Disturbances of temperature-depth profiles due to surface climate change and subsurface water flow: 1. An effect of linear increase in surface temperature caused by global warming and urbanization in the Tokyo metropolitan area, Japan

A series of type curves is presented for evaluating vertical groundwater fl uxes under the condition of a linear increase in surface temperature. The d epths of minimum groundwater temperature in the temperature-depth profiles indicate the magnitude of the downward groundwater flux. The type curve met hod has been applied to the subsurface thermal regime observed in Tokyo met ropolitan area, Japan, to estimate the vertical groundwater fluxes under th e condition of surface warming caused by global warming and urbanization. T he groundwater fluxes obtained from the type curves and the depths of minim um groundwater temperature agree well with the values obtained from the oth er studies in the Tokyo metropolitan area. The inversion due to the surface warming could be a good tracer to detect the groundwater flow system.