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

SHEN Jian, YUAN Song

The Jingjiang reach of the middle reaches of the Yangtze River is connected to Dongting Lake through three outlets,forming an extremely complex and far-reaching relationship between the rivers and lakes.The operation of the Three Gorges Project has changed the natural water and sediment process in the Jingjiang River downstream of the dam.This leads to “flattening” flood processes in the main stream,extended middle water period,and an increase in low flow,which has promoted the continuous response of the three outlets to the above water and sediment conditions.Meanwhile,this paper employs a series of long-term measured hydrological consolidation data and river channel terrain observation results from nearly 70 years.Based on this,the response characteristics of the three outlets to the water and sediment variation process of the Jingjiang River are analyzed,and the flow and sediment diversion,river regime,and erosion and sedimentation evolution laws in the entrance area are summarized.The results show that in the same inflow conditions before and after the operation of the Three Gorges Project,the diversion ratio of three outlets decreases,and the sediment diversion corresponds to the sediment from the upstream branch city.Additionally,the sediment diversion ratio continues its gradually increasing trend.After the impoundment and operation of the Three Gorges Reservoir,the riverbed of three outlets is generally in a state of erosion,with a total erosion amount of 51.47 million m³ from 2003 to 2011 and 99 million m³ from 2011 to 2016.The entrance areas have been expanded,but the actual flow capacity has not been significantly improved.

Rajiv Gurung, Christopher Tirkey, Kishore Kumar Takri et al.

Access to improved drinking water and sanitation has been declared a fundamental right by the UN General Assembly. However, around 25 and 50% of the global population lacked access to safely managed drinking water and improved sanitation in 2020, respectively. India, the second most populous country in the world, has around 3.7 and 31% of its population without access to improved drinking water and sanitation, respectively. This paper explores the factors determining a household's access to improved drinking water and sanitation in India, using India Human Development Survey (IHDS) II data. The results indicate that urban households with bigger family sizes, with fewer rooms, married but uneducated household heads, belonging to forward castes, were more likely to have access to improved drinking water. Similarly, households with married female heads, belonging to forward castes, small household sizes, older aged heads with primary education, from Non-EAG (Empowered Action Group) states, located in urban areas, earning higher incomes and having more rooms were more likely to have access to improved sanitation. Findings suggest subsidized improved water and sanitation services and an increase in public investment to make these facilities affordable for poor rural households. HIGHLIGHTS A considerable share of the global population remains deprived of safe drinking water and sanitation.; There is an urgent need to understand the factors influencing their access as any policy intervention aiming to improve sanitation and drinking water problem must first identify the population at risk.; Studies on the determinants of access to improved drinking water and sanitation in the Indian context are limited.;

Kuldeep Singh Rautela, Dilip Kumar, Bandaru Goutham Rajeev Gandhi et al.

ABSTRACT The estimation of stream discharge is an essential component of planning and decision-making. It is highly correlated with many development activities involving water resources. The study of transportation of sediments in the rivers will help us to develop policies and plans for soil conservation, flood control, irrigation, navigation, and aquatic biodiversity problems. Using data-driven models such as Artificial Neural Networks (ANNs), modeling of streamflow and sediment transport is frequently adopted due to their applicability and problem-solving ability. This study has used three training algorithms such as Scaled Conjugate Gradient (SCG), Bayesian Regularization (BR), and Levenberg-Marquardt (LM) to simulate the streamflow and Suspended Sediments Concentration (SSC). After optimizing the best training algorithm based on the model efficiency parameters, L-M based-ANN model has been used to predict streamflow for two years and the modeling of suspended sediments was validated with the help of observed data. The result shows that the simulated results tracked the streamflow as well as SSC with the desired accuracy based on the model efficiency parameters such as coefficient of Determination (R2), Nash Sutcliffe Efficiency (NSE), Root Mean Square Error (RMSE), and Root Mean Square Deviation (RMSD). The study's outcomes reveal that in the streamflow the concentration of suspended sediments is significantly affected by the base rock material, glaciers covered by debris, and moraine-laden ice. The transportation of the sediments is high in the Alaknanda basin as compared to the other basins and the previous studies. This might happen due to the severe anthropogenic activities in the surrounding basin.

Yiran Li, Chuanjie Zhang, Yong Niu

Rainfall interception (I) can considerably influence the transport process of water. The revised sparse Gash model (RSGM) is a tool for determining the I, which assumes that the two climate parameters in the model are equal for all storms. However, few studies have provided additional cases to reexamine the correctness of this assumption and investigated the response of I of single storms to the time-step variability in climatic parameters. Hence, rainfall partitioning was measured during the growing season in 2017 for Pinus tabuliformis, Platycladus orientalis, and Acer truncatum in Northern China, and we ran RSGM on an event basis using different time-step climatic parameters (storm-based, monthly, and fixed) to estimate I. In summary, the modeling accuracy of both cumulative I and individual I was enhanced by increasing the time step of the climatic parameters in this study. These positively support the assumption in the RSGM. These results suggest that it is more appropriate to run the RSGM using fixed climate parameters to estimate I for these tree species during the growing season in northern China. Additionally, the assumption in the RSGM should be appealed to be further confirmed across the widest possible range of species, regions, and time scales. HIGHLIGHTS The reasonableness of an assumption in the revised sparse Gash model (RSGM) was reexamined.; Effects of time-step climatic parameters on the RSGM were compared.; Fixed climatic parameters were more appropriate for the simulation in the studied species.; Simulations of single intercepted events are problematic no matter the time step.; Good model accuracy is from complementation between small and large rainfall events.;

JIANG Zisheng, WANG Qisong

Based on the analysis of the statistical characteristics of storm surges which have a great impact on the Maozhou estuary,this paper constructs a typhoon storm surge model based on ADCIRC storm surge model and jetsner wind pressure model,calibrates and verifies the parameters of the model through three typical months and ten typical typhoons,calculates the probable maximum typhoon storm surge when the typhoon lands in Macau with the heading direction of 340° by designing different parameter combinations among typhoon center pressure,moving speed,maximum wind speed radius and typhoon path,and simulates the water augmentation process of Maozhou estuary under the probable maximum storm surge.The calculation results can provide a reference for storm surge prevention and mitigation in Maozhou estuary engineering construction.

Sneha Unnikrishnan, Mohd Hashim Khan, Karthikeyan Ramalingam

The objective of this study was to isolate a potent dye-degrading microbe that can be used to reduce the pollution caused by industrial dyes. Reactive red 198 is an extensively used textile dye and is a major environmental pollutant in water bodies. In this study, a bacterial strain was isolated from sea sediments and identified as Acinetobacter baumannii with 16S rRNA sequencing. The isolated bacteria were immobilized in calcium alginate and decolorization studies were carried out to determine the optimum pH, temperature, dye concentration, inoculum volume, and static/agitated condition using the one factor at a time (OFAT) approach. The Box-Behnken design, a type of response surface methodology, was adopted to improve the degradation efficiency. At 37°C using an inoculum volume of six beads, 96.20% decolorization was observed in 500 mg/L of reactive red 198 after 72 h. Dye degradation was confirmed with UV-visible spectroscopy and Fourier-transform infrared (FTIR) spectroscopy studies of the dye and degraded metabolites. Microbial toxicity studies using Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa and phytotoxicity studies using Vigna radiata proved that the toxicity of the dye was significantly reduced after degradation. We can conclude that the isolated A. baumannii strain is an efficient dye-degrading microbe that can be used to reduce the pollution caused by industrial dyes. Keywords: Immobilization, Box-Behnken design, Response surface methodology, Microbial toxicity, Dye degradation

PATRÍCIA BORBA VILAR GUIMARÃES, YANCO MARCIUS DE ALENCAR XAVIER, FABRÍCIO GERMANO ALVES

O trabalho visa o questionamento acerca do respeito ao princípio constitucional do desenvolvimento sustentável como limitador da atividade econômica no Brasil, através da análise de aspectos aparentemente contraditórios acerca da produção do agronegócio para a indústria de biocombustíveis, intensiva no uso de recursos hídricos, em especial, proveniente de fontes subterrâneas. A análise da lei de águas, da legislação aplicada aos biocombustíveis e os princípios ambientais é realizada no sentido de contrapor os mandamentos legais ao cenário de produção de biocombustíveis no Brasil.

GUAN Xian

Ying-kui Wang, Chun-bo Jiang

Experiments in an open flume model and spillway tunnel model were carried out using drag reduction techniques. Two drag reduction techniques were adopted in the experiments: polymer addition and coating. The drag reduction effect of a polyacrylamide (PAM) solution and dimethyl silicone oil coating were studied in the flume model experiments, and the results were analyzed. Experiments were then carried out with a model of the Xiluodu Hydropower Station, the second largest dam in China. In order to reduce the resistance, the spillway tunnels were internally coated with dimethyl silicone oil. This is the first time that these drag reduction techniques have been applied to so large a hydraulic model. The experimental results show that the coating technique can effectively increase flood discharge. The outlet velocity and the jet trajectory distance are also increased, which enhances the energy dissipation of the spillway tunnel.

Qiao Lifang, Zhang Yichuan, Cao Wei

An evaluation model for the rationality of the landscape design of urban rivers was established with the analytic hierarchy process (AHP) method so as to provide a foundation for updating the landscape design of urban rivers. The evaluation system was divided into four layers, including the target layer, the comprehensive layer, the element layer, and the index layer. Each layer was made of different indices. The evaluation standards for each index were also given in this paper. This evaluation model was proved tenable through its application to the landscape design rationality evaluation of the Weihe River in Xinxiang City of Henan Province. The results show that the water quality, space, activity, facility, community, width of vegetation, sense of beauty and water content are among the most influential factors and should be considered the main basis for evaluating the rationality of the landscape design of urban rivers.

José Gonzaga da Silva, Itabaraci Nazareno Cavalcante, Maria da Conceição Rabelo Gomes et al.

A área da presente pesquisa está situada no município de Fortaleza, abrangendo uma extensão de 59 km2, na porção norte e leste do município, tendo como limite o Oceano Atlântico. O objetivo desse trabalho é avaliar os fatores potencialmente influentes na qualidade das águas subterrâneas em toda região urbanizada da faixa costeira do município de Fortaleza. A metodologia constou do levantamento bibliográfico, cadastro de poços, tratamento preliminar dos dados, etapas de campo e interpretação dos dados. Conclui-se que as principais fontes de poluição cadastradas e analisadas para este trabalho incluem-se: lançamento de efluentes de esgotos domiciliares, associadas a ausência de saneamento básico, fossas sépticas, presença de resíduos sólidos de várias origens e intrusão salina nos aqüíferos, tendo em vista ao constante bombeamento de poços instalados em pontos mais sensíveis a salinização.

HE Qi-lian, JIANG Xian-qun

MO Hai-hong, LIANG Song, YANG Yi-bo et al.

Antônio Mitsuo Aoki, Gustavo Olivieri Lopes

Pescarias são técnicas utilizadas para a retirada de ferramentas e objetos caídos dentro de poços tubulares durante a perfuração e manutenção dos mesmos. As pescarias ocorrem devido a falhas técnicas ou materiais e podem ser prevenidas se forem tomadas algumas providências antes e no decorrer dos serviços. Os pescadores são das mais variadas formas e modelos, ficando sempre a cargo da equipe de trabalho decidir qual será melhor utilizada durante a operação. Nos poços tubulares para água os casos mais comuns são as pescarias de equipamentos de bombeamento, de brocas tricônicas e bits pneumáticos.

Claudia Bessouat, Griselda Castagnino, Jorge De Los Santos, Jorge et al.

La vulnerabilidad es una propiedad intrínseca de los sistemas de agua subterránea. El Mapa de Vulnerabilidad del acuífero de Raigón se construyó utilizando la metodología DRASTIC (EPA), un sistema paramétrico que incluye siete características del acuífero. Para la realización del estudio se confeccionaron mapas temáticos (topografía, freatigrafía, suelos, geología), se definió la geometría del sistema y se ajustó un modelo numérico de flujo subterráneo. El Índice General de Vulnerabilidad se obtuvo así para cada punto del área. Su entorno numérico fue de 51 a 194 (entre 23 a 226 de valores extremos posibles), dividido en tres rangos. El 13% pertenece a áreas de bajo índice de vulnerabilidad, el 68% de índice medio y el 19% de alto índice. La Carta de Vulnerabilidad General del Sistema Acuífero de Raigón constituye una base de gestión para uno de los principales recursos hídricos del Uruguay y una importante herramienta para el Ordenamiento Territorial y la protección del Medio Ambiente.

Thiago Rossi Viana, André Celligoi

O desenvolvimento econômico e populacional verificado na cidade de Londrina desencadeou uma demanda progressiva de água para o abastecimento. Assim, a determinação e o estudo das reservas das águas subterrâneas do Aqüífero Serra Geral, sobre o qual a cidade está inserida, se tornam de vital importância. Em virtude das características litológicas das rochas vulcânicas da Formação Serra Geral, o modo de ocorrência da água subterrânea fica restrito às descontinuidades da rocha, que são estruturas intrínsecas de derrames vulcânicos, bem como fraturamentos e falhamentos de origem tectônica. A reserva reguladora foi calculada em função da análise das curvas de recessão do ribeirão Cafezal na zona urbana de Londrina, observando-se o volume de água infiltrado e a vazão do rio nas longas estiagens. Foi realizada, também, uma análise cadastral que permitiu plotar os poços na zona urbana de Londrina. A partir de dados pluviométricos foi possível estabelecer o total das águas destinadas à recarga, de forma a calcular o volume hídrico sazonal acumulado no meio aqüífero, ou seja, a reserva reguladora. Assim sendo, confrontando os números da quantidade da água subterrânea disponível à exploração com a vazão total dos poços cadastrados, pode-se obter a quantidade do volume da reserva reguladora explorado pelos poços cadastrados.

Ivan Edilberto Mendes Teixeira

A Formação Açu é uma unidade litoestratigráfica da Bacia Potiguar, que está situada no extremo nordeste do Brasil. Boa parte dos reservatórios desta unidade são portadores de água de baixa salinidade, amplamente explotados para consumo humano e irrigação. Estudos hidrogeológicos desenvolvidos na região atestam a ocorrência de fluxo hidrodinâmico subterrâneo nesta unidade que, especialmente na porção média inferior, é constituída por espessos pacotes arenosos de excelente permeabilidade, que a caracterizam como o melhor sistema aqüífero da Bacia. Este fluxo é responsável pelo contato óleo/água inclinado, característico das diversas acumulações de hidrocarbonetos descobertas em seus reservatórios, algumas com adiantado estágio de biodegradação. O aporte de água se dá a partir da área de recarga, associada à superfície de afloramento localizada na borda da Bacia, ou via drenança vertical descendente de águas de unidades estratigráficas sotopostas, especialmente a Formação Jandaíra. As análises de diagramas hidroquímicos e de razões entre componentes iônicos atestam a procedência continental das águas da Formação Açu. Este estudo tenta definir um zoneamento para as águas da Formação Açu, com base na interpretação hidroquímica, incluindo o comportamento da salinidade, e nas características hidrodinâmicas da formação, inclusive na relação regional entre a sua carga hidráulica e aquela da Formação Jandaíra.

黎冠旺, 陈邦治