scholarly journals Combining Groundwater Flow Modeling and Local Estimates of Extreme Groundwater Levels to Predict the Groundwater Surface with a Return Period of 100 Years

Geosciences ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 373
Author(s):  
Hans Kupfersberger ◽  
Gerhard Rock ◽  
Johannes C. Draxler

Knowledge about extreme groundwater levels is needed to avoid structural or environmental damage by groundwater flooding. Typically, distributions of extreme groundwater levels are generated by interpolation between results derived from local extreme value analysis at groundwater observation wells. As an alternative methodology, we propose to apply the Gumbel distribution to groundwater level time series, which are computed by a groundwater flow model. In the approach, model-based and observation-based extreme groundwater values are compared at every observation well using the model simulation period and the longest available observation period to calculate correction values that are regionalized over the model area. We demonstrate the applicability of the approach at the Südliches Wiener Becken (SWB) aquifer south of Vienna, where a groundwater flow model between 1993 to 2017 is available to compute the distribution of the groundwater levels with a hundred year return period (GLsWHYRP). We could show that the resulting GLsWHYRP are generally increased in regions of groundwater recharge and decreased in regions of groundwater discharge. The developed approach can also be used to assess the impact of changing boundary conditions on groundwater level and extreme highs and lows based on corresponding model scenarios.

Water Policy ◽  
2016 ◽  
Vol 18 (5) ◽  
pp. 1139-1154 ◽  
Author(s):  
Xiaolong Li ◽  
Xinlin He ◽  
Guang Yang ◽  
Li Zhao ◽  
Si Chen ◽  
...  

For effective groundwater management of a basin, it is essential that a careful water balance study be carried out. A three-dimensional transient-state finite difference groundwater flow model is used to quantify the groundwater fluxes and analyze the dynamic changes of groundwater level. After monitoring groundwater levels for 43 typical observation wells through a simulation study of the groundwater flow model with a depth of 300 m, results reveal that the study area has a lateral recharge of about 3.57 × 109 m3, which makes up 79.08% of the total recharge; total evaporation is about 1.81 × 108 m3, which makes up 3.77% of the total discharge. The balance of groundwater is negative, with a recharge and discharge difference of −2.81 × 108 m3. The correlation coefficient between the observed head and the calculated head for the simulation period is greater than 0.81, indicating the simulation results are satisfactory. The maximum groundwater drawdown is 26.59 m and the rate of the groundwater drawdown is 0.15 m/d during normal operation of the pumping well.


2021 ◽  
Vol 3 (7) ◽  
Author(s):  
Meriem Lghoul ◽  
Karim Sbihi ◽  
Abdelkabir Maqsoud ◽  
Rachid Hakkou ◽  
Azzouz Kchikach

AbstractIn this study, we present the efficiency of remediation scenario to attenuate the impact of acid mine drainage (AMD) contamination in the Kettara abandoned mine site. The study focuses on the AMD groundwater contamination of the Sarhlef shists aquifer. To predict the evolution of AMD groundwater contamination in the Kettara mine site under remediation scenario, a model of groundwater flow and AMD transport was performed.Piezometric heads were measured at the dry and wet periods from eleven wells located downstream of mine wastes. To elaborate a conceptual groundwater flow model, we faced with to the heterogeneity and anisotropy of fractured Sarhlef shists aquifer. Consequently, the study focused on the use of various approaches: 1. The inverse modeling by the CMA-ES algorithm is adopted as an alternative approach to determine hydraulic parameters indirectly, and 2. the model is treated as an equivalent porous media (EPM). The groundwater flow model was carried out in steady-state and transient conditions in the dry and wet periods using the PMWIN interface. The obtained results are satisfactory and show an excellent correlation between measured and computed heads. Contaminant transport model is used to solve the advection–dispersion equation and to generate the AMD concentration by MT3D via the PMWIN interface. A sensitivity analysis of the dispersivity coefficient is carried out. The AMD transport simulation was computed during periods of 1, 5 and 10 years, and the performed model indicates that the simulated concentrations under remediation scenario are reduced 1000 times comparing to the current concentrations. The study revealed a necessary approach in addressing an environmental issue for the AMD contamination. The results of the study will be a start-up for further research work in the study area and implementing it for the prevention of AMD propagation plume.


Hydrology ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 23
Author(s):  
Ioannis Gkiougkis ◽  
Christos Pouliaris ◽  
Fotios-Konstantinos Pliakas ◽  
Ioannis Diamantis ◽  
Andreas Kallioras

In this paper, the development of the conceptual and groundwater flow model for the coastal aquifer system of the alluvial plain of River Nestos (N. Greece), that suffers from seawater intrusion due to over-pumping for irrigation, is analyzed. The study area is a typical semi-arid hydrogeologic environment, composed of a multi-layer granular aquifers that covers the eastern coastal delta system of R. Nestos. This study demonstrates the results of a series of field measurements (such as geophysical surveys, hydrochemical and isotopical measurements, hydro-meteorological data, land use, irrigation schemes) that were conducted during the period 2009 to 2014. The synthesis of the above resulted in the development of the conceptual model for this aquifer system, that formed the basis for the application of the mathematical model for simulating groundwater flow. The mathematical modeling was achieved using the finite difference method after the application of the USGS code MODFLOW-2005.


Author(s):  
Samrit Luoma ◽  
Juha Majaniemi ◽  
Arto Pullinen ◽  
Juha Mursu ◽  
Joonas J. Virtasalo

AbstractThree-dimensional geological and groundwater flow models of a submarine groundwater discharge (SGD) site at Hanko (Finland), in the northern Baltic Sea, have been developed to provide a geological framework and a tool for the estimation of SGD rates into the coastal sea. The dataset used consists of gravimetric, ground-penetrating radar and shallow seismic surveys, drill logs, groundwater level monitoring data, field observations, and a LiDAR digital elevation model. The geological model is constrained by the local geometry of late Pleistocene and Holocene deposits, including till, glacial coarse-grained and fine-grained sediments, post-glacial mud, and coarse-grained littoral and aeolian deposits. The coarse-grained aquifer sediments form a shallow shore platform that extends approximately 100–250 m offshore, where the unit slopes steeply seawards and becomes covered by glacial and post-glacial muds. Groundwater flow preferentially takes place in channel-fill outwash coarse-grained sediments and sand and gravel interbeds that provide conduits of higher hydraulic conductivity, and have led to the formation of pockmarks on the seafloor in areas of thin or absent mud cover. The groundwater flow model estimated the average SGD rate per square meter of the seafloor at 0.22 cm day−1 in autumn 2017. The average SGD rate increased to 0.28 cm day−1 as a response to an approximately 30% increase in recharge in spring 2020. Sensitivity analysis shows that recharge has a larger influence on SGD rate compared with aquifer hydraulic conductivity and the seafloor conductance. An increase in recharge in this region will cause more SGD into the Baltic Sea.


2018 ◽  
Vol 7 (1) ◽  
pp. 22 ◽  
Author(s):  
Muhammad Usman ◽  
Thomas Reimann ◽  
Rudolf Liedl ◽  
Azhar Abbas ◽  
Christopher Conrad ◽  
...  

2021 ◽  
pp. 91-97
Author(s):  
V. V. Suskin ◽  
A. V. Rastorguev ◽  
I. V. Kapyrin

This article discusses a three-dimensional groundwater flow model of a deep disposal facility at Severny test site. The three-dimensional model is a part of the certified software GEOPOLIS, based on the hydrogeological code GeRa (Geomigration of Radionuclides) serving as the calculation engine. This study describes the hydrogeological patterning of the groundwater flow model, as well as the results of calibration and verification of the model water heads with respect to the data of monitoring for more than 40 years of the deep repository exploitation. The article begins with a brief overview of the previously developed hydrogeological models of this object and continues with a description of the geological structure of the territory, and with a substantiation of the boundaries and parameters of the model. The results of groundwater flow modeling, model calibration, verification and estimation of discrepancy between the model results and monitoring data are shown. The comparison of the modeled and observed water heads in the stationary conditions (before the start of injection) and during operation of the deep repository allows making conclusion on the quality of calibration.


1992 ◽  
Vol 29 (4) ◽  
pp. 696-701
Author(s):  
Denis Isabel ◽  
Pierre Gélinas ◽  
Jacques Locat

The groundwater pollution case at Mercier is a very complex one. Groundwater flow modeling has been a valuable tool in the assessment of this large environmental problem. However, due to the complexity of the hydrogeological setting, the modeling has been performed with various simple case models in lieu of a large complex model. Here we report the results of one of these piecewise modeling tasks that proved very useful in the explanation of the strong upward gradients observed in the bedrock aquifer. These results and their interpretation prove the usefulness of the piecewise modeling strategy in this case. Key words : ground water modeling, finite elements.


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