Revisiting Major Dry Periods by Rolling Time Series Analysis for Human-Water Relevance in Drought

Drought is increasingly gaining importance for society, humans, and the environment. It is analyzed commonly by the use of available hydroclimatic or hydrologic data with little in-depth consideration of specific major dry periods experienced over a region. Also, it is not a common practice to assess the probability of drought categories with a rolling time series and hence the changing knowledge for operational drought monitoring. A combination of such quantitative analysis with a comprehensive qualitative assessment of drought as a human-water relation aimed to fill this gap performing a case study in the Seyhan River Basin, Turkey. Six major dry periods were identified from the precipitation time series of 19 meteorological stations. Major dry periods were analyzed by rolling time series and full time series, and they were also analyzed individually. A major dry period could be important in terms of its duration while another in terms of its severity or intensity, and each with its own impact on the human-water relations that can be influential on the drought mitigation, management and governance. Significantly higher probabilities were calculated for extreme droughts with the use of individual major dry periods. An important outcome from the study is that drought is underestimated in practice with the sole use of the whole data record.