A Cost‐Effective Probe for Monitoring Groundwater‐Surface Water Interactions

Abstract

Over the years, methods for measuring groundwater‐surface water (GW‐SW) interaction have improved significantly. The use of heat to quantify GW‐SW interaction has evolved with technical advancements. Recently, the use of temperature probes embedded with compact self‐recording temperature loggers has increased for measuring GW‐SW fluxes. However, these loggers are often expensive, making it difficult for researchers to use, especially for the dense networks. Eventually, this can be a hinderence for research in resource‐constrained scenarios. This work presents an affordable instrument (TemPro), designed for monitoring temperature at discrete depths. While the base TemPro system has a fixed initial cost ($89), the marginal cost of adding each additional sensor is approximately $3.48, whereas the total cost of commercially available logger‐based systems increases linearly with each additional sensor. The instrument was tested in the field and validated against one of the widely used sensors for environmental applications. The instrument was tested for consistency, agreement and reliability using different statistical metrics (NSE, R ² , RMSE, MAE and ICC). Furthermore, we have presented a case study where GW‐SW fluxes were estimated using both the reference instrument and the new temperature probe. The estimated fluxes closely matched those from the reference sensor, with a very low MRE (<2.5%). Therefore, this study demonstrates the potential to enhance GW‐SW monitoring in a spatially robust and cost‐effective manner using the developed instrument.