A comparative drought assessment in Gilan, Iran using Pálfai drought index, de Martonne aridity index, and Pinna combinative index

• Published in: Arabian journal of geosciences 2022, Vol.15 (1), Article 90
• Main Authors: Jahangir, Mohammad Hossein, Danehkar, Shaghayegh
• Format: Article
• Language: English
• Subjects: Aridity; Climate; Climatic data; Drought; Drought index; Earth and Environmental Science; Earth science; Earth Sciences; Homogeneity; Mathematical analysis; Original Paper; Performance evaluation; Precipitation; Spatial distribution; Temperature; Weather stations
• ISSN: 1866-7511; 1866-7538
• DOI: 10.1007/s12517-021-09107-7

This paper discusses historical records of drought variations throughout Gilan province using three meteorological indices: Pálfai drought index (PaDI), de Martonne aridity index (IDM), and Pinna combinative index (IP); all are based on precipitation and temperature. The study examined the 1989–2018 time period, based on monthly climate data, collected from eleven selected meteorological stations. The main goal of the present work can be defined in two steps: first, evaluating the historical changes in drought conditions within the selected region based on three indices, due to the capability of these three indices to provide comparable results. Second, evaluate the performance of the PaDI in Gilan for the first time, and compare the similarities between its results with the other two. PaDI has been proven to be useful in portraying historical drought conditions in regions with relatively similar climate characteristics to Gilan province, and since it is based on the two most examined climate variables in climate and drought studies (precipitation and temperature), its results can easily be compared to findings of other similar studies that also utilizes precipitation-temperature based indices. According to the results, the designated period can be equally divided in two; each portrays one major peak in the drought trend. Spatial distributions for the peaks, in years 1999 and 2013 are illustrated for better understating of major drought-prone peaks during 1989–2018. Later, these results were compared with the calculated values of IDM and IP, showing high homogeneity between their results; accordingly, it can be concluded that the introduced index is applicable to the designated area.