Geography and Human Relationships

Geography and Human Relationships

Spatial-temporal analysis of drought intensity using remote sensing and SPI meteorological indicators with MODIS images (Case study: Iran)

Document Type : Original Article

Authors
1 golestan university
2 Non-Profit-Non-Governmental Institute,
10.22034/gahr.2025.502562.2374
Abstract
In this research, the relationship between meteorological drought index (SPI index) and remote sensing indices VCI, TCI and VHI has been investigated in the whole country. In this regard, by using the MODIS satellite images of Tera sensor and rainfall data from rain gauge and synoptic stations located in the country, the changes that occurred in the 10-year period were calculated. For this purpose, four months (April, May, June and July) were selected as a sample by examining the data of the available stations and using the Standardized Precipitation Index (SPI) model. In this study, considering the time accuracy, high spectral coverage, ease of access, no need for atmospheric correction and ground referencing, coded images (MOD11A2 and MOD13A2) from MODIS sensors of Terra satellite products from 2011 to 2020 due to the assurance of the existence of drought and drought phenomenon was used and then SPI index was compared with VCI, TCI and VHI indices in a consolidated manner. The results of drought monitoring showed that during this 10-year period in some years there was a severe drought in most of the studied stations, and in the same year there was less rainfall. For example, in 2012 this drought was very severe drought and in 2014 it showed a very wet year. The results of correlation between SPI index and remotely sensed drought indices showed that SPI index has the highest correlation with VHI index at the level of 0.01, which indicated that MODIS images and constructed indices have the necessary capability for drought monitoring. The results of this research can be a suitable option for decision-makers in order to investigate, monitor and resolve drought conditions effectively and doubles the necessity of defining a profile.
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Articles in Press, Accepted Manuscript
Available Online from 04 March 2025

  • Receive Date 27 January 2025
  • Accept Date 04 March 2025