In the past two decades several activities in the field of water resources management have been enhanced and intensified. This . rise had at least two independent reasons. The first and main one was the constantly increasing water demand for agriculture and industry on one side and the concern about the deteriorating environment on the other. While this last concern was lately overshadowed by deterioration of national economies, the quantity of available water resources has certainly not increased with the growing scarcity of funds for its development and protection. Furthermore, the standard of living, which raised across the world, even in India and China, countries which concentrate more than a third of the world population, has made people and their governments more aware of natural disasters caused by weather. Since a large percentage of losses in human life and material damage from weather-related disasters are caused by water, either by its excess or scarcity, the concern about water has been increasingly associated with these disasters. The second reason for intensified water resources management is man's spectacular technological advance in electronics, computers and use of satellites. The Koran says that two things cannot be predicted: the sex of the child in its mother's womb and the quantity of water that falls from the sky and flows in rivers. Technological progress has disproved both of these caveats.
Table of Contents1. Introduction.- 1.1 Definition of hydrological forecasting.- 1.2 Importance of forecasting in flood mitigation and water-resource management.- 1.3 New needs for hydrological forecasting.- 1.4 Classification of forecasts.- 1.5 Relationship of meteorological and hydrological forecasts.- 1.6 Use of Hydrological Operational Multipurpose Subprogramme (HOMS) of the World Meteorological Organization (WMO).- 2. Components of Hydrological Forecasting Systems.- 2.1 General description of the system.- 2.2 Historical and real-time data-collection sub-systems.- 2.3 Datatransmission sub-system.- 2.4 Data base management.- 2.5 Forecasting procedures (models).- 3. Selection of Forecasting Procedures.- 3.1 Comparisons of models.- 3.2 Sensitivity and interdependence of forecasting sub-systems.- 4. Forecast Updating and Evaluation.- 4.1 Forms in which forecasts are issued.- 4.2 Forecast updating techniques and error analysis.- 4.3 Evaluation of hydrological forecasts.- 5. Benefit and Cost Analysis of Hydrological Forecasts.- 5.1 Cost-benefit analysis.- 5.2 Cost-efficiency evaluation.- 6. Examples of Design of Hydrological Forecasting.- 6.1 Network design.- 6.2 Data-collection subsystems (sensors and transmission).- 6.3 Data-processing and modelling sub-systems.- 6.4 Forecast updating and dissemination.- References.- Annexes.- 1. Selected list of HOMS components related to hydrological forecasting.- 2. Results of a WMO survey of hydrological forecasting systems in Europe.- 3. Example of a system in the Pampanga River basin, Philippines.- 4. Example of a system in the Indus River basin, Pakistan.- 5. Examples of systems in the Amazon River basin, Brazil lower and middle Amazon and the Tocantins.- 6. Example of a system in the Yangtze River basin, China.- 7. Example of a system installed in and specifications for the data acquisition sub-system for the Niger River basin.- 8. Jhelum District Flood Order, Pakistan, 1980.- 9. Weekly hydrological bulletin (Poland).- 10. Low flow hydrological forecasts (River Niger).- 11. Glossary of terms.