Monitoring the evolution of freshwater lakes is critical for understanding and mitigating eutrophication, a major environmental issue driven by excessive nutrient inputs, primarily nitrogen and phosphorus. This study focuses on Lake Lanalhue, where rising frequencies and intensities of algal blooms highlight significant ecological imbalances. By evaluating spatio-temporal variations in water quality and quantity parameters, meteorological conditions, and land use changes, we aim to uncover the drivers of eutrophication and their complex interactions. Nutrient concentrations, dissolved oxygen levels, and phytoplankton biomass are analyzed alongside hydrological parameters such as water level, volume, and surface area. The influence of meteorological factors, including temperature, precipitation, and wind speed, is assessed to determine their role in stratification, mixing, and nutrient cycling. Additionally, land use changes in the watershed, such as urbanization and agricultural practices, are examined to understand external nutrient inputs. This integrative approach provides a comprehensive understanding of the mechanisms driving changes in Lake Lanalhue, offering critical insights into the development of sustainable management strategies to mitigate eutrophication and its ecological and socio-economic impacts.