Degradation trends in lakes and wetlands of Iran and their contribution to dust pollution

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 (p <0.28; P-value > 0.05). However, a significant positive correlation was found between SDB and DEF in the three important wetlands of Gomishan (p= 0.55), Parishan (p= 0.35), and Namak Lake (p=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.