Impacts of climate change and land use on the development of nutrient criteria

Numeric criteria are crucial for controlling cultural eutrophication and for protecting current and future water quality. Anthropogenic climate change and the modification of land use have the potential to influence the development of nutrient criteria. In this study, stressor-response models, land use-nutrient regression models, and terrestrial ecosystem health states were used to determine the criterion values of total nitrogen (TN), total phosphorous (TP), and chlorophyll a (Chl a) using field data from lakes and reservoirs in Heilongjiang Province. Analysis of covariance and nonlinear regressions were used to quantitatively characterize the impact of climate change on the development of nutrient criteria. The results indicated that there were no significant differences in the nutrient criteria obtained by the various methods. Climate change factors (such as temperature, precipitation, and wind speed) are predicted to influence the relationships between nutrients and Chl a, as well as land use and nutrient concentrations, as climate change persists. Climate change should be considered during the development of nutrient criteria, as climate-driven change and achieving a desired water quality without the threat of eutrophication in the future will require stricter nutrient criteria than those needed under the current climate conditions.