| Title: | Effect of Watershed Delineation and Climate Datasets density on runoff predictions for the Upper Mississippi River Basin using SWAT within HAWQS |
| Authors: | Chen, M., Y. Cui, P.W. Gassman and R. Srinivasan |
| Year: | 2021 |
| Journal: | Water |
| Volume (Issue): | 13(4) |
| Pages: | |
| Article ID: | 422 |
| DOI: | 10.3390/w13040422 |
| URL (non-DOI journals): | |
| Model: | SWAT |
| Broad Application Category: | hydrologic only |
| Primary Application Category: | HRU, subbasin, grid and/or landscape unit delineation effects |
| Secondary Application Category: | baseflow, interflow and/or other hydrologic component analysis |
| Watershed Description: | 447,802 km^2 portion of the Upper Mississippi River Basin (UMRB) which drains to Grafton, Illinois), which is nested within the larger overall 491,700 km^2 UMRB system that drains parts of Iowa, Illinois, Minnesota, Missouri, South Dakota, Wisconsin, Indiana and Michigan in the north central U.S. |
| Calibration Summary: | |
| Validation Summary: | |
| General Comments: | |
| Abstract: | The quality of input data and the process of watershed delineation can affect the accuracy
of runoff predictions in watershed modeling. The Upper Mississippi River Basin was selected
to evaluate the effects of subbasin and/or hydrologic response unit (HRU) delineations and the
density of climate dataset on the simulated streamflow and water balance components using the
Hydrologic and Water Quality System (HAWQS) platform. Five scenarios were examined with the
same parameter set, including 8- and 12-digit hydrologic unit codes, two levels of HRU thresholds
and two climate data densities. Results showed that statistic evaluations of monthly streamflow from
1983 to 2005 were satisfactory at some gauge sites but were relatively worse at others when shifting
from 8-digit to 12-digit subbasins, revealing that the hydrologic response to delineation schemes can
vary across a large basin. Average channel slope and drainage density increased significantly from
8-digit to 12-digit subbasins. This resulted in higher lateral flow and groundwater flow estimates,
especially for the lateral flow. Moreover, a finer HRU delineation tends to generate more runoff
because it captures a refined level of watershed spatial variability. The analysis of climate datasets
revealed that denser climate data produced higher predicted runoff, especially for summer months. |
| Language: | English |
| Keywords: | SWAT; watershed delineation; climate data; UMRB; HAWQS; runoff prediction; water components |