1. Research Hydrologist, Lincoln Environmental Research, Private Bag 3062, Hamilton, New Zealand (corresponding author).
2. Research Associate, Institute of Hydrology and Meteorology, Dresden Univ. of Technology, Würzburger Str. 46, 01187 Dresden, Germany.
3. Professor, Institute of Hydrology and Meteorology, Dresden Univ. of Technology, Würzburger Str. 46, 01187 Dresden, Germany.
4. Professor, Institute for Groundwater Management, Dresden Univ. of Technology, 01062 Dresden, Germany.