Water table elevation and groundwater temperature from the outwash plain of the Otemma glacier forefield (Switzerland) from 2019 to 2021

Water table elevation and groundwater temperature from the outwash plain of the Otemma glacier forefield (Switzerland) from 2019 to 2021.
Data were collected by the research teams of Bettina Schaefli^1,2, Stuart N. Lane¹.

¹ Institute of Earth Surface Dynamics (IDYST), University of Lausanne, 1015 Lausanne, Switzerland

² Institute of Geography (GIUB), University of Bern, 3012 Bern, Switzerland

For further information, please contact:

• tom.muller.1@unil.ch

This dataset is first referenced and discussed in the research paper by Müller et al., 2022.

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Data Description

9 piezometers consisting of fully screened plastic tubes were installed at an averaged depth of 1.5 to 2m in the outwash plain of the Otemma glacier forefield (WGS84 : 45.93434 / 7.41209). They cover four transects perpendicular to the stream from downstream (A) to upstream to (D).

Water table elevation and temperature were recorded in each well at a 10 minute interval using SparkFun MS5803-14BA pressure sensors. Sensor resolution is 1 mm and 0.01 °C, sensor accuracy is ± 2 cm and ± 0.8°C. Sensor bias was verified and corrected by bi-monthly manual groundwater stage measurements. Water temperature was not manually corrected and may be subject to some unidentified bias.

Piezometer location can be visualized in overview_piezo.jpg

Piezometer coordinates are available in shapefile GPS_piezometers.zip (coordinate system: swiss LV95 (EPSG:2056))

Piezometers name matches the labelling used in Müller et al. 2022 (A1,A2 to D1,D2). Two additionnal piezometers (BinjUp & BinjDown) used for a specific salt tracing analysis (see ERT_timelapse_salt_tracer.gif at https://zenodo.org/record/6342767#.YjBRmTXjJlh) are also available. Finally an additional piezometer (B1-2) located between B1 and B2 is also available although it was not used in Müller et al. 2022.

Data Structure

df_piezometers.csv is formated as a tidy dataframe with 10 minute interval and following headers :
    - date : local date (UTC+01 with daylight saving time)
    - variable : parameter of interest, with following classes :
            w_elevation: Water table elevation [m. asl]
            w_temperature : Groundwater temperature [°C]
    - name : name of piezometer (see coordinates in GPS_piezometers.zip)
    - dateUTC : date with UTC timezone

Data can be quickly vizualized in plot_piezo.png or interactively in a browser using plot_piezo_interactive.html