Uncertainty assessment of quantifying spatially concentrated groundwater discharge to small streams by distributed temperature sensing

2013 ◽  
Vol 49 (1) ◽  
pp. 400-407 ◽  
Author(s):  
Florian Lauer ◽  
Hans-Georg Frede ◽  
Lutz Breuer
Keyword(s):  
Groundwater Discharge ◽  
Uncertainty Assessment ◽  
Temperature Sensing ◽  
Distributed Temperature Sensing ◽  
Small Streams

scholarly journals Upscaling lacustrine groundwater discharge rates by fiber-optic distributed temperature sensing

2013 ◽  
Vol 49 (12) ◽  
pp. 7929-7944 ◽  
Author(s):  
Theresa Blume ◽  
Stefan Krause ◽  
Karin Meinikmann ◽  
Jörg Lewandowski
Keyword(s):  
Fiber Optic ◽  
Groundwater Discharge ◽  
Temperature Sensing ◽  
Distributed Temperature Sensing ◽  
Discharge Rates

scholarly journals Streambed Flux Measurement Informed by Distributed Temperature Sensing Leads to a Significantly Different Characterization of Groundwater Discharge

Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2312 ◽  
Author(s):  
Troy E. Gilmore ◽  
Mason Johnson ◽  
Jesse Korus ◽  
Aaron Mittelstet ◽  
Marty A. Briggs ◽  
...  
Keyword(s):  
Quantitative Methods ◽  
Groundwater Discharge ◽  
Temperature Sensing ◽  
Distributed Temperature Sensing ◽  
High Discharge ◽  
Randomized Sampling ◽  
Discharge Rates ◽  
Study Results ◽  
Solute Fluxes ◽  
Significant Difference

Groundwater discharge though streambeds is often focused toward discrete zones, indicating that preliminary reconnaissance may be useful for capturing the full spectrum of groundwater discharge rates using point-scale quantitative methods. However, many direct-contact reconnaissance techniques can be time-consuming, and remote sensing (e.g., thermal infrared) typically does not penetrate the water column to locate submerged seepages. In this study, we tested whether dozens of groundwater discharge measurements made at “uninformed” (i.e., selected without knowledge on high-resolution temperature variations at the streambed) point locations along a reach would yield significantly different Darcy-based groundwater discharge rates when compared with “informed” measurements, focused at streambed thermal anomalies that were identified a priori using fiber-optic distributed temperature sensing (FO-DTS). A non-parametric U-test showed a significant difference between median discharge rates for uninformed (0.05 m·day−1; n = 30) and informed (0.17 m·day−1; n = 20) measurement locations. Mean values followed a similar pattern (0.12 versus 0.27 m·day−1), and frequency distributions for uninformed and informed measurements were also significantly different based on a Kolmogorov–Smirnov test. Results suggest that even using a quick “snapshot-in-time” field analysis of FO-DTS data can be useful in streambeds with groundwater discharge rates <0.2 m·day−1, a lower threshold than proposed in a previous study. Collectively, study results highlight that FO-DTS is a powerful technique for identifying higher-discharge zones in streambeds, but the pros and cons of informed and uninformed sampling depend in part on groundwater/surface water exchange study goals. For example, studies focused on measuring representative groundwater and solute fluxes may be biased if high-discharge locations are preferentially sampled. However, identification of high-discharge locations may complement more randomized sampling plans and lead to improvements in interpolating streambed fluxes and upscaling point measurements to the stream reach scale.

scholarly journals Limitations of fibre optic distributed temperature sensing for quantifying surface water groundwater interactions

2014 ◽  
Vol 11 (7) ◽  
pp. 8167-8190 ◽  
Author(s):  
H. Roshan ◽  
M. Young ◽  
M. S. Andersen ◽  
R. I. Acworth
Keyword(s):  
Surface Water ◽  
Temperature Difference ◽  
Groundwater Discharge ◽  
Water Injection ◽  
Temperature Response ◽  
Temperature Sensing ◽  
Hot Water ◽  
Apparent Temperature ◽  
Distributed Temperature Sensing ◽  
Simulated Surface

Abstract. Studies of surface water–groundwater interactions using fiber optic distributed temperature sensing (FO-DTS) has increased in recent years. However, only a few studies to date have explored the limitations of FO-DTS in detecting groundwater discharge to streams. A FO_DTS system was therefore tested in a flume under controlled laboratory conditions for its ability to accurately measure the discharge of hot or cold groundwater into a simulated surface water flow. In the experiment the surface water (SW) and groundwater (GW) velocities, expressed as ratios (vgw/vsw), were varied from 0.21% to 61.7%; temperature difference between SW-GW were varied from 2 to 10 °C; the direction of temperature gradient were varied with both cold and-hot water injection; and two different bed materials were used to investigate their effects on FO_DTS's detection limit of groundwater discharge. The ability of the FO_DTS system to detect the discharge of groundwater of a different temperature in the laboratory environment was found to be mainly dependent upon the surface and groundwater flow velocities and their temperature difference. A correlation was proposed to estimate the groundwater discharge from temperature. The correlation is valid when the ratio of the apparent temperature response to the source temperature difference is above 0.02.

High-resolution distributed temperature sensing to detect seasonal groundwater discharge into Lake Vaeng, Denmark

2013 ◽  
Vol 49 (9) ◽  
pp. 5355-5368 ◽  
Author(s):  
E. Sebok ◽  
C. Duque ◽  
J. Kazmierczak ◽  
P. Engesgaard ◽  
B. Nilsson ◽  
...  
Keyword(s):  
High Resolution ◽  
Groundwater Discharge ◽  
Temperature Sensing ◽  
Distributed Temperature Sensing

High-spatial-resolution Distributed Temperature Sensing System Based on a Mode-locked Fiber Laser

2020 ◽  
Author(s):  
Anton O. Chernutsky ◽  
Dmitriy A. Dvoretskiy ◽  
Ilya O. Orekhov ◽  
Stanislav G. Sazonkin ◽  
Yan Zh. Ososkov ◽  
...  
Keyword(s):  
Fiber Laser ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Temperature Sensing ◽  
Distributed Temperature Sensing ◽  
Sensing System

scholarly journals Thermodynamics of a fast-moving Greenlandic outlet glacier revealed by fiber-optic distributed temperature sensing

2021 ◽  
Vol 7 (20) ◽  
pp. eabe7136
Author(s):  
Robert Law ◽  
Poul Christoffersen ◽  
Bryn Hubbard ◽  
Samuel H. Doyle ◽  
Thomas R. Chudley ◽  
...  
Keyword(s):  
Fiber Optic ◽  
Basal Layer ◽  
Temperature Sensing ◽  
Distributed Temperature Sensing ◽  
Catchment Scale ◽  
Outlet Glacier ◽  
Coarse Spatial Resolution ◽  
High Vertical Resolution ◽  
Fast Motion ◽  
Strain Heating

Measurements of ice temperature provide crucial constraints on ice viscosity and the thermodynamic processes occurring within a glacier. However, such measurements are presently limited by a small number of relatively coarse-spatial-resolution borehole records, especially for ice sheets. Here, we advance our understanding of glacier thermodynamics with an exceptionally high-vertical-resolution (~0.65 m), distributed-fiber-optic temperature-sensing profile from a 1043-m borehole drilled to the base of Sermeq Kujalleq (Store Glacier), Greenland. We report substantial but isolated strain heating within interglacial-phase ice at 208 to 242 m depth together with strongly heterogeneous ice deformation in glacial-phase ice below 889 m. We also observe a high-strain interface between glacial- and interglacial-phase ice and a 73-m-thick temperate basal layer, interpreted as locally formed and important for the glacier’s fast motion. These findings demonstrate notable spatial heterogeneity, both vertically and at the catchment scale, in the conditions facilitating the fast motion of marine-terminating glaciers in Greenland.

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