of blast holes. In comparison to the utilization of traditional inclined cuts, the implementation of combined long and short holes has been observed to result in a greater extent of blasting footage and relatively lower explosive consumption. These research findings provide a reference point for the rapid and efficient construction of small-section tunnel engineering, as well as the design of straight-hole cut blasting with reduced consumption. [ABSTRACT FROM AUTHOR]

In recent decades, understanding how climate variability and human activities drive long-term changes in river discharge and sediment load has become a crucial field of research in fluvial geomorphology, particularly for South Asia's densely populated and environmentally sensitive regions. This study analyses spatio-temporal trends in water discharge (Qd) and sediment load (Qs) in the Krishna basin, Peninsular India's second-largest catchment. Using nearly 50 years of daily discharge, sediment concentration, and rainfall data from the Central Water Commission (CWC) and India Meteorological Department (IMD), we applied Mann–Kendall, Pettitt tests, and double mass equations to detect long-term trends, abrupt changes, and the relative influence of climate and anthropogenic effects. Results showed a notable decline in the annual discharge, with 15 of 20 stations showing decreasing trends, especially along the Bhima, Ghataprabha, and lower Krishna rivers. The annual stream flow data showed a 53% decline in the mean Qd from 26.01 × 109 m3 year−1 before 2000 to 12.32 × 109 m3 year−1 after 2000 at the terminal station. Eight of ten gauging stations showed a significant decrease (p-value < 0.05) in their annual sediment load, with a 76% reduction across the Krishna basin after its changepoint in 1983. The Pettitt test identified a statistically significant downward shift in discharge at seven stations. Double mass plots indicate that anthropogenic factors, such as large-scale reservoirs and water diversion, are the main contributors, accounting for 82.7% of sediment decline, with climatic factors contributing 17.1%. The combined trend analysis and double mass plots confirm these findings, underscoring the need for further study of human impacts on the basin's hydro-geomorphology. This study offers a clear and robust approach to quantifying the relative effects of climate and human activities, providing a versatile framework that can enhance understanding in similar studies worldwide. [ABSTRACT FROM AUTHOR]

The stability of the surrounding rock is an important engineering challenge for soft rock tunnels. Based on the FLAC3D finite difference numerical simulation software, this paper analyzes the typical area of the Fenghuang Mountain tunnel in the Chuxiong section of the Central Yunnan Water Diversion Project. Three construction methods are implemented: three-bench method, reserved core soil method, and CD method, with two excavation parameters being different lengths of the upper step and heights of the lower step. The whole excavation process of the red layer soft rock tunnel is simulated under four supporting conditions: different bolt lengths, different bolt spacings, different initial support thicknesses, and varying advanced grouting strengths. The results indicate that the CD method has a strong constraint on the vertical displacement of the surrounding rock at the arch, while the reserved core soil method has a better effect on controlling the uplift value, and the three-step method has a better constraint on the horizontal convergence of the surrounding rock at the arch waist. The increase in the distance between the upper and lower steps has a great influence on the horizontal convergence value of the tunnel, and the lower steps have a better inhibition effect on the horizontal convergence value of the surrounding rock at the tunnel arch. The increase in the lining thickness has a significant effect on restraining the deformation of the surrounding rock, and advanced grouting is efficient in enhancing the mechanical parameters of the surrounding rock and reducing the displacement of the surrounding rock. The support optimization engineering application is carried out in the 6# construction branch tunnel of the Fenghuang Mountain tunnel, yielding good results. [ABSTRACT FROM AUTHOR]

Ecological governance projects have great potential benefits, but there is a lack of quantitative evaluation of their impacts in terms of enhancing regional ecological carrying capacity under climate change. To quantitatively evaluate the impact of ecological governance projects on regional ecological carrying capacity, a quantitative evaluation model was developed by coupling the classical ecological footprint and ecological service value theory. This model was validated using the water source treatment project (hereinafter referred to as the "DZ" project) of the Middle Route of China's South to North Water Diversion Project, which is the world's largest water diversion project, as an example. The results showed the following: (1) During the implementation of the "DZ" project, the per capita ecological carrying capacity of the reservoir area experienced a wave-like growth trend, with an increase of 0.103615 hm2 and a yield increase rate of 20.00%. The "DZ" project has outstanding ecological benefits, valued at approximately USD 125.272266 million. (2) The "DZ" project has contributed to the improvement of the ecological carrying capacity in the Henan area of the Danjiang Reservoir by about 10.14%, demonstrating that such projects have a considerable impact on efforts to improve regional ecological carrying capacity under climate change. [ABSTRACT FROM AUTHOR]

The article discusses the construction of a low-impact diversion structure on the Cache la Poudre River in Fort Collins, Colorado, blending water flow delivery, river restoration, and equity-centered design. The project, named the Environmental Learning Center (ELC) Flow Restoration Project, incorporates innovative design elements to protect an instream flow water right valued at $220 million and improve stream health, including fish passage. The project serves as a successful example of hybrid river restoration and diversion design, showcasing the value of low-impact diversions and inclusive design elements for accessibility. [Extracted from the article]

The Weishan Lake serves as a crucial reservoir and regulating lake in the Eastern Route of the South-to-North Water Diversion Project and the ecological health of its lake ecosystem directly impacts the water quality for water diversion. Diatoms are particularly sensitive to changes in water environments, and the composition of diatom communities serves as a significant indicator of the health of aquatic ecosystems. To understand the composition of diatom communities in Weishan Lake and their relationship with environmental factors, thereby providing scientific grounds for the protection of the lake's ecological environment, surface sediment diatoms, water samples, and sediments were collected and analyzed. The study revealed that there are 64 species from 19 genera of diatoms in Weishan Lake, predominantly comprising epiphytic and planktonic species. Dominant species include Fragilaria brevistriata, Achnanthes minutissima, and Stephanodiscus parvus, indicating an overall meso-eutrophic status. According to the diatom composition and biodiversity index, the diatom community was divided into three combination zones. Redundancy analysis (RDA) results indicated that the water environmental factors influencing the composition and distribution of diatom communities in Weishan Lake are TP, TOC, DO, NO2−–N, and Ca2+, collectively explaining 35.60% of the variation in diatom community composition. Due to the influence of agricultural and industrial wastewater runoff, domestic sewage discharge, and cage aquaculture, Weishan Lake is in a mesotrophic eutrophication state. Therefore, it is recommended that strict control over inappropriate human activities in the lake area be implemented in the future to ensure the safety of water quality for water diversion. [ABSTRACT FROM AUTHOR]

Copyright of ASBU Law Journal is the property of Social Sciences University of Ankara and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study performed an evaluation of the groundwater quality of unconfined aquifers in Yangzhou, located in the Yangtze River Delta, eastern China. The study area is the source area of the Eastern Route (ER) of the South-to-North Water Diversion Project (SNWDP), typical of the lower alluvial plain of the lower Yangtze River. Water samples from monitoring wells and domestic wells were collected to analyze common variables (pH, EC), major ions, trace metals, etc. The water quality index method was employed to evaluate groundwater quality in both eastern and western parts of the study area. The study found that the groundwater hydrochemistry is typical of HCO3-Ca and HCO3-Na, similar between the eastern and western parts of the study area. In addition, the eastern part of the study area is more affected by nitrate pollution than the western part due to agricultural activities. The water quality analysis suggests that the groundwater in the western region was slightly better than that in the eastern region. The comparison between different scenarios indicates that the water quality using only major ions can differ significantly from that using all chemical parameters, but may offer some preliminary insights into the groundwater quality useful for conducting further more detailed analysis. Our study shows that using the combination of major ions and heavy metals could provide relatively robust results of the groundwater quality in our study area. Our study has important implications for the assessment of groundwater quality in regions with similar conditions. [ABSTRACT FROM AUTHOR]

To assess the influence of the spherical and supporting radius of swivel hinges on the anti-overturning capability of T-structures and the safety of lower turntables, this study focuses on large-tonnage rotary bridges spanning the South-to-North Water Diversion Project along the Jiaozuo to Tanghe Expressway. The research involved theoretical analysis and numerical simulations to evaluate the stability of the rotary structures and the load-bearing capacity of rotary platforms with varying spherical and supporting radii, and we generated 15 numerical models. The results indicate that the critical eccentricity for T-structure anti-overturning increases with larger supporting and spherical radii, with diminishing returns as the supporting radius decreases. The critical eccentricity for spherical hinges is consistently lower than that seen for flat hinges. The lower turntable's failure characteristics divide it into four zones, as follows: main compressive stress failure at the bottom under the hinge, main tensile stress failure at the top around the hinge, and two other regions less prone to failure. The supporting radius significantly influences compressive and tensile stress failures, while the spherical radius mainly affects the tensile stress area. These results offer insights for the design and construction of large-tonnage rotational bridges. [ABSTRACT FROM AUTHOR]

To address the issue of regional water resource scarcity, water diversion projects have been constructed worldwide. As an essential lifeline project, the prefabricated aqueduct is prevalently utilized in cross-regional water transfer and diversion projects. This paper was based on the prefabricated aqueduct project, which adopted fabricated technologies including the connection technology among the gravity pier, the prefabricated arch ribs, and the prefabricated bent frame columns. The PHC piles, bearing platforms, bent frame columns, arch ribs, and groove bodies were all prefabricated components that were transported to the site for installation. The connections of the prefabricated aqueduct employed to link different components were of such crucial significance that their safety and stability determined whether the overall structure would be compromised. Therefore, the main objective of this paper was to examine the stress and deformation of this prefabricated aqueduct to prevent the occurrence of security risks throughout the entire construction stage. The finite element model was established in Midas Civil, and the entire construction stage was simulated and analyzed. Coupled with on-site monitoring, the stress and deformation of the prefabricated aqueduct were evaluated. The results indicated that the tensile stress, the compressive stress, the vertical displacement, and the lateral displacement of each part of the prefabricated aqueduct met the requirements of the standard, suggesting that the overall structure with the applied connection technology was in a safe and stable state throughout the entire construction stage. [ABSTRACT FROM AUTHOR]

Floods and droughts are becoming common and concurrently occurring in different parts of the world due to changing global climate. Innovative and sustainable water management strategies are necessary to overcome the issues of flooding and drought, especially in large urban regions. This study aims to use abandoned quarries as an innovative and sustainable measure for flood mitigation and improved urban water supply. Chennai, one of the large metropolises of India, is a typical example of a city experiencing periodic floods and droughts. The MIKE11 Nedbor-Afstromings Model (NAM) was used to assess the efficacy of the proposed intervention and temporally varying water diversion strategies among the different water storage options. The approach was also tested with extreme rainfall cases and flood events in 2015, and it was confirmed that the presented method would reduce the surplus flow in the river and improve the water supply. The approach considered here is promising as it is possible to increase the urban water supply and reduce the impact of flooding. The innovative approach has dual benefits and can be adopted in regions with abandoned quarries under changing climatic conditions, leading to frequent flooding and droughts. [ABSTRACT FROM AUTHOR]

Recent studies in human geography and political ecology have examined the anticipatory politics of proposed infrastructure and their effects. Less work analyses how speculation and rumour are mobilised to promote or resist such infrastructures. In this paper, I examine how speculative ideas about long-proposed hydropower dams and transbasin water diversions in the Salween River Basin are strategically deployed by differently placed actors working towards project development or demise. I draw on empirical research on the proposed Yuam River water diversion project in Northwest Thailand and near the Thai–Myanmar border. I develop a conceptualisation of proposed infrastructures as amorphous as they constantly change form and enrol a shifting network of actors, and development plans and imaginaries. The Yuam diversion becomes amorphous through the contested 'facts' of the case and over time. I illustrate this using two longitudinal examples. First, infrastructure is made amorphous through protracted development processes for the Yuam diversion and earlier iterations. Second, I examine speculative ideas about how the Yuam diversion is intertwined with proposed dams in the Basin including the Hatgyi Dam in Myanmar. In this case, the lack of confirmed project developers and financiers for the Yuam diversion, and rumours of Chinese actors' involvement under the Belt and Road Initiative, creates strategic space for project promotion and resistance. What is at stake is not just theorising proposed infrastructures as speculative ideas but how the 'amorphous' qualities of infrastructure are deployed strategically, by whom, and to what effect. [ABSTRACT FROM AUTHOR]

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The Haidong Tunnel is one of the four soft rock tunnels of the Central Yunnan Water Diversion Project (CYWDP), where large deformation hazards of soft rock occur frequently, which seriously affect construction safety. The effect of highly prestressed anchor cable support was studied based on the active support test in the No. 3 branch tunnel of Haidong Tunnel. Firstly, the geological conditions and failure causes were analyzed on the basis of the results of geological survey, in-situ test, and rock laboratory test. Then, the Mohr circle form of the highly prestressed anchor cable active support theory for the support of bedded rock mass was given in combination with the excavation compensation method. It is considered that the prestress active compensation value required for the bedded rock mass is larger than that for the homogeneous rock mass. The deformations of rock mass under both passive and active supports were analyzed by numerical simulations. Furthermore, the 'pressure bubble' mechanical model for anchor cable support of bedded rock mass in Haidong Tunnel is given. Field monitoring results show that the highly prestressed anchor cable support can control rock mass deformation well, with a maximum deformation of about 200 mm. The prestressed anchor cable is effective in the bedded stratum, which makes the stress of rock mass uniform and reduces the risk of failure of steel arches due to local bias. Meanwhile, the expansion of plastic zone was efficiently controlled, which is of positive significance for the overall stability of rock mass. [ABSTRACT FROM AUTHOR]

Objective: To investigate the water quality and its microbial community structure in four different functional water bodies-reservoirs, the South-to-North Water Diversion East Route water, seawater bathing beaches, and seawater aquaculture areas. Methods: Sampling was carried out in each of the four functional areas of water bodies. Through 16S rRNA high-throughput sequencing technology, combined with the physical and chemical indicators of water quality, the current status of water quality as well as the differ- ences in the structural composition of microbial communities in different functional water bodies were analysed and compared. Results: The water quality of the sea bathing beach was the best compared to the other three water body functional areas, TN was high in the reservoir, COD and TN were higher in the water of the east line of the South-to-North Water Diversion, and the concentration of reactive phosphate was slightly higher in the sea water aquaculture area. Species richness as well as species diversity were highest in the four wa- ter body functional areas in the sea bathing area, and lower in the reservoir and mariculture area. Differences in bacterial community composition were mainly at the genus level. Reservoir and South-to-North Water Diversion East Line water compositions were similar compared to the other two functional areas, mainly due to the fact that the winter water supply of the Echinohontan Reservoir only comes from the South-to-North Water Diversion East Line water. In addition there were differences in the bacterial composition between the sea bathing area and the sea water aquaculture area, and aquaculture and the consequent changes in the physicochemical factors of the water quality had a greater impact on the differences in the composition of the bacterial communities in the two areas. Total nitrogen and total phosphorus were the main environmental factors affecting the bacterial community composition. Conclusions: The water quality of the sea bathing beaches is the most compliant with the standards, while the high TN in the reservoirs and the water of the South-to-North Water Diversion Eastern Route increases the risk of eutrophication of the water bodies and needs to be focused on. The source of im- poundment, high TN, COD and reactive phosphate concentrations have a greater impact on causing differences in the bacterial community composition of the four functional water bodies. [ABSTRACT FROM AUTHOR]

In addressing sediment accumulation challenges in the water diversion canal and enhancing both water utilization and ecological conditions, this study introduces a fish mouth engineering design, akin to the sediment reduction strategies used at the Dujiangyan water conservancy hub. A specialized two-dimensional hydrodynamic and sediment transport model was developed, specifically tailored to the Qixing Canal section in Ningxia. Utilizing SMS software, an unstructured grid division of the study area was executed. The research employed simulations under two distinct scenarios: direct water diversion and fish mouth engineering at the canal head. These simulations were pivotal in analyzing the variations in sedimentation thickness and sediment concentration across different flow rates and irrigation cycles. It was observed that the use of the fish mouth engineering for water diversion significantly improved the sedimentation thickness, underscores the efficacy of the fish mouth model in altering the structural characteristics of water flow and achieving a redistribution of water flow and sediment within the canal. This approach to fish mouth diversion and sediment reduction substantially curtails sediment accumulation in the irrigation canal, presenting a viable strategy for canal head design in the self-flow irrigation areas of the Yellow River. This research result provides certain reference value for water conservancy engineering organizations. [ABSTRACT FROM AUTHOR]

The provinces of Ubon Ratchathani and Sisaket experienced severe flood events in 1938, 1978, 2002, and notably in 2019, when widespread flooding occurred in late August. A comprehensive study using MIKE FLOOD medelling was conducted to consider the causes of flooding in these areas and explore potential flood prevention measures. The results highlighted the crucial role of changes in upstream water discharge in triggering extensive flooding. It was found that water inflow from the upstream basin was a primary factor contributing to major flood incidents in both provinces. The study demonstrated that river dredging could reduce flood-prone areas in Sisaket by 52.38%, while its impact in Ubon Ratchathani was predicted to be minimal. The diversion of water from the upstream basin could reduce flooded areas by a minimum of 43.81% to a maximum of 49.83%, showing that strategic water diversion could contribute to flood mitigation efforts. Moreover, eight runoff stations within the upper basin of the study area were also found to be vital for effective flood warning systems. Effective flood mitigation in the area requires a combination of upstream water flow management, strategic dredging, and robust flood warning systems. The insights gained from this study can inform future flood prevention and management strategies to reduce the vulnerability of these regions to destructive flood events. [ABSTRACT FROM AUTHOR]