| Title: | A watershed modeling framework for phosphorus loading from residential and agricultural sources |
| Authors: | Sinclair, A., R. Jamieson, A. Madani, R.J. Gordon, W. Hart and D. Hebb |
| Year: | 2014 |
| Journal: | Journal of Environmental Quality |
| Volume (Issue): | 43(4) |
| Pages: | 1356-1369 |
| Article ID: | |
| DOI: | 10.2134/jeq2013.09.0368 |
| URL (non-DOI journals): | |
| Model: | SWAT |
| Broad Application Category: | hydrologic and pollutant |
| Primary Application Category: | on-site and/or municipal wastewater systems |
| Secondary Application Category: | model and/or data interface |
| Watershed Description: | 665 ha Thomas Brook located in the Annapolis Valley in Nova Scotia, Canada |
| Calibration Summary: | |
| Validation Summary: | |
| General Comments: | |
| Abstract: | Phosphorus (P) loading from residential onsite wastewater
systems (OWSs) into neighboring surface waters is a poorly
understood process in rural watersheds; this can be further
challenged when rural residential dwellings are intermixed with
agricultural land use. The objectives of this research were (i) to
design a P onsite wastewater simulator (POWSIM) to assess P
loads from individual or clusters of residential OWSs typically
used in Nova Scotia, Canada; and (ii) to simulate OWS P loads in
a mixed agricultural watershed (Thomas Brook Watershed [TBW],
NS) using the Soil and Water Assessment Tool (SWAT) model in
conjunction with POWSIM, to predict and compare P loading
from agricultural and residential sources. The POWSIM loading
tool has three computational components: (i) disposal field
selection and treatment media mass calculation, (ii) disposal field
P treatment dynamics, and (iii) soil subsurface plume P treatment
dynamics. The combination TBW POWSIM and SWAT modeling
approach produced a better simulation of baseflow total P (TP)
loads in both a predominantly residential subcatchment and
one dominated by agriculture than the SWAT model without
POWSIM. The residential subcatchment had 48% of its average
annual land use TP load (simulated) contributed by OWSs,
whereas the agricultural subcatchment had 39%. Watershed scale
sensitivity analyses of POWSIM input parameters for 18-
and 50-yr OWS operation periods found the P loading rate into
the disposal field, long-term P removal rates in the disposal field
and soil systems, soil maximum P sorption capacity, and mass of
native soil involved in P treatment to be most sensitive. |
| Language: | English |
| Keywords: | |