A series of type curves is presented for estimating vertical groundwater fluxes under the condition of a step increase in surface temperature. The depths of minimum groundwater temperature in temperature-depth profiles are used as an indicator of the magnitude of the downward groundwater fluxes. The type curve method has been applied to the subsurface thermal regime observed in experimental catchments in the Collie River Basin in southwest Western Australia to estimate the vertical groundwater fluxes under the condition of surface warming caused by land cover change from forest to agriculture. The groundwater fluxes obtained from the type curves and the depths of minimum groundwater temperature in temperature-depth profiles agree well with the values obtained from the other studies. ¿ 1999 American Geophysical Union