نوع مقاله : مقاله پژوهشی
نویسنده
Assistant Professor, Faculty of Natural Resources, University of Jiroft , Kerman,Iran
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسنده [English]
This study sought to investigate change patterns in the standardized surface soil moisture (SSM), standardized land surface temperature (SLST), and standardized normalized difference vegetation index (SNDVI) in Iranian arid and semiarid regions using the Mann-Kendall test. To this end, the temporal response of dust occurrences to terrestrial factors variations in 1, 3, 6, 9, and 12-month time-series was identified at different lag times using the cross-correlation (CC) method. The standardized dust concentration (SDC) in dusty days was also considered as a criterion for evaluating the performance of dust storms during the study period (2010-2018). The study's results indicated dust storms' decreasing and increasing trends from 2010 onwards in Iran's arid and semiarid regions, respectively. Moreover, the trend of SSM changes was found to be significantly positive at different time series (Z>+1.96) in both regions. A similar trend was also observed for SNDVI in long-term series across the study areas. However, while the SLST variations showed meaningful positive trends in the arid regions at various time series (Z>+4.5), it only showed a significant positive trend in the 1-month series (Z=+2.12) in semi-arid regions.
Furthermore, according to the strongest CC values, the temporal response of dust storms to changes in vegetation, LST, and SM occurred at 6, 12, and 3-month time series with different time lags in arid regions. Nonetheless, the temporal responses of dust events to vegetation and LST variations in the semi-arid regions were found at 12-month time series with a 1-month and 5-month time lags, respectively.
کلیدواژهها [English]