Water scarcity and climate change have put increasing pressure on the sensitive ecosystem of the Hyrcanian forests. The aim of this study is to assess changes in vegetation cover and water areas of the southern coast of the Caspian Sea using spectral indices and statistical analyses. Time series of four indices SAVI, EVI, MNDWI and AWEI were extracted from Landsat images (1369 to 1404) at 11 stations. The relationships between the indices were analyzed with Spearman's correlation coefficient and the trend of changes with the Mann-Kendall test (95% and 99% levels). The results showed that the correlation of SAVI with EVI is positive (station mean 0.69) and the correlation of MNDWI with AWEI is positive (mean 0.58). The negative correlation of SAVI with MNDWI (mean -0.72) indicates a proper separation of water indices from vegetation. The Mann-Kendall test showed that SAVI had a significant increasing trend (at both levels) in 9 stations (82%) and MNDWI had a significant decreasing trend at the 95% level (and 8 stations at the 99% level) in 10 stations (91%). This contrasting pattern indicates a relative restoration of vegetation cover at the same time as a significant reduction in water areas. The greatest reduction in water areas was observed at coastal stations (Bandar Anzali and Astara). Continuous monitoring using the MNDWI index and the Mann-Kendall test provides a generalizable pattern for similar studies.