| Title: | Modeling phosphorus in the Lake Allatoona Watershed using SWAT: II. Effect of land use change |
| Authors: | Lin, Z., D.E. Radcliffe, L.M. Risse, J.J. Romeis and C.R. Jackson |
| Year: | 2007 |
| Journal: | Journal of Environmental Quality |
| Volume (Issue): | 38(1) |
| Pages: | 121-129 |
| Article ID: | |
| DOI: | 10.2134/jeq2007.0111 |
| URL (non-DOI journals): | |
| Model: | SWAT |
| Broad Application Category: | hydrologic and pollutant |
| Primary Application Category: | land use change assessment |
| Secondary Application Category: | phosphorus cycling/loss and transport |
| Watershed Description: | 1618.9 km^ 2 Upper Etowah, 176.7 km^2 Shoal Creek, 572.9 km^2 Little/Noonday, 24.9 km^2 Owl/Kellogg, 164.8 km^2 Acworth/Allatoona and 122.1 km^2 Stamp/Rowland Rivers, which are all tributaries of the 2,870 km^2 Lake Allatoona drainage area located in northern Georgia, U.S. |
| Calibration Summary: | |
| Validation Summary: | |
| General Comments: | |
| Abstract: | Lake Allatoona is a large reservoir northeast of metropolitan
Atlanta, GA, threatened by excessive algal growth. We used the
calibrated Soil and Water Assessment Tool (SWAT) models
developed in our companion paper to estimate the annual P load
to Lake Allatoona in 1992 and in 2001 after significant changes
occurred in land use. Land use data in 1992 and 2001 from the
Multi-Resolution Land Characteristics (MRLC) Consortium
showed that forest land use decreased during this period by
about 20%, urban land use increased by about 225%, and
pasture land uses increased by about 50%. Simulation results
showed that the P load to Lake Allatoona increased from 176.5
to 207.3 Mg, which were 87.8% and 103.1%, respectively,
of the total P (TP) annual cap (201 Mg) set by the Georgia
Environmental Protection Division (GAEPD) for discharge
into Lake Allatoona. In the early 1990s, the greatest sources
of the TP load to Lake Allatoona (and their percentages of the
total load) were pasture (33.6%), forest (27.5%), and point
sources (25.0%). Urban land uses contributed about 6.0% and
row-crop agriculture contributed about 6.8%. A decade later,
the greatest two TP sources were pasture (52.7%) and urban
(20.9%) land uses. Point-source P loads decreased significantly
to 11.6%. Permit limits on poultry processing plants reduced
the point-source P loads, but increasing urban and pasture
land uses increased nonpoint sources of P. To achieve further
reductions in the P load to Lake Allatoona, contributions from
pasture and urban nonpoint sources will need to be addressed. |
| Language: | English |
| Keywords: | |