مخاطرات محیط طبیعی (Dec 2019)
Investigating the performance of BADI Index: An improved approach to detect dust storms using MODIS imagery in West of Middle East
Abstract
Dust event is one of the atmospheric events of world arid and semi-arid regions that had a notable increase in a recent year and negative effects in different parts. MODIS imagery provides an acceptable data source for accurate and timely monitoring of dust storms. However, there are useful dust indices based on MODIS imagery. In this study, it has been used an improved brightness temperature adjusted dust index by Compound the brightness temperatures of three thermal infrared MODIS bands including band 20, band 31 and band 32 to monitor six representative dust storms over the West of Middle East between 2000 and 2016. When the dust storm indices of MODIS including the brightness temperature difference index in bands 32 and 31 (BTD32-31) and the normalized difference dust index (NDDI) and BADI compared together, the BADI index more accurately estimated the spatial density of dust storms in our study area. The regression analysis has been showing significant correlations between the BADI index and MODIS Deep Blue Aerosol Optical Depth values. For the Five dust storms, the determination coefficients (R2) of the regression between the BADI index and MODIS Deep Blue AOD values were 0.44, 0.48, 0.67, 0.53 and 0.45 (P < 0.01), respectively. Considering that BTD 32-31 and NDDI are two widely used indices to detect dust storm, we compared the results obtained using the BTD 32-31, NDDI and BADI for detection of a dust-storm event that occurred on 17 Jul 2016 in order to illustrate the advantages of the BADI. The BADI index with the standard density index of MODIS Deep Blue Aerosol Optical Depth had the statistically significant relationship at P ≤ 0.01.
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