| Title: | Riparian buffer effectiveness as a function of buffer design and input loads |
| Authors: | Jiang, F., H.E. Preisendanz, T.L. Veith, R. Cibin and P.J. Drohan |
| Year: | 2021 |
| Journal: | Journal of Environmental Quality |
| Volume (Issue): | 49 |
| Pages: | 1599-1611 |
| Article ID: | |
| DOI: | 10.1002/jeq2.20149 |
| URL (non-DOI journals): | |
| Model: | SWAT |
| Broad Application Category: | pollutant only |
| Primary Application Category: | model and/or data interface |
| Secondary Application Category: | pollutant cycling/loss and transport |
| Watershed Description: | 370 km^2 Spring Creek, which has a groundwater contributory area of 450 km^2 and is located in Centre County, Pennsylvania, U.S. |
| Calibration Summary: | |
| Validation Summary: | |
| General Comments: | |
| Abstract: | Although many agricultural watersheds rely heavily on riparian buffer adoption
to meet water quality goals, design and management constraints in current policies create adoption barriers. Based on focus group feedback, we developed a
flexible buffer design paradigm that varies buffer width, vegetation, and harvesting. Sixteen years of daily-scale nutrient and sediment loads simulated with the
Soil and Water Assessment Tool (SWAT) were coupled to the three-zone Riparian
Ecosystem Management Model (REMM) to compare the effectiveness of traditional, policy-based buffer designs with designs that are more flexible and integrate features important to local farmers. Buffer designs included (i) 10 m grass,
(ii) 15 m grass, (iii) 15 m deciduous trees, (iv) 30 m grass and trees, (v) 30 m
grass and trees with trees harvested every 3 yr, and (vi) 30 m grass and trees
with grass harvested every year. Allowing harvesting in one zone of the buffer
vegetation (either trees or grasses) minimally affected water quality, with annual
average percent reductions differing by <5% (p > .05; 76–78% for total nitrogen
[TN], 51–55% for total phosphorus [TP], and 68% for sediment). Under the highest input loading conditions, buffers with lower removal efficiencies removed
more total mass than did buffers with high removal efficiencies. Thus, by focusing on mass reduction in addition to percent reduction, watershed-wide buffer
implementation may be better targeted to TN, TP, and sediment reduced. These
findings have important implications for informing flexible buffer design policies and enhanced placement of buffers in watersheds impaired by nutrient and
sediment. |
| Language: | English |
| Keywords: | |