Spatio-temporal monitoring of drought indices and their impact on vegetation cover in Zagros region, Iran under climate change scenarios

Climate change has caused major destructive effects across the world. Therefore, it is necessary to conduct studies to evaluate the impact of climate change on weather patterns and drought. In this research, the temporal-spatial monitoring of drought and its impact on the loss of Zagros vegetation under climate change scenarios in 2022 was carried out. For this purpose, four general atmospheric models (BCC-CSM1, CANESM2, HADGEM2-ES, NORESM1-M) were constructed under three representative concentration pathways (RCP 2.6, 4.5, and 8.5) for three future periods 2020 − 2039, 2040 − 2069 and 2070 − 2099 using data from 6 synoptic stations located in the wet and temperate areas in the Zagros region in western Iran. This region was chosen due to its history of droughts and predicted future droughts. Spatial-temporal variations of drought severity and frequency were studied using Standard Precipitation Index (SPI) and Standardized Precipitation Evapotranspiration Index (SPEI) indices in different periods until 2100. The results showed the area of extremely dry areas will increase by 47.9% in ( 2020 − 2039 ) compared to the base period (1984 − 2020 ). According to SPI results, on average, the frequency of droughts will increase by 1.9% by the end of the century. Analysis of SPEI showed that drought will be more severe in all future periods. Based on SPEI, drought frequency will increase by 2% in (2020 − 2039) relative to the base period, and by 0.3% to 2099. According to the results, the frequency and severity of droughts in the 21th century have become more severe, which is an obvious component of climate change in Zagros. As a result, when the land is damaged and vegetation and forests are destroyed, it will cause instability in all social, economic and ecosystem sectors, so appropriate measures must be taken to control and reduce possible effects.