Hydrological drought frequency analysis -a case study in South Kerala

摘要

Hydrological droughts refer to the shortfalls on surface or subsurface water supply like streamflow, reservoir, groundwater etc. Many people consider droughts to be a rare event, when in fact they are a normal and recurrent feature in the cycle of climatic events. Droughts in Indian peninsula seem to be primarily associated with the failure of monsoon. With climate change studies predicting even more hydrological extremes for the future, already competing demand for water resources may further aggravate. Thus, the importance of water resources aspect of drought is being increasingly recognised. In this paper, the severity of droughts in terms of the cumulative water deficiency is studied by two methods by proper identification of the threshold levels in two major basins of Kerala in the south. The streamflow for the basins are generated for a period of over two decades using the 'Thomas Fiering model'. An application of the drought frequency analysis by Yevjevich and Dracup methods is performed and presented.