Hydrology and Earth System Sciences www.hydrol-earth-syst-sci.net 1027-5606 1607-7938 1 1 1997 10.5194/hess-1-47-1997 http://www.hydrol-earth-syst-sci.net/1/47/1997/ http://www.hydrol-earth-syst-sci.net/1/47/1997/hess-1-47-1997.html http://www.hydrol-earth-syst-sci.net/1/47/1997/hess-1-47-1997.pdf 47 53 0000-00-00 Recharge Response Functions A. Calver Institute of Hydrology, Wallingford, Oxfordshire OX10 8BB, U.K. This paper explores the establishment of transfer functions for describing the annual oscillation of unconfined aquifer water levels in response to effective precipitation. A simple saturated zone representation is developed to accompany the unsaturated zone mechanism. Practical examples are drawn from a sample of sites from the chalk and the Permo-Triassic sandstones of England and Wales. Modelled water levels are in many cases good. The technique is most appropriate within the usual range of fluctuation of aquifer water level, with no great change in influence of abstractions, and when it is acceptable to approximate the complexity of unsaturated zone processes in practical analysis.