scholarly journals Hypothesis of Groundwater Flow through Geological Structures in Guarani Aquifer System (GAS) using Chemical and Isotopic Data

2017 ◽  
Vol 17 ◽  
pp. 136-139 ◽  
Author(s):  
Didier Gastmans ◽  
Andrés Mira ◽  
Roberto Kirchheim ◽  
Luis Vives ◽  
Letícia Rodríguez ◽  
...  
Keyword(s):  
Groundwater Flow ◽  
Isotopic Data ◽  
Geological Structures ◽  
Aquifer System ◽  
Guarani Aquifer ◽  
Flow Through

scholarly journals Regional Groundwater Modeling of the Guarani Aquifer System

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2323 ◽  
Author(s):  
Roger D. Gonçalves ◽  
Elias H. Teramoto ◽  
Hung K. Chang
Keyword(s):  
Water Balance ◽  
Groundwater Flow ◽  
Groundwater Recharge ◽  
Flow Model ◽  
Minor Amount ◽  
Groundwater Flow Model ◽  
Aquifer System ◽  
Gas System ◽  
Guarani Aquifer ◽  
Recharge Rates

The Guarani Aquifer System (GAS) is a strategic transboundary aquifer system shared by Brazil, Argentina, Paraguay and Uruguay. This article presents a groundwater flow model to assess the GAS system in terms of regional flow patterns, water balance and overall recharge. Despite the continental dimension of GAS, groundwater recharge is restricted to narrow outcrop zones. An important part is discharged into local watersheds, whereas a minor amount reaches the confined part. A three-dimensional finite element groundwater-flow model of the entire GAS system was constructed to obtain a better understanding of the prevailing flow dynamics and more reliable estimates of groundwater recharge. Our results show that recharge rates effectively contributing to the regional GAS water balance are only approximately 0.6 km3/year (about 4.9 mm/year). These rates are much smaller than previous estimates, including of deep recharge approximations commonly used for water resources management. Higher recharge rates were also not compatible with known 81Kr groundwater age estimates, as well as with calculated residence times using a particle tracking algorithm.

Hydrogeology and Simulation of Groundwater Flow in the Plymouth-Carver-Kingston-Duxbury Aquifer System, Southeastern Massachusetts

2009 ◽  
Author(s):  
John P. Masterson ◽  
Carl S. Carlson ◽  
Donald A. Walter ◽  
Gardner C. Other contributing authors: Bent ◽  
Andrew J. Massey
Keyword(s):  
Groundwater Flow ◽  
Aquifer System

scholarly journals Transboundary geophysical mapping of geological elements and salinity distribution critical for the assessment of future sea water intrusion in response to sea level rise

2012 ◽  
Vol 16 (7) ◽  
pp. 1845-1862 ◽  
Author(s):  
F. Jørgensen ◽  
W. Scheer ◽  
S. Thomsen ◽  
T. O. Sonnenborg ◽  
K. Hinsby ◽  
...  
Keyword(s):  
Groundwater Flow ◽  
Sea Level Rise ◽  
Sea Level ◽  
Preferential Flow ◽  
Sea Water ◽  
Saline Water ◽  
Seismic Survey ◽  
Salinity Distribution ◽  
Geological Structures ◽  
The North

Abstract. Geophysical techniques are increasingly being used as tools for characterising the subsurface, and they are generally required to develop subsurface models that properly delineate the distribution of aquifers and aquitards, salt/freshwater interfaces, and geological structures that affect groundwater flow. In a study area covering 730 km2 across the border between Germany and Denmark, a combination of an airborne electromagnetic survey (performed with the SkyTEM system), a high-resolution seismic survey and borehole logging has been used in an integrated mapping of important geological, physical and chemical features of the subsurface. The spacing between flight lines is 200–250 m which gives a total of about 3200 line km. About 38 km of seismic lines have been collected. Faults bordering a graben structure, buried tunnel valleys, glaciotectonic thrust complexes, marine clay units, and sand aquifers are all examples of geological structures mapped by the geophysical data that control groundwater flow and to some extent hydrochemistry. Additionally, the data provide an excellent picture of the salinity distribution in the area and thus provide important information on the salt/freshwater boundary and the chemical status of groundwater. Although the westernmost part of the study area along the North Sea coast is saturated with saline water and the TEM data therefore are strongly influenced by the increased electrical conductivity there, buried valleys and other geological elements are still revealed. The mapped salinity distribution indicates preferential flow paths through and along specific geological structures within the area. The effects of a future sea level rise on the groundwater system and groundwater chemistry are discussed with special emphasis on the importance of knowing the existence, distribution and geometry of the mapped geological elements, and their control on the groundwater salinity distribution is assessed.

scholarly journals National Sovereignty Versus Transboundary Water Cooperation: Can You See International Law Reflected in the Water?

AJIL Unbound ◽  
2021 ◽  
Vol 115 ◽  
pp. 178-182
Author(s):  
Francesco Sindico
Keyword(s):  
International Law ◽  
Transboundary Water ◽  
National Sovereignty ◽  
Customary International Law ◽  
Aquifer System ◽  
Water Cooperation ◽  
Guarani Aquifer ◽  
International Water Law ◽  
Downstream Flow ◽  
Transboundary Water Cooperation

Could Turkey dam the Tigris and Euphrates and deprive its downstream neighbors of vital water resources? Could Brazil over-pump the Guarani Aquifer System to the detriment of the other aquifer states? Could Egypt put pressure on upstream Nile states and prevent them from developing river related infrastructure that might limit downstream flow? International law in the field of transboundary water cooperation has evolved and would appear to condemn unilateral practices such as the ones suggested above. However, hydro politics and the lack of reception of international water law instruments by many countries sometimes make it difficult to see international law properly reflected in the management of major rivers, lakes and aquifers around the world. In this essay, I first highlight what international law dictates when it comes to the tension between national sovereignty and transboundary water cooperation. I then explore how this tension plays out in the three examples noted above. Due to limited acceptance of the existing international, bilateral, or regional legal instruments, the resolution of the tension between national sovereignty and transboundary water cooperation will often be left to customary international law.

scholarly journals Conceptual and Mathematical Modeling of a Coastal Aquifer in Eastern Delta of R. Nestos (N. Greece)

Hydrology ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 23
Author(s):  
Ioannis Gkiougkis ◽  
Christos Pouliaris ◽  
Fotios-Konstantinos Pliakas ◽  
Ioannis Diamantis ◽  
Andreas Kallioras
Keyword(s):  
Mathematical Modeling ◽  
Groundwater Flow ◽  
Coastal Aquifer ◽  
Flow Model ◽  
Meteorological Data ◽  
Field Measurements ◽  
Groundwater Flow Model ◽  
Aquifer System ◽  
Geophysical Surveys ◽  
The Mathematical Model

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.

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