Impact of Climate Change on the Hydrology and Nitrogen Pollution in a Tile-Drained Agricultural Watershed in Eastern Canada

Abstract

The potential effects of climate change on the hydrology and nitrogen pollution of an agricultural watershed are predicted using the DRAIN-WARMF model. This newly developed, physically based hydrological model is applied on the St. Esprit watershed in southwestern Quebec, Canada. Under the assumption of no changes in land cover and land management, the model is applied in order to simulate annual, seasonal, and monthly changes in surface and subsurface flows and NO3-N loads at the outlet of the watershed under current and future climate conditions. The climate scenario under consideration in this study for 1961 to 2100 is based on projections from the Canadian Regional Climate Model (CRCM). The simulation results from the CRCM model suggest an increase in temperature and precipitation in the region being studied. These changes result in a significant increase in simulated mean annual and seasonal flow in the watershed. Moreover, water quality simulations under future climatic conditions show a significant increase in annual and seasonal NO3-N losses.