Catchments
; Denitrification
; Land use
; Nitrates
; Runoff
; Calibration and validations
; Current equation
; Integrated catchment model
; Land managements
; Nitrate nitrogen
; Nitrogen loading
; Process-based modeling
; Semi-distributed
; Climate models
; denitrification
; hydrological modeling
; instream flow
; integrated approach
; land management
; land use planning
; model validation
; Finland
; Varsinais-Suomi
; Ylaneenjoki Basin
英文摘要:
The Integrated Catchment model for Nitrogen (INCA-N) is a semi-distributed, process based model that has been used to model the impacts of land use, climate, and land management changes on hydrology and nitrogen loading. An observed problem with the INCA-N model is reproducing low nitrate-nitrogen concentrations during the summer growing season in some catchments. In this study, the current equation used to simulate the rate of in-stream denitrification was replaced with an alternate equation that uses a mass transfer coefficient and the stream bottom area. The results of simulating in-stream denitrification using the two different methods were compared for a one year simulation period of the Yläneenjoki catchment in Finland. The alternate equation (Nash-Sutcliffe efficiency Combining double low line 0.61) simulated concentrations during the periods of the growing season with the lowest flow that were closer to the observed concentrations than the current equation (Nash-Sutcliffe efficiency Combining double low line 0.60), but the results were mixed during other portions of the year. The results of the calibration and validation of the model using the two equations show that the alternate equation will simulate lower nitrate-nitrogen concentrations during the growing season when compared to the current equation, but promote investigation into other errors in the model that may be causing inaccuracies in the modeled concentrations.
North Carolina State University, Department of Biological and Agricultural Engineering, Campus Box 7625, Raleigh, NC, United States; Finnish Environment Institute, P.O. Box 140, 00251, Helsinki, Finland
Recommended Citation:
Etheridge J,R,, Birgand F,et al. Technical Note: Alternative in-stream denitrification equation for the INCA-N model[J]. Hydrology and Earth System Sciences,2014-01-01,18(4)