Title: Improved Standard Precipitation Index and drought characteristics
Authors: Zekâi Şen
Addresses: Engineering and Natural Sciences Faculty, Istanbul Medipol University, Beykoz, 34815, Istanbul, Turkey; Center of Excellence for Climate Change Research, Department of Meteorology, King Abdulaziz University, P.O. Box 80234, Jeddah 21589, Saudi Arabia
Abstract: In many regions of the world, and particularly in the eastern Mediterranean region, there is a general precipitation decrease tendency according to the global circulation model (GCM) and the regional climate change models (RegCM). Dry spells and their temporal occurrences as droughts affect water resources, and hence, agriculture and food securities may be endangered in such region. It is, therefore, necessary to foresee the future drought characteristics based on the historical records. Although the Standard Precipitation Index (SPI) provides dryness classifications, it cannot reflect the basic drought characteristics in the original hydro-meteorological records. The main purpose of this paper is to propose improved SPI (ISPI) approach for quantitative drought characteristics calculations. In order to support the insufficiencies in the classical SPI, a comparative study is presented with the ISPI method on the bases of drought duration, amount and intensity concepts. It is shown that especially the risk calculations have wide discrepancies, but the ISPI provides actual results. The application with objective results is presented for Istanbul European side, Turkey, meteorology station monthly precipitation records.
Keywords: drought; duration; global warming; intensity; precipitation; standard index.
International Journal of Global Warming, 2021 Vol.23 No.1, pp.1 - 10
Received: 05 May 2020
Accepted: 13 Jun 2020
Published online: 19 Jan 2021 *