Hasil untuk "River, lake, and water-supply engineering (General)"

João Henrique Alliprandini da Costa, João Henrique Alliprandini da Costa, Jansen Zuanon et al.

IntroductionTemporary freshwater habitats are characterized by cyclical flooding and drying that create highly dynamic conditions for fish community assembly. These environments can exhibit high spatial and temporal variability in community structure driven by local topography, distance to source habitats and interannual variation in rainfall, which affects connectivity dynamics. As such, they provide unique opportunities to test hypotheses about the processes shaping metacommunities. Here, we investigate these processes in temporary freshwater habitats of the Atlantic Forest.MethodsWe sampled 36 temporary pools and 36 roadside ditches throughout 2024, recording 1,545 individuals from 20 species. We tested if community composition differs between habitat type and rainfall periods and whether beta diversity components were associated with local environmental and spatial predictors.ResultsFish community composition did not differ significantly between habitats or hydrological periods, but temporal variation in spatial beta diversity was consistently high and influenced by turnover. During the dry period, nestedness was positively correlated with differences in volume for temporary pools and roadside ditches. Additionally, during the wet period, turnover in ditches was correlated with differences in pH. In temporary pools during the wet period, turnover increased with differences in distance to the nearest stream.DiscussionHigh turnover for both habitats and periods suggest spatial processes such as dispersal limitation and colonization history are key drivers of community structure in those temporary aquatic habitats. Nestedness correlations with differences in volume in the dry period indicate that greater habitat availability promotes species accumulation under low connectivity, where dispersal occurs possibly only by overland displacement. Meanwhile, turnover correlation with differences in pH for ditches in the wet period is consistent with mass effect dynamics under higher connectivity conditions, with pH acting as a proxy for stream water influx. Turnover correlation with differences in distance to the nearest stream for pools during the wet period suggest colonization by highly tolerant and capable of dispersal species in more isolated sites. Overall, our findings emphasize that beta diversity in temporary aquatic habitats is primarily structured by habitat availability and spatial processes interacting with hydrological dynamics, underscoring that effective conservation must target the entire floodable mosaic rather than isolated sites to maintain this dynamic metacommunity.

Ashok Kumar, Beenish Mushtaq, Rabidyuti Biswas et al.

Abstract Values of individuals and organizations involved in decision‐making processes form the basis for prioritizing outcomes in water governance. The novelty of this study lies in applying values to a specific decision‐making context. It aims to assess the prioritized water governance outcomes and the underlying value systems shaping the actions of the primary water utility responsible for water governance in Delhi, the Delhi Jal Board (DJB). The paper will critically examine the policies and acts of the DJB that drive water governance in Delhi at present, utilizing a values‐based framework in conjunction with secondary literature and expert interviews, to draw a picture of the values reflected. The study does not substantiate the notion of economic values dominating the water‐related decisions; rather, recent policy guidelines indicate prioritization of equitable and fair distribution of water. Findings of this paper show that making the values explicit is largely disregarded in formulating water acts and policies, and values are never elucidated in the public domain, doing which can encourage water policies and practices that are socially, economically, and ecologically viable in the long run. It is expected that this paper will generate a discussion on water values being an integral part of water governance discourses.

Oxana I. Nikitina, Aleksey E. Kosolapov

This study focuses on developing scientifically grounded approaches to transboundary flow allocation in the Ural River Basin, considering ecosystem needs and international approaches to aquatic ecosystem conservation. Amid increasing competition for water resources and climate change, there is a growing necessity to shift from allocating fixed water volumes toward more flexible, ecosystem-oriented solutions. Based on an analysis of international practices, the provisions of the existing agreement on the joint use and protection of water bodies in the Ural River Basin, and an assessment of the current state of its aquatic ecosystems, the study highlights the need to revise established water allocation mechanisms.

LIAN Zhiwei, CHENG Qing, SONG Lixiang et al.

Conventional empirical formulas for calculating the breach discharge of concrete dams often fail to account for the influences of upstream inflow, downstream backwater effects, and irregular breach shapes on dam-break flow, particularly for lake-type reservoirs characterized by high dam height, large storage capacity, and significant inflow. Consequently, there exists a certain deviation between calculated results and actual conditions. To address these limitations, a breach discharge calculation method based on a zero-dimensional (0D) and two-dimensional (2D) coupled model was proposed. The 0D reservoir was conceptualized using water level-storage capacity curves and discharge-storage relationships, while the downstream river channel was modeled using a 2D hydrodynamic framework. The coupling between the 0D and 2D models was achieved through the formulation and solution of a Riemann problem. To represent arbitrary breach geometries, the model modified the elevations of 2D grid nodes at the dam site, enabling accurate simulation of complex flow regimes at the breach boundary and effectively overcoming the shortcomings of traditional empirical formula methods. Taking the Fengshuba Reservoir in Guangdong Province as a case study, the adaptability and rationality of the proposed model were verified by comparing its calculated breach discharge results against those obtained from typical empirical formulas, including the Saint-Venant formula, Schoklitsch formula, U.S. Waterways Experiment Station (WES) formula, and broad-crested weir formula. Based on the analysis of breach discharge reasonableness, the breach discharge calculated by the proposed model was larger than the results of the Saint-Venant, Schoklitsch, and WES formulas. However, since the model fully considered the irregular breach cross-section formed during an actual failure process, the result was slightly smaller than that of the broad-crested weir formula. Furthermore, water balance analysis confirmed minimal model error, indicating that the model accurately reflected the actual breach discharge hydrograph. Additionally, the calculated breach discharge was coupled with a dam-break flood routing model for downstream flood evolution analysis. The simulation results show that a complete dam failure during the flood season would significantly impact Heyuan City and Huizhou City along the main and tributary channels of the East River, while having a lesser effect on Dongguan City and Guangzhou City in the estuary area. The inundation area with water depth exceeding 3 meters reached 561.87 km². The model effectively simulated the propagation of dam-break floods, with results consistent with flood evolution patterns, clearly delineating the inundation impact. This provides critical technical support for simulating dam-break floods from concrete dams and formulating safety emergency plans for reservoir failure incidents.

Gustavo Gabbardo dos Reis, Rodrigo Cauduro Dias de Paiva, João Paulo Lyra Fialho Brêda et al.

ABSTRACT Due to the frequent occurrence of extreme hydrological events in the South American rivers, this work aims to develop a hydrological monitoring platform open to the public, with a wide and intuitive access, using resources of an online geographic information system, in order to contribute to a better understanding of the behavior of these natural disasters. SARDIM (South America River DIscharge Monitor) has been developed using programming resources in languages such as Python and JavaScript. The data of the platform are derived from results of a continental scale hydrological simulation model (MGB - South America) that uses, among other information, precipitation data from the GPM (Global Precipitation Measurement) mission and from the MSWEP (Multi-Source Weighted Ensemble Precipitation) product. After a statistical analysis of the model results, the platform is updated daily and operationally, with new data on the flow duration and the return period of river flows, allowing the identification, monitoring and evaluation of the intensity of extreme hydrological events in South America.

Yan Shi, Shipeng Yang, Weiwei Chen et al.

Human-water harmony in the Yellow River Basin has an important influence on promoting ecological protection and high-quality development in the Yellow River Basin. This paper explores the degree of harmony between humans and water in the provinces of the Yellow River Basin. Based on the provincial-level data of nine provinces from 2001 to 2020, a human-water harmonious coupling coordination degree model was constructed, and the spatial and temporal analysis of the coupling coordination characteristics of nine provinces was carried out utilizing ArcGIS software. The results revealed that: (1) From the point of view of human-water harmony, from 2001 to 2020, China's human-water relationship was on the rise, from reluctant coupling coordination to good coupling coordination. (2) Qinghai, Gansu, and Sichuan provinces have the most significant increase in human-water harmony, from on the verge of a dysfunctional decline to quality coupling coordination. (3) From 2001 to 2011, the human system's comprehensive index was inferior to that of the water system's comprehensive index. In 2003, the comprehensive index of human and water systems was the largest. From 2012 to 2020, the human system's comprehensive index was higher than the water system. However, in 2015, the two indices diverged significantly HIGHLIGHTS A human-water harmony model was established to evaluate the human-water relationship in the Yellow River Basin.; The spatial and temporal analysis of human-water harmony in nine provinces in the last 20 years was carried out.; Put forward relevant suggestions according to the evaluation results.;

Claudia Bertini, Elena Ridolfi, Luiz Henrique Resende de Padua et al.

Accurate and precise rainfall records are crucial for hydrological applications and water resources management. The accuracy and continuity of ground-based time series rely on the density and distribution of rain gauges over territories. In the context of a decline of rain gauge distribution, how to optimize and design optimal networks is still an unsolved issue. In this work, we present a method to optimize a ground-based rainfall network using satellite-based observations, maximizing the information content of the network. We combine Climate Prediction Center MORPhing technique (CMORPH) observations at ungauged locations with an existing rain gauge network in the Rio das Velhas catchment, in Brazil. We use a greedy ranking algorithm to rank the potential locations to place new sensors, based on their contribution to the joint entropy of the network. Results show that the most informative locations in the catchment correspond to those areas with the highest rainfall variability and that satellite observations can be successfully employed to optimize rainfall monitoring networks. HIGHLIGHTS This study proposes a method to evaluate and optimize an existing rain gauge network using satellite observations.; The most informative locations in the catchment are identified using a greedy ranking algorithm.; The resulting optimal network provides higher joint entropy with fewer sensors.; The most informative locations reflect those with highest variance.;

I. Gordin, Yelena Ryumina

Preferential settlement along the coasts of water bodies (rivers, lakes, seas), dictated by a variety of production and recreational factors, has always been accompanied by environmental disruptions. A specific complex of social, environmental and economic problems arose with the beginning of mass cottage development of Russian coasts. At the same time, certain environmental risks were ignored. Until that time, the country had strict restrictions on the approach of dwellings to water and the operational regimes of households in the water protection zone. Particularly strict regulation for construction and operation of dwellings existed for the coasts of sources of communal water supply to cities and rural settlements and in resort and recreation zones. Today, coastal development is in many ways a chaotic process, accompanied by a wide range of legal and environmental violations. A critical situation developed on the sources of water supply in Moscow, at water supply facilities in other cities of the Russian Federation, on the sea coasts of the Krasnodar Krai and Crimea. Residents of prestigious coastal settlements form a large social group with a specific mentality. Very often it is based on a persistent desire to ignore environmental-legal imperatives for the sake of possessing expensive real estate and elitist recreation conditions. The methodology for study of the situation, based on the general principles of systemic analysis of socio-environmental-economic processes, makes it possible to significantly bring the economic interests of the social group in question closer to environmental and state interests. There is proposed a concept of improving the situation through proof of the inevitable depreciation of coastal real estate due to environmental degradation of water bodies on the banks of which unregulated development is conducted. At the same time, both the deterioration of the recreational climate up to a complete discomfort and the immediate economic losses of the population expressed by drop in the price of land and households in the real estate market, are equally important factors of depreciation.

H. C. Jhúnior

YAO Kai, ZENG Kunxiang, ZHONG Yujian et al.

Based on the self-developed loess-reinforced organic materials of Chengdu university of technology,and combined with ecological considerations,this paper proposes the organic material- three-dimensional planting blanket slope protection technology,analyzes the slope protection effects of organic materials and organic materials- three-dimensional planting blanket on loess erosion characteristics and slope runoff &sediment yield through artificial simulated rainfall test,as well as compares and evaluates the erosion resistance.The results show that:Organic materials can prevent the formation and development of rills on loess slopes,weaken the ability of slope runoff to erode the soil,and improve the slope stability;There is almost no erosion on three-dimensional planting blanket slope,so the slope stability is good;Under the same time,the runoff of the organic material slope is higher than that of the bare slope,while the cumulative runoff of the organic material- planting blanket slope is lower than that of the bare slope,and the total sediment yield of both is much smaller than that of the bare slope;The organic material- three-dimensional planting blanket slope protection is divided into two processes:in the first stage,the slope is protected and reinforced by organic materials,and in the later stage,the slope is mainly protected by three-dimensional planting blanket.Therefore,the combination of the two is more conducive to improving the resistance of loess to rainfall erosion.

ZHOU Bin

In recent years,arch ring types of arch dam tend to be diversified.Some scholars put forward the cardioid as the horizontal arch ring of arch dam.However,the stress characteristics of the cardioid are not fully considered when the arch ring is arranged,so there are certain defects.It is of great significance to further study the nature of the cardioid and optimize the arrangement of the cardioid arch ring for the development of arch dam design technology.This paper finds out some basic properties for cardioid as the horizontal arch ring through mathematical derivation,proposes a new type of cardioid arch ring arrangement with considering the stress characteristics,and calculates the stress of the dam surface by the multi-arch beam method based on the shape of a similar arch dam with cardioid in an existing project.The results show that the stress of the new arch dam is not much different from that of the original arch dam,so it can be preliminarily judged that the use of the cardioid in the shape design of arch dam is feasible,which can be considered as a supplement to the common ring types of arch dam and further verified by the engineering.

Guilherme Costa Rodrigues Neto, Erlandson de Vasconcelos Queiroz, João Marcelo Costa Barbosa et al.

ABSTRACT We investigated the influence of fictitious boundary distance, a parameter of MFS, to determine piezometric levels of two unconfined sedimentary aquifers assuming Dupuit-Forchheimer and steady-state flow hypothesis. Two study areas were modelled: Guariroba’s Environmental Protection Area, in Mato Grosso do Sul State, Brazil, and Juazeiro do Norte City, in Ceará State, Brazil. It was observed that in order to use the MFS as a numerical method in modeling groundwater flow, it is necessary to determine the best distance value of the fictitious boundary. This value can be chosen from the use of field data within the analyzed domain, where the relative error is a parameter to be minimized. Applying this methodology and comparing with the results of the MODFLOW application for the same set of initial data, we concluded that the MSF allows to estimate the piezometric level values within the analyzed domains and that the results of the statistical comparison between them point to the need to investigate the representativeness of both methods to determine which one is most appropriate for modelling the groundwater flow in each region.

Irina L. Grigoryeva

The article presents the results of the study of the winter hydro/chemical regime of the Uglich reservoir which is the second stage of the Volga-Kama cascade of reservoirs. In winter period the main influence on the formation of the hydrochemical regime of the Uglich reservoir is exerted by water coming from the Ivankovsk reservoir which located upstream. It was found that water in the reservoir is hydrocarbonate, mineralization varies from 243 to 351 mg per liter, calcium and magnesium concentrations reach 60.9 and 17.5 mg per liter. Concentrations of mineral phosphorus in the reservoir are 0.043–0.076 mg per liter, total gross phosphorus in the upper relief of the Uglich HPP reach 0.138 mg per liter, nitrate concentrations are 0.14–0.84 mg per liter. The main indicators of hydro/chemical regime of the Uglich reservoir have spatio-temporal variability. Its change from year to year, as well as from target to target. Global climate changes have not yet had a significant impact on the winter hydro/chemical regime of the reservoir.

Trần Ngọc Huy, Huynh Tan Dat

Fabio Ambrogio, E. Comino, Laura Dominici et al.

S. Hussaina, A. P. Trzcinskia, H. M. A. Asghara et al.

Marcela Maciel de Araújo, Claudia Zveibel Toporovski Rebelo, Tatiane Nogueira Aikawa et al.

Muitos parâmetros utilizados nos modelos de intrusão de vapores provêm das características do solo e das edificações que são difíceis de caracterizar, além disso, a maioria desses modelos considera a propagação forçada do vapor para o interior das edificações. Ass im sendo, os resultados obtidos nos modelos usuais para obtenção do fator de atenuação pode muitas vezes não representar não a real situação deste risco. Nesse contexto, realizou uma pesquisa bibliográfica visando a identificação e seleção dos métodos mais adequados a serem utilizados. O método que considera o fluxo ascendente do metano, além d os resultados de subslab se mostrou mais adequado.

Juan Felippe Santiago de Vasconcellos, Fabiana Valéria da Fonseca

The use of Advanced Oxidation Processes for remediation of contaminated areas has become an effective alternative to the destruction of contaminants when applied directly to soil and groundwater or through the treatment systems. This paper aimed to evaluate the cost of investment and operating a Pump & Treat remediation system to use peroxone as a treatment form for groundwater contaminated with chlorinated ethenes. The remediation system considered as hydrogeological characteristics of the study area and contaminants. The costs related to the equipment and materials necessary for the implementation of the system were considered as investment costs, while the operational costs considered electricity, hydrogen peroxide, labor, maintenance, administration, and laboratory analysis of groundwater. The results indicated that approximately 20% of the investment cost is associated with a treatment step and the operating cost step was R$ 551,484.86 (Year 1), R$ 606,913.32 (Year 2) and R$ 336,352.53 (Year 3), demonstrating an advantage over the traditional method of treatment with activated carbon.