Infrared Measurements to Evaluate Groundwater Discharge in the Coastal Zone

Infrared images of surface temperature obtained from a remotely-controlled helicopter were compared with data measured in situ by optical fibre cables and thermometers for evaluating the groundwater discharge into the ocean. Soil surface temperature measured in situ at the transect line with thermister thermometers and optical fibre cable agreed well with the infrared thermal data. The electrical conductivity of the submarine groundwater discharge decreases with decreasing surface temperature, indicating that the infrared measurement can tell us the change in fresh component of submarine groundwater discharge. Therefore, the remotely-controlled infrared method is a good tool for monitoring the coastal environment including groundwater discharge into the coastal zone.