Title: | Assessing the impact of site-specific BMPs using a spatially explicit, field-scale SWAT model with edge-of-field and tile hydrology and water-quality data in the Eagle Creek Watershed, Ohio |
Authors: | Merriman, K.R., P. Daggupati, R. Srinivasan, C. Toussant, A.M. Russell and B. Hayhurst |
Year: | 2018 |
Journal: | Water |
Volume (Issue): | 10(10) |
Pages: | |
Article ID: | 1299 |
DOI: | 10.3390/w10101299 |
URL (non-DOI journals): | |
Model: | SWAT |
Broad Application Category: | hydrologic and pollutant |
Primary Application Category: | BMP and/or cropping system assessment |
Secondary Application Category: | tile drainage effects and/or processes |
Watershed Description: | 125 km^2 Eagle Creek, a tributary of the Maumee River that drains portions of Hancock and Hardin counties in northwest Ohio, U.S. |
Calibration Summary: | |
Validation Summary: | |
General Comments: | |
Abstract: | The Eagle Creek watershed, a small subbasin (125 km2) within the Maumee River
Basin, Ohio, was selected as a part of the Great Lakes Restoration Initiative (GLRI) “Priority
Watersheds” program to evaluate the effectiveness of agricultural Best Management Practices (BMPs)
funded through GLRI at the field and watershed scales. The location and quantity of BMPs were
obtained from the U.S. Department of Agriculture-Natural Resources Conservation Service National
Conservation Planning (NCP) database. A Soil and Water Assessment Tool (SWAT) model was
built and calibrated for this predominantly agricultural Eagle Creek watershed, incorporating NCP
BMPs and monitoring data at the watershed outlet, an edge-of-field (EOF), and tile monitoring sites.
Input air temperature modifications were required to induce simulated tile flow to match monitoring
data. Calibration heavily incorporated tile monitoring data to correctly proportion surface and
subsurface flow, but calibration statistics were unsatisfactory at the EOF and tile monitoring sites.
At the watershed outlet, satisfactory to very good calibration statistics were achieved over a 2-year
calibration period, and satisfactory statistics were found in the 2-year validation period. SWAT fixes
parameters controlling nutrients primarily at the watershed level; a refinement of these parameters
at a smaller-scale could improve field-level calibration. Field-scale modeling results indicate that
filter strips (FS) are the most effective single BMPs at reducing dissolved reactive phosphorus, and FS
typically decreased sediment and nutrient yields when added to any other BMP or BMP combination.
Cover crops were the most effective single, in-field practice by reducing nutrient loads over winter
months. Watershed-scale results indicate BMPs can reduce sediment and nutrients, but reductions
due to NCP BMPs in the Eagle Creek watershed for all water-quality constituents were less than 10%.
Hypothetical scenarios simulated with increased BMP acreages indicate larger investments of the
appropriate BMP or BMP combination can decrease watershed level loads. |
Language: | English |
Keywords: | best management practices (BMPs); Soil and Water Assessment Tool (SWAT); nutrients;
field-scale; Great Lakes Restoration Initiative (GLRI); edge-of-field (EOF); Western Lake Erie Basin (WLEB) |