Analysis of SPI as a Drought Indicator during the Maize Growing Period in the Cukurova Region (Turkey)

Abstract

One of the major challenges for agriculture related to climate change is drought. The increasing temperatures and decreasing precipitation in many parts of the world have enhanced the frequency and severity of drought events. Therefore, a detailed analysis is required in order to determine the drought frequency and take the necessary precautions. In this study, the climatic conditions in the agricultural region of cukurova (Turkey) were analysed. Meteorological data for the three provinces of Adana, Mersin, and Osmaniye were used. The aim was to calculate the Standardized Precipitation Index (SPI) for each of the three provinces analysed, and to use these values to detect drought during the different growth periods of maize. We also investigated whether the SPI values for the last 30 years differ significantly between the provinces. Furthermore, indicators such as the duration, magnitude, severity, recurrence, and drought frequency were also calculated. Using linear regression analysis, we determined whether there were trends in the multi-year data for the total precipitation and mean temperature. In addition, the water deficiency was determined by examining the amount of water required by maize and the adequacy of the precipitation in each development period. As a result, it was found that the cukurova region is prone to droughts, but they follow a mild course in most cases. However, no statistically significant differences were observed between the SPI values in the three provinces. The calculated average approximate drought recurrences (Tr) and expected intensities (lave) were Tr similar to 1.036 years and lave similar to 5.634 mm year(-1) in 3 years for Adana, Tr similar to 1.031 years and lave similar to -0.312 mm year(-1 )in 3 years for Mersin, and Tr similar to 1.052 years and lave similar to -0.084 mm year(-1) in 3 years Osmaniye. The research carried out in this paper confirmed that maize cultivation in the cukurova region is vulnerable to drought, and adaptation actions should be taken immediately.