RN-41 : Analysis of low flow to investigate drought characteristics and plan water use management

Abstract

In spite of the lack of a unified definition of drought among the community of scientific professionals, it is basically agreed to be a situation of prolonged water deficit for given use, caused due to occurrence of below normal natural water availability reflected through deficient rainfall, low stream flows and consequent reduction in reservoir levels, depleted soil moisture and ground water. Therefore, the study of droughts is extremely relevant and essential aspect of water resources planning in order to meet the increasing demands on available water resources. Reliable estimation of low stream flows is necessary to investigate drought characteristics of the basin and suitable plan and manage water resources as the stream flows represent cumulative effects of rainfall deficiency and the changes in the basin both natural and man made due to drought conditions. Determination of low. flows is required to study the impact of drought on the stream flows to assess the capability of a particular stream to meet the water requirement of the area which is an important aspect of hydrological drought.

Most of the drought studies conducted, at least in India relate to the meteorological and agricultural aspects of drought whereas hydrological aspects of drought are less attempted in a scientific way. The report briefly covers the various aspects of hydrological drought and concentrates on low flow aspect as a measure of drought. A number of Able deterministic and statistical approaches used for ining magnitude, frequency and duration of low tlows ought analysis have been reviewed and presented with mention on stochastic approaches. An attempt has been review the approaches of low forecasting and their tion in planning drought management measures