scholarly journals Measuring stream discharge to infer the spatial distribution of groundwater discharge

1995 ◽  
Author(s):  
M J Hinton
2019 ◽  
Author(s):  
◽  
Hajar Al Balushi

The inflow of fresh or brackish groundwater into the sea is referred to as Submarine Groundwater Discharge (SGD). The SGD is enforced by a terrestrial component whichmainly depends on freshwater extraction and recharge by meteoric water and on aquifer permeability. And a marine component that is mainly controlled by the spatial distribution of outflows and water depth (hydraulic gradients between land and sea). This study is motivated by the importance of freshwater in arid regions and, in particular, by the continuous challenges posed by the exploration and exploitation of fresh water sources inthe Sultanate of Oman. Moreover, there is a lack of studies on SGD phenomena alongthe 1000 km coastline in the South of Oman. The objective of this study is to develop a method to detect SGD spots in the offshore region, autonomously, and understanding thehydrodynamics of the discharge seepage for future backtracking, quantification and coastaland groundwater management. The study area Salalah, Dhofar Governorate, South of Oman is known to have a high natural groundwater recharge during the monsoon seasonand a karstic coastal seafloor, which results in a high potential of submarine groundwater discharge spots.


2006 ◽  
Vol 33 (6) ◽  
Author(s):  
Makoto Taniguchi ◽  
Tomotoshi Ishitobi ◽  
Jun Shimada ◽  
Naohiko Takamoto

2021 ◽  
Vol 18 (7) ◽  
pp. 2325-2345
Author(s):  
Petra Zahajská ◽  
Carolina Olid ◽  
Johanna Stadmark ◽  
Sherilyn C. Fritz ◽  
Sophie Opfergelt ◽  
...  

Abstract. High biogenic silica (BSi) concentrations occur sporadically in lake sediments throughout the world; however, the processes leading to high BSi concentrations vary. We explored the factors responsible for the high BSi concentration in sediments of a small, high-latitude subarctic lake (Lake 850). The Si budget of this lake had not been fully characterized before to establish the drivers of BSi accumulation in this environment. To do this, we combined measurements of variations in stream discharge, dissolved silica (DSi) concentrations, and stable Si isotopes in both lake and stream water with measurements of BSi content in lake sediments. Water, radon, and Si mass balances revealed the importance of groundwater discharge as a main source of DSi to the lake, with groundwater-derived DSi inputs 3 times higher than those from ephemeral stream inlets. After including all external DSi sources (i.e., inlets and groundwater discharge) and estimating the total BSi accumulation in the sediment, we show that diatom production consumes up to 79 % of total DSi input. Additionally, low sediment accumulation rates were observed based on the dated gravity core. Our findings thus demonstrate that groundwater discharge and low mass accumulation rate can account for the high BSi accumulation during the last 150 cal yr BP. Globally, lakes have been estimated to retain one-fifth of the annual DSi terrestrial weathering flux that would otherwise be delivered to the ocean. Well-constrained lake mass balances, such as presented here, bring clarity to those estimates of the terrestrial Si cycle sinks.


2019 ◽  
Vol 31 (6) ◽  
pp. 1749-1757
Author(s):  
SU Weigang ◽  
◽  
SHA Zhanjiang ◽  
KONG Fancui ◽  
WANG Qiugui ◽  
...  

2004 ◽  
Vol 49 (1) ◽  
pp. 157-167 ◽  
Author(s):  
Michael Schlüter ◽  
Eberhard J. Sauter ◽  
Claus E. Andersen ◽  
Henning Dahlgaard ◽  
Paul R. Dando

2021 ◽  
Author(s):  
Nataline Simon ◽  
Olivier Bour ◽  
Mikaël Faucheux ◽  
Nicolas Lavenant ◽  
Hugo Le Lay ◽  
...  

Abstract. FO-DTS (Fiber Optic Distributed Temperature Sensing) technology has been widely developed to quantify exchanges between groundwater and surface water during the last decade. In this study, we propose, for the first time, to combine long-term passive-DTS measurements and active-DTS measurements in order to highlight their respective potential to locate and quantify groundwater discharge into streams. On the one hand, passive-DTS measurements consist in monitoring natural temperature fluctuations to detect and localize groundwater inflows and characterize the temporal pattern of exchanges. Although easy to set up, the quantification of fluxes with this approach often remains difficult since it relies on energy balance models or on the coupling of distributed temperature measurements with additional punctual measurements. On the other hand, active-DTS methods, recently developed in hydrogeology, consist in continuously monitoring temperature changes induced by a heat source along a FO cable. Recent developments showed that this approach, although more complex to set up than passive-DTS measurements, can address the challenge of quantifying groundwater fluxes and their spatial distribution. Yet it has almost never been conducted in streambed sediments. In this study, both methods are combined by deploying FO cables in the streambed sediments of a first- and second-order stream within a small agricultural watershed. A numerical model is used to interpret passive-DTS measurements and highlight the temporal and spatial dynamic of groundwater discharge over the annual hydrological cycle. We underline the difficulties and the limitations of deploying a single FO cable to investigate groundwater discharge and show the impact of uncertainty on sediments thermal properties on the quantification of groundwater inflows. On the opposite, the active-DTS experiment allows estimating the spatial distribution of both the thermal conductivity and the groundwater flux at high resolution with very low uncertainties all along the heated section of FO cable. Our results highlight the added values of conducting active-DTS experiments, eventually combined with passive-DTS measurements, to fully investigate and characterize patterns of groundwater-stream water exchanges at the stream scale. The combination of both methods allows discussing the impact of topography and hydraulic conductivity variations on the variability of groundwater inflows in headwater catchments.


2012 ◽  
Vol 46 (10) ◽  
pp. 5319-5326 ◽  
Author(s):  
Takahiro Hosono ◽  
Masahiko Ono ◽  
William C. Burnett ◽  
Takahiro Tokunaga ◽  
Makoto Taniguchi ◽  
...  

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