The scientific and professional communities recognize the causes and effects of the problem. These, in turn, create a number of challenges for the future, which can be summarized as follows (IAHR, 1999):
Rainfall/Runoff processes and modeling;
Groundwater management, monitoring and remediation;
Unsaturated zone: exchange with surface water and coupled flow;
Conflict resolution in water management;
Water resource management under climate change.
5.1 Rainfall/Runoff Processes and Modeling
The quality and performance of rainfall/runoff models have improved but there is still room for further improvement. Future research directions will include adaptation of models for use in the domain of hydroinformatics, refinement of flow and quality modeling, examination of management options (storage and treatment facilities), interactive, dynamic control required in real-time simulation studies.
5.2 Groundwater Management, Monitoring and Remediation
Today problems in groundwater management are concerned with overexploitation, water table lowering, water deficit and pollution. Improved land management, to increase groundwater recharge by reducing evaporation and, where appropriate, runoff, also warrants investigation. Further problems are created by land subsidence due to over exploitation. Any groundwater management activity has to be based on an adequate