The deterioration of water quality in rivers is a growing global concern. Nutrients, particularly nitrogen and phosphorus, play a key role in this degradation. The concentration of these nutrients in rivers is significantly affected by the increasing frequency and intensity of weather extremes (flood and drought) coupled with intensified land use (such as agriculture). However, the combined impact of weather extremes and land use on water quality in rivers is understudied. Therefore, it is critical to assess and deepen the understanding of the dynamics of nutrients under the influence of land use and climate change. This study aims to evaluate the long-term trends (over 30 years) of total phosphorus (TP) and total nitrogen (TN) loads, and to investigate the combined impact of flood, drought, and land use on the nutrient trends within Aurajoki river basin, South - West Finland. The utilized data will consist of long-term monitoring records of nutrient concentrations, discharge, temperature, precipitation, and CORINE Land Cover dataset. The data will be analyzed using Mann-Kendall statistics to assess trends, source apportionment to determine the contribution of land use to nutrient levels, and statistical modeling to evaluate the impact of both land use changes and weather extremes on nutrient loads. The findings will inform targeted interventions to protect and improve water quality in river ecosystems under changing environmental conditions.