scholarly journals Fluxo e armazenamento de água em aluvião do semiárido pernambucano para abastecimento de pequenas comunidades

2020 ◽  
Vol 55 (4) ◽  
pp. 479-497
Author(s):  
Wendell José Soares dos Santos ◽  
Anderson Luiz Ribeiro de Paiva ◽  
Artur Paiva Coutinho ◽  
Jaime Joaquim da Silva Pereira Cabral
Keyword(s):  
Visual Modflow

A Região Nordeste tem grande parte do seu território inserida no semiárido, que é caracterizado por níveis pluviométricos anuais relativamente baixos, e onde a situação de acesso à água é agravada nas zonas rurais com o abastecimento convencional deficitário. Uma das alternativas para essas regiões é a utilização da água subterrânea, porém muitas vezes esses mananciais são explorados sem conhecimento do seu comportamento. Para auxiliar os gestores a entender e gerenciar melhor os aquíferos, faz-se uso de modelos computacionais que representam a situação do ambiente real. O presente trabalho objetivou avaliar o acúmulo de água na aluvião em um trecho de rio dessa região e desenvolver um modelo numérico de fluxo subterrâneo do meio poroso. Foram realizados testes de infiltração com o método Beerkan em três pontos da área de estudo com coletas para análise granulométrica do solo, onde foi possível obter a curvagranulométrica e os parâmetros hidrodinâmicos e construir as curvas de infiltração, de retenção de água e de condutividade hidráulica do solo. Caracterizou-se o solo como preponderantemente arenoso, com tempo de infiltração variando com a profundidade, e seus valores médios de condutividade hidráulica e de umidade saturada foram de 1,84 x 10-4 m/s e 0,44, respectivamente. O solo apresentou baixa capacidade de retençãopara os pontos ensaiados. Construiu-se um modelo da aluvião utilizando o programa computacional Visual MODFLOW, e, com o monitoramento dos níveis de água, alcançou-se um modelo numérico satisfatório. Os resultados obtidos por mapas potenciométricos de cargas hidráulicas ajustaram-se às observações. Também foi possível observar o rebaixamento do lençol freático, apresentando situação crítica em cenários futuros, com o prolongamento da estiagem.

scholarly journals Proposing the Optimum Withdrawing Scenarios to Provide the Western Coastal Area of Port Said, Egypt, with Sufficient Groundwater with Less Salinity

Water ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 3359
Author(s):  
Mohamed Abdelfattah ◽  
Heba Abdel-Aziz Abu-Bakr ◽  
Ahmed Gaber ◽  
Mohamed H. Geriesh ◽  
Ashraf Y. Elnaggar ◽  
...  
Keyword(s):  
Seawater Intrusion ◽  
Coastal Aquifer ◽  
Sustainable Management ◽  
Groundwater Resources ◽  
Field Investigation ◽  
Visual Modflow ◽  
Groundwater Abstraction ◽  
Human Needs ◽  
Western Area ◽  
Port Said

Recently, groundwater resources in Egypt have become one of the important sources to meet human needs and activities, especially in coastal areas such as the western area of Port Said, where seawater desalination cannot be used due to the problem of oil spill and the reliance upon groundwater resources. Thus, the purpose of the study is the sustainable management of the groundwater resources in the coastal aquifer entailing groundwater abstraction. In this regard, the Visual MODFLOW and SEAWAT codes were used to simulate groundwater flow and seawater intrusion in the study area for 50 years (from 2018 to 2068) to predict the drawdown, as well as the salinity distribution due to the pumping of the wells on the groundwater coastal aquifer based on field investigation data and numerical modelling. Different well scenarios were used, such as the change in well abstraction rate, the different numbers of abstraction wells, the spacing between the abstraction wells and the change in screen depth in abstraction. The recommended scenarios were selected after comparing the predicted drawdown and salinity results for each scenario to minimize the seawater intrusion and preserve these resources from degradation.

scholarly journals Effects of Baekje Weir Operation on the Stream–Aquifer Interaction in the Geum River Basin, South Korea

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2984
Author(s):  
Hyeonju Lee ◽  
Min-Ho Koo ◽  
Byong Wook Cho ◽  
Yong Hwa Oh ◽  
Yongje Kim ◽  
...  
Keyword(s):  
South Korea ◽  
Groundwater Flow ◽  
Groundwater Quality ◽  
Flow System ◽  
Natural Ecosystem ◽  
Visual Modflow ◽  
Ecosystem Recovery ◽  
Groundwater Use ◽  
Groundwater Flow System ◽  
The Impact

Hydraulic structures have a significant impact on riverine environment, leading to changes in stream–aquifer interactions. In South Korea, 16 weirs were constructed in four major rivers, in 2012, to secure sufficient water resources, and some weirs operated periodically for natural ecosystem recovery from 2017. The changed groundwater flow system due to weir operation affected the groundwater level and quality, which also affected groundwater use. In this study, we analyzed the changes in the groundwater flow system near the Geum River during the Baekje weir operation using Visual MODFLOW Classic. Groundwater data from 34 observational wells were evaluated to analyze the impact of weir operation on stream–aquifer interactions. Accordingly, the groundwater discharge rates increased from 0.23 to 0.45 cm/day following the decrease in river levels owing to weir opening, while the hydrological condition changed from gaining to losing streams following weir closure. The variation in groundwater flow affected the groundwater quality during weir operation, changing the groundwater temperature and electrical conductivity (EC). Our results suggest that stream–aquifer interactions are significantly affected by weir operation, consequently, these repeated phenomena could influence the groundwater quality and groundwater use.

Simulation of Groundwater Flow and Pollutant Transport for Alluvial Aquifer in Kampung Tekek, Tioman Island

2012 ◽  
Author(s):  
Norhan Abd. Rahman ◽  
Woei–Keong Kuan
Keyword(s):  
Groundwater Flow ◽  
Flow Simulation ◽  
Pollutant Transport ◽  
World Health Organisation ◽  
Peninsular Malaysia ◽  
Tourism Industry ◽  
World Health ◽  
Visual Modflow ◽  
Transport Modelling ◽  
Potential Contaminant

Pulau Tioman terletak di pantai timur Semenanjung Malaysia. Akibat pembangunan yang pesat dalam industri pelancongan, permintaan terhadap bekalan air dijangka akan meningkat di pulau ini. Daripada kajian yang telah dijalankan sebelumnya, didapati airbumi merupakan sumber air yang berpotensi. Satu perisian model 3–dimensi (Visual MODFLOW) telah digunakan untuk menghasilkan model aliran airbumi dan pengangkutan bahan pencemar di Kampung Tekek dengan tujuan meramal simpanan airbumi dan penyebaran bahan pencemar, iaitu nitrat, semasa pengepaman. Daripada keputusan simulasi aliran airbumi yang diperolehi, pengepaman akuifer di Kampung Tekek dapat mencapai pada kadar 4000 m3/hari. Kajian model bahan pencemar menunjukkan kepekatan bahan pencemar nitrat yang tercatat di telaga pam didapati agak rendah dan memenuhi piawaian air minuman World Health Organisation (WHO). Kata kunci: Aliran airbumi, bahan pencemar, model numerik, Visual MODFLOW, pulau Tioman Island is situated in the east coast of Peninsular Malaysia. With rapid growth in tourism industry, the demand for water supply is expected to increase in this island. From previous studies, groundwater was found to be a potential source of water. A 3–dimensional numerical modelling software (Visual MODFLOW) is used to simulate the groundwater flow and pollutant transport of the aquifer in Kampung Tekek, for the prediction of available yield of groundwater, and also for studying the migration of potential contaminant source, i.e. nitrate, due to the withdrawal. The groundwater flow simulation results showed that the aquifer is capable of pumping 4000 m3/day. Results of pollutant transport modelling showed that the estimated concentration of nitrate in the pump well is generally low and complies with World Health Organisation (WHO) standard for drinking water. Key words: Groundwater flow, pollutant transport, numerical model, Visual MODFLOW, island

scholarly journals Simulation of Sub-Drains Performance Using Visual MODFLOW for Slope Water Seepage Problem

2016 ◽  
Vol 136 ◽  
pp. 012014 ◽  
Author(s):  
M F T Baharuddin ◽  
S A A Tajudin ◽  
M H Z Abidin ◽  
N A Yusoff
Keyword(s):  
Visual Modflow ◽  
Water Seepage ◽  
Seepage Problem

scholarly journals AVALIAÇÃO DO COMPORTAMENTO DE FRENTE DE CONTAMINAÇÃO EM FUNÇÃO DOS DIFERENTES VALORES DOS COEFICIENTES DE DISPERSIVIDADE

2005 ◽  
Vol 56 ◽  
Author(s):  
Janaina Barrios Palma ◽  
Lázaro Valentin Zuquette
Keyword(s):  
Minas Gerais ◽  
Visual Modflow ◽  
Poços De Caldas

Este trabalho apresenta os resultados obtidos por simulações numéricas utilizando o programa Visual Modflow para a área do lixão da cidade de Poços de Caldas (Estado de Minas Gerais, Brasil). Inicialmente, a área foi investigada e caracterizada em termos geológicos, geotécnicos, hidrogeológicos e climáticos. A partir destas características as escalas das heterogeneidades foram avaliadas e diferentes valores de coeficientes de dispersividade foram obtidos, e associados a tipos de fontes de poluentes em 11 cenários. Os resultados de cada simulação foram analisados frente aos dados obtidos por métodos geofísicos e trabalhos de campo. A simulação que considerou as menores diferenças entre valores de dispersividade vertical e horizontal para as diferentes camadas e os coeficientes de sorção segundo Langmuir foi a que apresentou melhor compatibilidade. Os valores de dispersividade longitudinal e das razões entre as dispersividades longitudinal, vertical e horizontal não afetaram, como esperado, as dimensões da frente de contaminação. Portanto as investigações geológico-geotécnicas possibilitam a avaliação do grau de heterogeneidade da área, e conseqüentemente a adoção de parâmetros de dispersividade muito adequados para a simulação de transporte de poluentes.

scholarly journals GROUNDWATER CONCEPTUAL MODEL FOR PADDY IRRIGATION

2015 ◽  
Vol 78 (1-2) ◽  
Author(s):  
Ahmad Fikri Abdullah ◽  
Wan Amirul Wan Mustapa
Keyword(s):  
Groundwater Flow ◽  
Conceptual Model ◽  
Root Zone ◽  
Groundwater Resources ◽  
Visual Modflow ◽  
Alternative Source ◽  
Aquifer Storage ◽  
Paddy Irrigation ◽  
Rice Irrigation ◽  
Current Water

Hydrological modelling is representative of current, past or future hydrologic balance. It has been used widely in water-related problem such as drought, flood, water contamination and irrigation. Crops irrigation requires a lot of water to irrigate the root zone layer especially for paddy crops. With the current issues of water such as drought and pollution, an alternative source is needed to overcome the problem of water scarcity.  Generally Malaysia depends on the surface water to irrigate the crops with no aided of groundwater. This study focuses on the availability of groundwater resources to irrigate the paddy crops. Hence, a conceptual model of groundwater flow was developed to shows the current situation of the groundwater flow at the study area. Several models were developed to see if groundwater can be extracted using wells and be used as an alternative source for irrigation. The study area is located at Sawah Sempadan, which is one of Malaysia’s greeneries areas under Tanjung Karang Rice Irrigation Scheme (TAKRIS). The conceptual model is built by using Visual MODFLOW 4.2. The conceptual model shows the current water balance, water table elevation and equipotential head in the study area. Simulations with pump wells have been done to shows the availability of groundwater sources for paddy irrigation. The result shows that groundwater flows from area of higher elevation towards the lower elevated area. It is also shows that groundwater extraction could not be too excessive as it may dry up the aquifer storage.

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