Drought monitoring and its effects on vegetation and water extent changes using remote sensing data in Urmia Lake watershed, Iran

Abstract The assessment of drought hazards is important due to their socio-economic impacts on water resources, agriculture, and ecosystems. In this study, the effects changing area canopy Lake Urmia watershed in northwest Iran have been monitored evaluated. For purpose, Standardized Precipitation Index (SPI) was calculated short medium periods (1-month 3-month) determine dry-spell basin. reviewing analysis, annual average has examined Furthermore, Moderate Resolution Imaging Spectroradiometer (MODIS) remote sensing data were used calculate Normalized Difference Vegetation (NDVI), Enhanced (EVI), Water (NDWI), Temperature–Vegetation–Dryness (TVDI) identify body, level, vegetation changes during 20 years (2000–2020). Pearson correlation coefficient also employed explore relationship between sensing-derived indices. According results 2000, 2002, 2004, 2006, 2008, 2010, 2012, 2014, 2016, 2018, 2020 had experienced dry spells NDWI showed that maximum happened its minimum recorded 2014. variation NDVI values highest cover estimated be 2,850 km2 in.2000, lowest value 1,300 in.2014. EVI TDVI while observed 2012 Also, analysis SPI with NDVI. Meanwhile, 1-month a higher than 3-month EVI. As concluding remark, more suitable indices monitor drought-related area. can make sound decisions regarding rapid water-related