Quantitative estimation of submarine groundwater discharge using airborne thermal infrared data acquired at two different tidal heights

Submarine Groundwater Discharge (SGD) represents a significant mode of chemical transport to water bodies, making it an important flux to understand. Small Unmanned Aircraft Systems-deployed thermal infrared sensors (sUAS-TIR) provide a financially and logistically inexpensive means of identifying SGD source zones and quantifying SGD thermal infrared (TIR) plume areas over regional scales at high spatial resolutions. sUAS-TIR additionally offers the unique capability of high temporal resolution measurements of SGD. As a developing science application, the use of sUAS-TIR to image SGD requires substantial background knowledge. We present a proposed methodological construct for implementing a sUAS-TIR program for SGD-TIR data gathering, with applications extending to other research fields that can benefit from airborne TIR. Several studies have used airborne TIR in combination with empirical SGD flux measurements to quantify SGD, reporting a consistently strong regression between SGD flux and SGD TIR plume area. We additionally discuss novel research opportunities for sUAS-TIR technologies, as applied to SGD flux. The combination of high spatial and temporal resolution capabilities, at relatively low costs, make sUAS-TIR a promising new technology to overcome the scaling challenges presented by empirical studies and modeling of SGD fluxes, and advance our understanding of the controls on SGD fluxes.

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Applicability of Landsat 8 Thermal Infrared Sensor to Identify Submarine Groundwater Discharge Springs in the Mediterranean Sea Basin

10.5194/hess-2020-569 ◽

2020 ◽

Author(s):

Sònia Jou-Claus ◽

Albert Folch ◽

Jordi Garcia-Orellana

Keyword(s):

Mediterranean Sea ◽

Submarine Groundwater Discharge ◽

Regional Scale ◽

Groundwater Discharge ◽

Thermal Infrared ◽

Landsat 8 ◽

Infrared Sensor ◽

Hydrogeological Characteristics ◽

Submarine Groundwater ◽

The Mediterranean

Abstract. Submarine groundwater discharge (SGD) has received increasing attention over the past two decades as a source of nutrients, trace elements and pollutants to the ocean that may alter coastal biogeochemical cycles. Assessing submarine groundwater flows and their impacts on coastal marine environments is a difficult task since it is not easy to identify and measure these water flows discharging into the sea. The aim of this study is to prove the great usefulness of the freely-available thermal infrared (TIR) imagery of the Landsat 8 thermal infrared sensor (TIRS) as an exploratory tool to identify SGD springs worldwide, from local to regional scales, for long-term analysis. The use of satellite thermal data as a technique to identify SGD springs in seawater is based on the identification of thermally-anomalous plumes obtained from the thermal contrasts between groundwater and sea surface water. We propose a conceptual framework to apply this technique worldwide and also discuss the limitations of using this technique in SGD studies. The study was developed on a regional scale in karstic coastal aquifers in the Mediterranean Sea basin at different seasons and diverse meteorological conditions. Although this study demonstrates that the freely-available satellite TIR remote sensing is a useful method to identify coastal springs in karst aquifers both locally and regionally, the limiting factors include technical limitations, geological/hydrogeological characteristics, environmental and marine conditions and coastal geomorphology.

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Using Thermal Infrared Imagery (TIR) for Illustrating the Submarine Groundwater Discharge into the Eastern Shoreline of the Dead Sea-Jordan

American Journal of Environmental Sciences ◽

10.3844/ajessp.2008.693.700 ◽

2008 ◽

Vol 4 (6) ◽

pp. 693-700 ◽

Cited By ~ 11

Author(s):

Emad Akawwi ◽

Abdallah Al-Zouabi ◽

Maher Kakish ◽

Fredrich Koehn ◽

Martin Sauter

Keyword(s):

Submarine Groundwater Discharge ◽

Groundwater Discharge ◽

Thermal Infrared ◽

Dead Sea ◽

Infrared Imagery ◽

Submarine Groundwater ◽

The Dead ◽

Thermal Infrared Imagery

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Investigation of Submarine Groundwater Discharge using Thermal Satellite and Radon mapping along the East Coast of the Tamil Nadu and Pondicherry Region, India

International Journal of Civil, Environmental and Agricultural Engineering ◽

10.34256/10.34256/ijceae2111 ◽

2021 ◽

pp. 1-18

Author(s):

Rajesh Kanna A ◽

Srinivasamoorthy K ◽

Ponnumani G ◽

Babu C ◽

Prakash R ◽

...

Keyword(s):

Submarine Groundwater Discharge ◽

Tamil Nadu ◽

Hydrological Cycle ◽

Chemical Constituents ◽

Groundwater Discharge ◽

Thermal Infrared ◽

Landsat 8 ◽

Infrared Images ◽

Thermal Infrared Images ◽

Submarine Groundwater

Submarine groundwater discharge (SGD) demarcated as a significant component of hydrological cycle found to discharge greater volumes of terrestrial fresh and recirculated seawater to the ocean associated with chemical constituents (nutrients, metals, and organic compounds) aided by downward hydraulic gradient and sediment-water exchange. Delineating SGD is of primal significance due to the transport of nutrients and contaminants due to domestic, industrial, and agricultural practices that influence the coastal water quality, ecosystems, and geochemical cycles. An attempt has been made to demarcate the SGD using thermal infrared images and radon-222 (222Rn) isotope. Thermal infrared images processed from LANDSAT-8 data suggest prominent freshwater fluxes with higher temperature anomalies noted in Cuddalore and Nagapattinam districts, and lower temperature noted along northern and southern parts of the study area suggest saline/recirculated discharge. Groundwater samples were collected along the coastal regions to analyze Radon and Physico-chemical constituents. Radon in groundwater ranges between 127.39 Bq m-3 and 2643.41 Bq m-3 with an average of 767.80 Bq m-3. Calculated SGD fluxes range between -1.0 to 26.5 with an average of 10.32 m day-1. Comparison of the thermal infrared image with physio-chemical parameters and Radon suggest fresh, terrestrial SGD fluxes confined to the central parts of the study area and lower fluxes observed along with the northern and southern parts of the study area advocate impact due to seawater intrusion and recirculated seawater influence.

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