scholarly journals Submarine Groundwater Discharge From Sediments and Sand Boils Quantified by the Mean Residence Time of a Tracer Injection

2021 ◽  
Vol 9 ◽  
Author(s):  
Michael Schlüter ◽  
Philipp Maier
Keyword(s):  
Residence Time ◽  
Mean Residence Time ◽  
Submarine Groundwater Discharge ◽  
Groundwater Discharge ◽  
Tracer Injection ◽  
Discharge Rates ◽  
Seepage Meter ◽  
Submarine Groundwater ◽  
Sand Boils ◽  
The Mean

To quantify submarine groundwater discharge, we developed an inexpensive automated seepage meter that applies a tracer injection and the computation of the mean residence time. The SGD-MRT is designed to measure a wide range of discharge rates from about 30 to 800 cm³/min and allows minimizing backpressures caused by pipe friction or flow sensors. By modifying the inner volume of the flow-through unit, the range of measurement is adjustable to lower or higher discharge rates. For process control and data acquisition, an Arduino controller board is used. In addition, components like temperature, conductivity, and pressure sensors or pumps extend the scope of the seepage meter. During field tests in the Wadden Sea, covering tidal cycles, discharge rates of more than 700 cm³/min were released from sand boils. Based on the measured discharge rates and numerical integration of the time series data, a water volume of about 400 dm3 with a seawater content of less than 12% was released from the sand boil within 7 h.

Geochemical tracers in submarine groundwater discharge research: practice and challenges from a view of climate changes

2020 ◽  
Author(s):  
Shan Jiang ◽  
Juan Severino Pino Ibánhez ◽  
Ying Wu ◽  
Jing Zhang
Keyword(s):  
Submarine Groundwater Discharge ◽  
Climate Changes ◽  
Groundwater Discharge ◽  
Economic Losses ◽  
Geochemical Tracers ◽  
Algae Blooms ◽  
Discharge Rates ◽  
Submarine Groundwater ◽  
Application Requirements ◽  
Temperature Water

Submarine groundwater discharge (SGD), the flux of porewater from permeable seabed or karst conduits to surface water bodies delivers a significant quantity of land-borne solutes to coastal oceans. This input of land-derived solutes is frequently linked with eutrophication, harmful algae blooms and benthic hypoxia, and hence has the potential to trigger great economic losses. Geophysical and geochemical tracers, including salinity, temperature, water stable isotopes and radioactive elements, have been widely applied in SGD studies for more than 50 years in order to, amongst others, identify water sources, estimate residence times and quantify discharge rates. Here we review advantages and shortcomings of these tracers in the study of SGD. Application requirements are outlined based on previous research and combined tracer approaches in karst environments, permeable coasts and estuaries are illustrated under the view of climate changes. Current challenges with the use of geochemical tracers in SGD studies are highlighted and opportunities to develop these tracers for improved coastal management showcased.

scholarly journals Submarine Groundwater Discharge in a Coastal Bay: Evidence from Radon Investigations

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2552
Author(s):  
Manhua Luo ◽  
Yan Zhang ◽  
Hailong Li ◽  
Xuejing Wang ◽  
Kai Xiao
Keyword(s):  
Submarine Groundwater Discharge ◽  
Anthropogenic Activities ◽  
Jiaozhou Bay ◽  
Groundwater Discharge ◽  
Dry Season ◽  
Balance Model ◽  
Wet Season ◽  
Discharge Rates ◽  
Submarine Groundwater ◽  
Coastal Bay

Jiaozhou Bay, an urbanized coastal bay located in the southern part of Shandong Peninsula, China, has been deeply affected by anthropogenic activities. Here, the naturally occurring 222Rn isotope was used as a tracer to assess the submarine groundwater discharge (SGD) in this bay. The time series of 222Rn concentrations in nearshore seawater were monitored continuously over several tidal cycles at two fixed sites (Tuandao (TD) and Hongdao (HD)) during the dry season in spring and the wet season in autumn of 2016. 222Rn concentrations in seawater were negatively related to the water depth, indicating the influence of tidal pumping. A 222Rn mass balance model revealed that the mean SGD rates were 21.9 cm/d at TD and 17.8 cm/d at HD in the dry season, and were 19.5 cm/d at TD and 26.9 cm/d at HD in the wet season. These rates were about 8–14 times the discharge rates of the local rivers. Enhanced groundwater inputs occurred at HD in the wet season, likely due to the large tidal amplitudes and the rapid response to local precipitation. Large inputs of SGD may have important influences on nutrients levels and structure, as well as the water eutrophication occurring in coastal waters.

scholarly journals SUBMARINE GROUNDWATER DISCHARGE MEASUREMENT ON THE SANDY UNCONFINED AQUIFER AT THE CARNAVAL BEACH, ANCOL (JAKARTA BAY)

2017 ◽  
Vol 41 (2) ◽  
pp. 59-65
Author(s):  
Hendra Bakti ◽  
Rachmat Fajar Lubis ◽  
Robert M. Delinom ◽  
Makoto Taniguchi
Keyword(s):  
Fresh Water ◽  
Coastal Waters ◽  
Submarine Groundwater Discharge ◽  
Groundwater Discharge ◽  
Unconfined Aquifer ◽  
Groundwater System ◽  
Seepage Meter ◽  
Submarine Groundwater ◽  
Direct Discharge ◽  
Temperature Depth

Submarine groundwater discharge (SGD) is defined as all direct discharge of subsurface fluids into coastal zone. Components of SGD consist of fresh submarine groundwater discharge and the recirculated saline seawater discharge. SGD could act as a pathway for the transport of anthropogenic contaminants and nutrients to coastal waters. Measurement SGD at Carnaval Beach, Ancol, Jakarta was focussed on unconfined groundwater system. The method of quantified used automatic seepage meter for measured of SGD and installed conductivity temperature depth. The average SGD rate was 0.21 mm/min on March 20-31, 2009 consist of 19.05% fresh water, 80.95% recirculated seawater. April 1-23, 2009, the average SGD rate was 0.81 ml/min which consisted of 16.04% fresh water, 83.96% recirculated seawater. SGD fluctuation was opposite with the tide. As a result, submarine groundwater discharge at Jakarta coastal area was defined and can be measured to quantify.

Estimation of coastal residence time of submarine groundwater discharge using radium progenies

2017 ◽  
Vol 121 ◽  
pp. 44-50 ◽  
Author(s):  
G. Eleftheriou ◽  
C. Tsabaris ◽  
D.L. Patiris ◽  
E.G. Androulakaki ◽  
R. Vlastou
Keyword(s):  
Residence Time ◽  
Submarine Groundwater Discharge ◽  
Groundwater Discharge ◽  
Submarine Groundwater

scholarly journals Multi-scale evaluations of submarine groundwater discharge

2015 ◽  
Vol 365 ◽  
pp. 66-71 ◽  
Author(s):  
M. Taniguchi ◽  
M. Ono ◽  
M. Takahashi
Keyword(s):  
Submarine Groundwater Discharge ◽  
Groundwater Discharge ◽  
Daily Basis ◽  
Sea Level Changes ◽  
Point Scale ◽  
Multi Scale ◽  
Seepage Meters ◽  
Seepage Meter ◽  
Submarine Groundwater ◽  
Made In

Abstract. Multi-scale evaluations of submarine groundwater discharge (SGD) have been made in Saijo, Ehime Prefecture, Shikoku Island, Japan, by using seepage meters for point scale, 222Rn tracer for point and coastal scales, and a numerical groundwater model (SEAWAT) for coastal and basin scales. Daily basis temporal changes in SGD are evaluated by continuous seepage meter and 222Rn mooring measurements, and depend on sea level changes. Spatial evaluations of SGD were also made by 222Rn along the coast in July 2010 and November 2011. The area with larger 222Rn concentration during both seasons agreed well with the area with larger SGD calculated by 3D groundwater numerical simulations.

Sign in / Sign up

Export Citation Format

Share Document