A geostatistical tool for drought management

Abstract Drought lead time is a useful tool to enable local reservoir operators to predict the possibility of the occurrence of a hydrological drought. Universal time kriging, a geostatistical technique, can be used to predict streamflows in low-flow seasons to yield an estimate of drought lead time for a given operating policy and initial conditions. This is an indicator of the severity of an approaching drought. The case study concerns a hypothetical reservoir in western Georgia. This area has experienced a number of drought periods in recent years. Using the actual and the estimated data, drought lead times for different initial storage values are calculated. The comparison indicates that the proposed procedure yields reliable estimates of drought lead time.