Short-Term Variation and Discharge Mechanism of the Futamata Hot Spring Estimated by Continuous Monitoring Data

Japan has abundant hot spring resources, which, if used appropriately, could contribute to CO2 emission reduction and socioeconomic development. Thus, for the appropriate use of hot spring resources, it is necessary to estimate the detailed discharge mechanism and its surrounding hydraulic characteristics. In our study, a hot spring monitoring device was developed and installed in the Futamata hot spring to evaluate its discharge mechanism. Comparison between the measured values of the monitoring device and the amount of precipitation indicated that this hot spring shows two types of water quality change trends depending on the intensity of precipitation. However, this was a short-term variation that could not be detected by conventional methods. To address this limitation, we created a new discharge mechanism model for the Futamata hot spring based on these observations, which allowed for the continuous observation of hot spring water using a monitoring device and was effective in detecting short-term variations. As such observations contribute to estimating the hydraulic structure around the hot spring, they are important for appropriate use of hot spring resources.