Salinity Contributions from Geothermal Waters to the Rio Grande and Shallow Aquifer System in the Transboundary Mesilla (United States)/Conejos-Médanos (Mexico) Basin

Freshwater scarcity has raised concerns about the long-term availability of the water supplies within the transboundary Mesilla (United States)/Conejos-Médanos (Mexico) Basin in Texas, New Mexico, and Chihuahua. Analysis of legacy temperature data and groundwater flux estimates indicates that the region’s known geothermal systems may contribute more than 45,000 tons of dissolved solids per year to the shallow aquifer system, with around 8500 tons of dissolved solids being delivered from localized groundwater upflow zones within those geothermal systems. If this salinity flux is steady and eventually flows into the Rio Grande, it could account for 22% of the typical average annual cumulative Rio Grande salinity that leaves the basin each year—this salinity proportion could be much greater in times of low streamflow. Regional water level mapping indicates upwelling brackish waters flow towards the Rio Grande and the southern part of the Mesilla portion of the basin with some water intercepted by wells in Las Cruces and northern Chihuahua. Upwelling waters ascend from depths greater than 1 km with focused flow along fault zones, uplifted bedrock, and/or fractured igneous intrusions. Overall, this work demonstrates the utility of using heat as a groundwater tracer to identify salinity sources and further informs stakeholders on the presence of several brackish upflow zones that could notably degrade the quality of international water supplies in this developed drought-stricken region.

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Effects of multi-annual climate variability on the hydrodynamic evolution (1833 to present) in a shallow aquifer system in northern Belgium

Hydrological Sciences Journal ◽

10.1080/02626667.2010.488075 ◽

2010 ◽

Vol 55 (5) ◽

pp. 763-779 ◽

Cited By ~ 3

Author(s):

Marc Van Camp ◽

Marleen Coetsiers ◽

Kristine Martens ◽

Kristine Walraevens

Keyword(s):

Climate Variability ◽

Shallow Aquifer ◽

Aquifer System ◽

Hydrodynamic Evolution ◽

Shallow Aquifer System

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Hydrogeological effects of dredging navigable canals through lagoon shallows. A case study in Venice

Hydrology and Earth System Sciences ◽

10.5194/hess-21-5627-2017 ◽

2017 ◽

Vol 21 (11) ◽

pp. 5627-5646 ◽

Cited By ~ 7

Author(s):

Pietro Teatini ◽

Giovanni Isotton ◽

Stefano Nardean ◽

Massimiliano Ferronato ◽

Annamaria Mazzia ◽

...

Keyword(s):

Fluid Dynamic ◽

Industrial Area ◽

Venice Lagoon ◽

Shallow Aquifer ◽

Aquifer System ◽

Cfd Models ◽

Ship Wakes ◽

Ecotoxicity Testing ◽

Set Up ◽

Shallow Aquifer System

Abstract. For the first time a comprehensive investigation has been carried out to quantify the possible effects of dredging a navigable canal on the hydrogeological system underlying a coastal lagoon. The study is focused on the Venice Lagoon, Italy, where the port authority is planning to open a new 10 m deep and 3 km long canal to connect the city passenger terminal to the central lagoon inlet, thus avoiding the passage of large cruise ships through the historic center of Venice. A modeling study has been developed to evaluate the short (minutes), medium (months), and long (decades) term processes of water and pollutant exchange between the shallow aquifer system and the lagoon, possibly enhanced by the canal excavation, and ship wakes. An in-depth characterization of the lagoon subsurface along the channel has supported the numerical modeling. Piezometer and sea level records, geophysical acquisitions, laboratory analyses of groundwater and sediment samples (chemical analyses and ecotoxicity testing), and the outcome of 3-D hydrodynamic and computational fluid dynamic (CFD) models have been used to set up and calibrate the subsurface multi-model approach. The numerical outcomes allow us to quantify the groundwater volume and estimate the mass of anthropogenic contaminants (As, Cd, Cu, Cr, Hg, Pb, Se) likely leaked from the nearby industrial area over the past decades, and released into the lagoon from the canal bed by the action of depression waves generated by ships. Moreover, the model outcomes help to understand the effect of the hydrogeological layering on the propagation of the tidal fluctuation and salt concentration into the shallow brackish aquifers underlying the lagoon bottom.

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