Water turbidity, as one of the most important physical indicators of water quality, plays a crucial role in ecological dynamics, light penetration, and the health of aquatic ecosystems. Zarivar Lake in Marivan, recognized as the largest natural freshwater lake in Iran, has experienced considerable water quality fluctuations in recent years due to increasing anthropogenic pressures and hydroclimatic changes. Therefore, accurate and continuous monitoring of water turbidity in this aquatic system is of great importance. The present study aimed to evaluate and compare the performance of various spectral indices for estimating water turbidity in Zarivar Lake using Sentinel-2 satellite imagery on a seasonal scale during 2019. For this purpose, four spectral indices including NDTI, TurbBow, TurbChip, and TurbLath were extracted from Sentinel-2 images after applying radiometric and geometric corrections. Field-measured turbidity data collected from 15 sampling stations were used as reference data for the calibration and validation of linear regression models. Model performance was assessed using the coefficient of determination (R²) and the root mean square error (RMSE). The results indicated that the NDTI index exhibited the highest explanatory power for turbidity variations (R² ranging from 0.76 to 0.89) and the lowest prediction error (RMSE ranging from 0.00413 to 0.00533 NTU) across all selected seasons, outperforming the other indices. Furthermore, the spatiotemporal patterns of turbidity revealed a significant increase during warm seasons, particularly in the marginal zones of the lake, and lower values during cold seasons and in the central parts of the lake. Overall, the findings demonstrate that the integration of the NDTI index with Sentinel-2 data provides a reliable, cost-effective, and efficient approach for spatiotemporal monitoring of water turbidity in shallow lakes and can serve as a robust scientific basis for sustainable management, environmental conservation, and decision-making processes concerning Zarivar Lake.