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کلیدواژهها
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Wetland degradation, Dust aerosol, Environmental threats, Influencing
factors, Remote Sensing.
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چکیده
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Analysis of change trends in lakes and wetlands (LWs) degradation, identification of the main driving forces, and exploration of their impact on dust pollution are of high
importance. This research investigated these issues in 30 LWs in Iran. Landsat imagery
sensors were used to calculate the wetland degradation index (WDI) during the period
1986-2024. Daily aerosol optical depth data were used to calculate dust event frequency
(DEF). The trend of changes in the severely degraded bed (SDB) of LWs was analyzed
using the Mann-Kendall test. The Mann-Whitney U test was used to compare the mean
degraded area before and after the change point. The contribution of influencing factors
to the SDB area was determined using Ridge Regression (RR), and their relationship with
DEF was determined using Spearman's correlation coefficient (𝘱 ). The results showed
that the area of SDB increased significantly in 23% of Iran's LWs (Z > +2.1; p < 0.05; t-
test/Mann–Whitney U test). Changes in precipitation, wind speed, vapor pressure, surface
pressure, albedo, land surface temperature, and runoff were the most important driving
factors during the pre-change period. In the post-change period, the importance of these
factors diminished across the majority of these critical wetlands, while the impact of
population pressure around most wetlands increased. A weak positive correlation was
observed between SDB and DEF in the Maharlu, Bakhtegan-Tashk, Meyghan, and Namak
Lake ( <0.28; P-value>0.05). However, a significant positive correlation was found
between SDB and DEF in the three important wetlands of Gomishan ( = 0.55), Parishan
( = 0.35), and Namak Lake ( =0.70). A notable association was found between DEF
variability and SDB dynamics, with considerable differences among wetlands. Effective
management is necessary to protect and restore endangered wetlands and reduce dust
hazards in Iran.
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