Cetinkaya, C.P.; Gunacti, M.C. Meteorological and Agricultural Drought Risk Assessment via Kaplan–Meier Survivability Estimator. Agriculture2024, 14, 503.
Cetinkaya, C.P.; Gunacti, M.C. Meteorological and Agricultural Drought Risk Assessment via Kaplan–Meier Survivability Estimator. Agriculture 2024, 14, 503.
Cetinkaya, C.P.; Gunacti, M.C. Meteorological and Agricultural Drought Risk Assessment via Kaplan–Meier Survivability Estimator. Agriculture2024, 14, 503.
Cetinkaya, C.P.; Gunacti, M.C. Meteorological and Agricultural Drought Risk Assessment via Kaplan–Meier Survivability Estimator. Agriculture 2024, 14, 503.
Abstract
Dry periods and drought are inherent natural occurrences. However, due to the increasing pressures of global warming and climate change, these events become more frequent and severe on a global scale. These phenomena can be traced with various indicators and related indices proposed by various scholars. In general, drought risk assessment is done by modelling these indicators and determining the drought occurrence probabilities. The proposed adaptation introduces the "Kaplan-Meier Estimator," a non-parametric statistic traditionally used in medical contexts to estimate survival functions from lifetime data. The study aims to repurpose this methodology to assess drought risk by treating past droughts as "events" and evaluating the Standardized Precipitation Index (SPI) and Standardized Precipitation Evapotranspiration Index (SPEI) and map these results for a better understanding of the drought risks within larger spatial scales such as a river basin. The adapted method provides the probability of non-occurrence, with inverted results indicating the likelihood of drought occurrence. As a case study, the method is applied to SPI and SPEI values at different time steps (3, 6, and 12 months) across 27 meteorological stations in the Gediz River Basin, located in Western Turkey—a region anticipated to be profoundly affected by global climate change. The results are represented as the generated drought risk maps and curves, which indicate that (i) drought risks increase as the considered period extends, (ii) drought risks decrease as the utilized indicator timescales increase, (iii) locally plotted drought curves indicate higher drought risks as their initial slope get steeper. The method used enables the generation of historical evidence based spatially distributed drought risk maps which expose more vulnerable areas within the river basin.
Environmental and Earth Sciences, Sustainable Science and Technology
Copyright:
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