Thermal infrared imaging for the detection of relatively warm lacustrine groundwater discharge at the surface of freshwater bodies

Abstract

Thermal infrared (TIR) imaging has been previously applied to survey relatively large thermal footprints in coastal zones, lakes, reservoirs and rivers. In freshwater systems, the buoyancy of relatively warm groundwater during the winter months allows for the surface identification of groundwater discharge or thermal pollution using TIR imaging. However, information regarding the performance of TIR for resolving this warm groundwater upwelling is limited, particularly at fine spatial scales and variable discharge rates. In order to evaluate the suitability of TIR to trace warm groundwater upwelling at the water surface of lakes, ponds and reservoirs (e.g. lacustrine groundwater discharge (LGD) in shallow near-shore zones) we conducted a mesocosm experiment with a TIR camera situated 4 m above the water surface to capture thermal patterns in response to different groundwater discharge rates, weather conditions and the diurnal cycle. A fiber optic distributed temperature sensing system (FO-DTS) installed at 2 cm below the water surface was used to ground-truth spatial patterns observed in TIR images. Results show the impacts of both the diurnal cycle of net radiation and prevailing weather conditions on the accuracy of TIR imaging for resolving warm groundwater discharge. Most reliable results were obtained under overcast weather conditions and during the night. The results of our study provide guidance for those looking to use TIR for conducting thermal tracing of LGD at the surface of freshwater bodies during winter.

Scrutinizing Relationships between Submarine Groundwater Discharge and Upstream Areas Using Thermal Remote Sensing: A Case Study in the Northern Persian Gulf

“…Sass et al [25] detected terrestrial groundwater discharge zones with Landsat TIR data from Alberta, Canada. Arricibita et al [26], who used a TIR camera in a laboratory experiment, indicated that analysis of TIR data allows for the measurement of water surface temperature at high spatial resolution across a wide range of scales. Thus, TIR remote sensing can be applied to assess SGD and extrapolate local groundwater fluxes to a regional scale and, therefore, potentially reduce the amount of field sampling and in situ measurements required.…”

Advancing measurements and representations of subsurface heterogeneity and dynamic processes: towards 4D hydrogeology

“…The use of heat as a natural tracer has become a popular tool to characterize GW-SW exchange patterns due to the natural temperature differences between GW and SW and the relative ease and accuracy of temperature measurements using standard sensors. This field has evolved significantly since some of the earlier seminal works (Stonestrom and Constantz, 2003;Schmidt et al, 2006) and has embraced novel technologies such as DTS (Krause et al, 2012;Rose et al, 2013) and hand-held (Glaser et al, 2016;Marruedo Arricibita et al, 2018) or airborne infrared imagery (Lewandowski et al, 2013). The suite of methods available today allows for high-resolution assessment of temperatures in space and time for a qualitative mapping of GW-SW exchange patterns (Anibas et al, 2011;Krause et al, 2012) or a quantification of exchange fluxes (Schornberg et al, 2010;.…”

Looking to the Skies: Realising the Combined Potential of Drones and Thermal Infrared Imagery to Advance Hydrological Process Understanding in Headwaters

“…In particular, high resolution thermal infrared (TIR) imaging has been increasingly used to quantify hydrological states through the use of temperature as a “tracer” or “signature” for (near‐) surface flow and saturation (Glaser et al., 2018). Hydrologists have used ground‐based TIR for characterizing groundwater‐surface water (GW‐SW) interactions in 2D (e.g., Briggs et al., 2013; Deitchman & Loheide, 2009; Drake et al., 2010; Hare et al., 2015; Lu et al., 2020; Pandey et al., 2013; Schuetz & Weiler, 2011), describing hydraulic processes such as surface flow velocity or mixing across the stream channel (e.g., Antonelli et al., 2017; Puleo et al., 2012) and understanding surface water energy budgets or thermal heterogeneity (e.g., Baker et al., 2019; Cardenas et al., 2014; Marruedo Arricibita et al., 2018; Tonolla et al., 2010). Ground‐based TIR has also been increasingly deployed for mapping surface saturation (e.g., Antonelli et al., 2020; Glaser et al., 2018; Glaser et al., 2020; Glaser et al., 2016; Pfister et al., 2010; Figures 1a and 1b).…”