| Title: | Examining a model and assessing its performance in describing nutrient and sediment transport dynamics in a catchment in southwestern Finland |
| Authors: | Bärlund, I. and T. Kirkkala |
| Year: | 2008 |
| Journal: | Boreal Environment Research |
| Volume (Issue): | 13(3) |
| Pages: | 195-207 |
| Article ID: | |
| DOI: | |
| URL (non-DOI journals): | http://cat.inist.fr/?aModele=afficheN&cpsidt=20471109 |
| Model: | SWAT |
| Broad Application Category: | hydrologic and pollutant |
| Primary Application Category: | hydrologic assessment |
| Secondary Application Category: | pollutant cycling/loss and transport |
| Watershed Description: | The Yläneenjoki catchment, 233 km^2 in area, is located on the coastal plains of south-western Finland, thus the landscape ranges in altitude from 50 to 100 m a.s.l. The soils in the river valley are mainly clay, whereas moraine and peat soils dominate elsewhere in the catchment. Long-term (1961–1990) average annual precipitation is 630 mm of which approximately 11% falls as snow. The highest discharges typically occur in spring and late autumn. Agriculture in the Yläneenjoki catchment consists of mainly cereal production and poultry husbandry and in this part of Finland agriculture can be considered as intensive for Finnish standards. |
| Calibration Summary: | Altogether, 28 parameters were used for calibration, which is ca. 10% of all the parameters used to run the SWAT model. The Nash-Sutcliffe Index (NSI) for the different output variables varied between –263 and 0.43, the linear goodness-of-fit (R2) values between 0.01 and 0.57. The best result was achieved for discharge and nutrient loads. Except for suspended sediments, the load simulation performed better than the concentration simulation. Even though the calibration result showed clear weaknesses, and further calibration thus is required, the model performance analysis was continued since the overall graphical match between the measured and simulated timelines was acceptable to the water manager of this exercise. |
| Validation Summary: | A validation of this SWAT set-up was attempted against data at the same Vanhakartano location for the period 1995-1999. The intention was to use the model run with unchanged parameter set against independent data series as a further analysis of the model performance, not as a proof of overall validity. With the exception of suspended sediment load and concentration, the validation performance was poorer than the calibration result. A second validation was performed concerning the average concentrations of total nutrients along the main stream. This analysis revealed further major problems in the present model set-up to describe catchment dynamics. |
| General Comments: | The article can be found in the net as pdf under: http://www.borenv.net/ or directly at: http://www.borenv.net/BER/pdfs/ber13/ber13-195.pdf. |
| Language: | English |
| Keywords: | Europe; Scandinavia; Finland; Communication; calibration; discharge; Environment; scale models; water quality; surface water; management; lakes; biomass; concentration; projects; drainage basins; dynamics; sediment transport; nutrients; performances; models |