User:Vandhana38

Man has always faced weather and climate vagaries and problems related to droughts. However, the recent problems of inadequate water quality, which effectively reducedthe available resources, increased the severity of water deficits. Drought-related disasters have been more devastating than other natural hazards (earthquakes, volcanoes, etc), as far as deaths, suffering and economical damages are concerned. Apart from destructive direct effects, drought events have been followed by secondary, indirect calamities, such as famine, epidemics, fire, etc. Despite the progress in science and technology, man is still vulnerable to extreme drought events. The losses increase due to the continuing development of costly infrastracture, rise in population density, and decrease of the buffering capacities (deforestation, urbanization, drainage wetlands, etc). Understanding droughts, their occurrences, mechanisms, characteristics and regularities is of great importance for the design and management of water resource systems.The study of drought problems includes the following topics:  identification of meteorological causes and drought forecast

 evaluation of hydrologic drought characteristics at a site and over a region

 analysis of economic, environmental and social effects of drought

 definition of appropriate policy and management strategies for mitigating and controlling drought effects.

(a) Drought definition stage. In this stage, several disciplines recognize the importance of the analysis of such a natural hazard and try to identify the essential features of a definition of drought phenomenon.

(b) Drought description stage. This stage includes methods for analyzing historical droughts aiming at:

 evaluating the risk of future droughts

 determining the consequences on economy, environment, and society

 adopting an appropriate policy for mitigating drought effects

(c) Integrated system approach stage. In this stage, the single variable and single discipline approaches are recognized to be insufficient for providing a good understanding of drought problems. Many attempts have been made for a morecomprehensive analysis in order to characterize adequately the drought pheno-menon and also for developing a more effective action against its consequences.