| Title: | Assessment of nitrogen inputs and yields in the Cibolo and Dry Comal Creek watersheds using the SWAT model, Texas, USA 1996–2010 |
| Authors: | Sullivan, T.P. and Y. Gao |
| Year: | 2016 |
| Journal: | Environmental Earth Sciences |
| Volume (Issue): | 75(9) |
| Pages: | |
| Article ID: | 725 |
| DOI: | 10.1007/s12665-016-5546-0 |
| URL (non-DOI journals): | |
| Model: | SWAT |
| Broad Application Category: | hydrologic and pollutant |
| Primary Application Category: | nitrogen cycling/loss and transport |
| Secondary Application Category: | hydrologic assessment |
| Watershed Description: | 1,159 km^2 dainage area encompasses the entirety of the Dry Comal Creek basin (337 km^2), the entirety of the upper portion of the Cibolo Creek basin, and the Clear Fork and Dietz Creek sub-basins in the middle portion of the Cibolo Creek basin (822 km^2). Cibolo Creek is an ephemeral stream whose monthly flow was 0 m3 s-1 for 141 of 180 months between 1996 and 2010. The Dry Comal Creek basin is ephemeral in its western portion, but contains Comal Springs in its eastern extent, which serves as the headwaters of the Comal River. Streamflow out of the western portion of the watershed is typically less than 0.1 m3 s-1 while the watershed outlet’s flow averaged 9.7 m3 s-1 between 1996 and 2010 (USGS, 2014). An analysis of land uses in 2000, reveals the area was predominately undeveloped with only 8.6% of the land area comprised of urban land classes. The predominant land class within the watershed was forest, comprising 52.8% of the land area. The next major land uses were grasslands at 18.5% and farming operations at 12.5% of the land area. Elevation within the study area varies from 613 m in the northern portion to 157 m along the far eastern and southern portions The eastern and southern portions of the study area are underlain by the Edwards Aquifer, which is the predominant source of fresh water for the area. |
| Calibration Summary: | |
| Validation Summary: | |
| General Comments: | |
| Language: | English |
| Keywords: | Nitrogen, nitrate, surface water contamination, surface water modeling, SWAT |