Improved estimate of multiyear drought for water resources management studies

Abstract

Using short hydrological records to characterise extreme drought for water studies could lead to uncertain results. At first, this article introduces a generic model that extends the length of short hydrological records to improve the analysis of drought. Using simulated data, the extension model performance was tested and found to work well and later the model was used to extend the annual precipitation for Reba region back to 1924. The analysis of the extended precipitation shows the occurrence of 23 drought events that is about 50% more than the number of events detected from the analysis of the short historical precipitation. The analysis shows that events of 1 year duration are common while events of 3 years or more are rare. Furthermore, this article proposes a theoretical model that can be used to estimate the number of drought events that may emerge during a fixed period. The model is shown to be reliable, and the estimated drought numbers can be used in planning for the water supply from the traditional water sources. Moreover, the article suggests a few measures to improve the water supply in Jordan during dry conditions.