<p>Investigating the water quality of rivers that flow into the Caspian Sea is crucial for preserving its delicate ecosystem and maintaining environmental health. This study aimed to assess water quality by using various indices, create zoning maps through ordinary kriging to determine contamination locations, apply Principal Component Analysis (PCA) to identify crucial parameters, and establish a relationship between water quality indices and spectral reflectance. In addition, remote sensing indicators and geostatistical techniques were employed to evaluate the level of pollution and its spatial distribution. The results revealed significant variations in pollution levels across the rivers studied. The Haraz River exhibited the highest chemical pollution, with a high chemical Water Quality Index (WQI) value of 0.87, whereas the Talar River showed the highest physical WQI (6.36) and overall water pollution (6.53). Furthermore, the Babolroud River recorded the highest pollution in the Dissolved Oxygen Deficit Index (DODI) at 84.12 and Dissolved Oxygen Saturation (DO_sat) at 7.45. The Talar River had the highest measured Dissolved Oxygen (DO_measured) value of 18, and the pollution levels of the Talar and Haraz Rivers were determined by the Pollution Load Index (PLI) and Eutrophication Index (EI). PCA identified the chemical WQI as a critical factor for the Babolroud and Talar Rivers, while the DOsat index was significant for the Haraz River. Analysis of the relationship between water quality and remote sensing indices demonstrated a strong association between the Modified Normalized Difference Water Index (MNDWI) and chemical WQI in the Talar River, as well as a robust correlation between DOsat and MNDWI in the Haraz River. The Talar River also exhibited a direct correlation between the chemical WQI and the Bare Soil Index (BSI), which indicates increased turbidity.</p> Graphical Abstract <p></p>