| Title: | Climate change impacts on nutrient loads in the Yorkshire Ouse catchment (UK) |
| Authors: | Bouraoui, F., L. Galbiati and G. Bidoglio |
| Year: | 2002 |
| Journal: | Hydrology and Earth System Sciences |
| Volume (Issue): | 6(2) |
| Pages: | 197-209 |
| Article ID: | |
| DOI: | 10.5194/hess-6-197-2002 |
| URL (non-DOI journals): | |
| Model: | SWAT |
| Broad Application Category: | hydrologic and pollutant |
| Primary Application Category: | climate change |
| Secondary Application Category: | pollutant cycling/loss and transport |
| Watershed Description: | 3500 km^2 Yorkshire Ouse, located in northern England in the United Kingdom (calibration results reported for the Ure (980 km^2) and Swale (1470 km^2) subwatersheds, and for the overall outlet of the Ouse). |
| Calibration Summary: | daily (1986-90) E values: Ure = .45 Swale = .39 OU SE = .77 |
| Validation Summary: | Monthly (1986-90) E values: nitrate = .64 ortho P = .02 |
| General Comments: | SWAT reproduced flows and nitrate loads with reasonable accuracy; ortho P results were poor due to inaccurate depiction of P inputs. Flow results could be improved with better representation of spatial rainfall patterns. Tabular comparisons of baseflow and surface flow versus measured data are shown. Uncertainty analysis based on 1,000 Monte Carlo simulations is also presented. Impacts of 6 climate change sceanrios are presented on total N and P losses (all nutrient losses were predicted to increase). More detailed hydrologic and nutrient impacts are reported for the two most extreme scenarios. |
| Abstract: | This study assessed the impact of potential climate change on the nutrient loads to surface and sub-surface waters from agricultural areas and was conducted using the Soil and Water Assessment Tool (SWAT) model. The study focused on a 3500 km^2 catchment located in northern England, the Yorkshire Ouse. The SWAT model was calibrated and validated using sets of five years' measurements of nitrate and ortho-phosphorus concentrations and water flow. To increase the reliability of the hydrological model predictions, an uncertainty analysis was conducted by perturbing input parameters using a Monte-Carlo technique. The SWAT model was then run using a baseline scenario corresponding to an actual measured time series of daily temperature and precipitation, and six climate change scenarios. Because of the increase in temperature, all climate scenarios introduced an increase of actual evapotranspiration. Faster crop growth and an increased nutrient uptake resulted, as did an increase of annual losses of total nitrogen and phosphorus, however, with strong seasonal differences. |
| Language: | English |
| Keywords: | SWAT model, climate change, nutrient loads |