Water resources management
Content Table
Water Resources and Sustainability
Managing regional or national water resources demands the integration of patterns and processes of both natural and social systems. This is essential to achieve the optimum interaction of man and nature since every aspect of water use and disposal impinges on ecosystems to a greater or lesser extent. Sustainability is the key issue: how can sustainable yields by abstraction from rivers, reservoirs and aquifers be defined so as to achieve the delicate balance between supporting economic development and lifestyle while still protecting the water environment from irreversible damage.
A first requirement is for more accurate information on how much water there is in a given area and at a given time at spatial and temporal scales that are of use to water resource managers. National river flow and groundwater archives are maintained in most countries to record and collate such information. In recent years, more sociological information is necessary on non-hydrological drivers and impacts, such as ownership and the real or implicit cost of land and water that have a profound effect on how water is used.
The variable climatic regimes in many areas, complicated by ever-increasing demands for better quality water by expanding populations, have put great pressure on water resource managers. Physically-based mathematical models are essential operational tools. These may still be limited by data and computational demands. Calibrations are possible for catchments with available discharge records but developments in remote sensing and Global Information Systems are necessary to provide quantitative links between model parameters and catchment topography, soils, vegetation and geology for viable regionalisation.
Hydrological extremes
Floods and drought are natural hazards that kill and affect most people world-wide. Accurate flood and drought estimation is therefore still a major issue in water resources management. Developments in space-time rainfall modelling and in distributed catchment modelling enable long catchment runoff series to be synthesised and thus improve rare-event estimation.
