Sedighifar, Z; Motlagh, MG; Halimi, M (2020). Investigating spatiotemporal relationship between EVI of the MODIS and climate variables in northern Iran. INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCE AND TECHNOLOGY, 17(2), 733-744.

Climate variability and fluctuations dramatically affect terrestrial ecosystems and their variations. Several studies have been conducted on the relationship between them in terms of use of vegetation indices. In this study, GIS-based spatiotemporal analyses were used to model the relationship between vegetation variations based on the EVI-MODIS and its response to land surface temperature (LST) and rainfall in Mazandaran province during the period of 2000-2016 in the north of Iran. The LST parameter was derived from the 17-year MODIS data, and rainfall parameter was achieved via meteorological station data in the region. Correlation and linear regression analyses at 0.95% confidence level (P value = 0.5) were used to study the relationship between spatiotemporal enhanced vegetation index (EVI) and two climatic parameters. The results indicated that the EVI had a rising trend over the study period. This was mostly due to the increase in paddy fields. The result also shows significant spatial correlation between EVI with LST values, which was direct during winter and inverse during summer. The tabulate area analysis showed that throughout the winter months, the spatial distribution of pixels matched the highest EVI values in pixels with a maximum temperature (20-27 degrees C), while during June to September, the maximum EVI values were related to areas where the LST was less than 25 degrees C. Although we found no significant simultaneous relationship between EVI/MODIS and rainfall in studied area, but by 1.5-2.5 months lag time in spring season, the relation between them reaches peak.