Introduction:

The southern coasts of the Caspian Sea represent one of the most dynamic and environmentally sensitive coastal zones of Iran. During recent decades, this region has undergone extensive land use and land cover (LULC) transformations under the simultaneous influence of natural processes and anthropogenic pressures.

Purpose:

This study was conducted to extract and analyze the spatiotemporal patterns of LULC changes along the southern Caspian Sea coasts from 2001 to 2023 and to assess their consequences for landscape structure and ecological connectivity.

Geographical area:

The study area includes the southern coastal belt of the Caspian Sea in northern Iran, encompassing the provinces of Gilan, Mazandaran, and Golestan.

Methodology:

To monitor these changes, Level-3 MODIS data from the MCD12Q1 Version 6.1 product were employed. After quality control, class extraction, and temporal integration, annual LULC maps were produced for the entire study period. To analyze landscape dynamics, transition matrix analysis and a set of landscape metrics, including patch density, mean patch size, edge density, and aggregation index, were applied. Long-term trends were evaluated using the Mann–Kendall test and Sen’s slope estimator. Classification performance was assessed through overall accuracy and the Kappa coefficient.

Results and Discussion:

The findings indicate that the regional LULC structure has experienced substantial change over the past 22 years. Evergreen needleleaf forests and permanent wetlands decreased by 74% and 78.5%, respectively. In contrast, open shrublands increased by 18.2%, grasslands by 9%, croplands by 2.6%, and urban areas by 4.2%.

Conclusion:

The results demonstrate a gradual transition in the landscape of the southern Caspian coasts from dense natural cover toward a more heterogeneous, fragmented, and human-dominated configuration. This trend may contribute to declining habitat quality, weakened ecological functions, and increased environmental vulnerability.