B015-04
Can strategic buffers mitigate anthropogenic land cover impacts and improve coastal health?
Tuesday, 8 December 2020: 04:09
Virtual
Katherine L Martin1, Georgina Sanchez1, Danica Schaffer-Smith2, Elly Gay1, Ana Maria Garcia3, Julie E DeMeester4 and Ross Kendall Meentemeyer5, (1)North Carolina State University Raleigh, Raleigh, NC, United States, (2)Arizona State University, Center for Biodiversity Outcomes, Tempe, AZ, United States, (3)USGS North Carolina Water Science Center, Raleigh, NC, United States, (4)The Nature Conservancy North Carolina, Durham, NC, United States, (5)North Carolina State University, Center for Geospatial Analytics, Raleigh, NC, United States
Abstract:
Riparian buffers have been used to protect water quality from human land uses for decades, and their impacts at local and stream reach segments are well established. Less well understood is the scale and placement of riparian buffers required to improve water quality across regional scale watersheds, thus protecting coastal ecosystem health from upstream development and agricultural land uses, particularly in the context of changing climate. To address this gap, we are 1. Identifying the role that upstream land use change plays on downstream (coastal) water quality in the context of changing climate and 2. Examining whether
strategic buffers, those placed on local watersheds with the greatest extents of anthropogenic land use (urban development and row crop agriculture) provide significant improvements to whole watershed health (stream flow flashiness, sediment, and nutrients).We set the anthropogenic land use threshold for strategic buffers at 20%.
Our study system is the Cape Fear River basin, a regional (HUC 4) watershed encompassing 23,735 km2 of central and eastern North Carolina, USA. Land cover throughout the basin is patchy and approximately 12% developed, 38% forested, 21% agriculture, 18% wetlands and 10% other land cover types in the 2016 NLCD. Within sub-watersheds (HUC 12), total anthropogenic land cover ranges from < 1% to 84%, and exceeds 20% in 45/272 sub-watersheds. Many of these watersheds may be at a tipping point. Applying the FUTURES urban growth model, business as usual development is projected to add 2% urban land cover at a regional basin scale by 2060. At the sub-watershed scale, the mean (SD) increase in urban land cover is 16± 0.15, ranging from 0-58% increase and resulting in 163/272 of sub-watershed exceeding 20% anthropogenic land cover. We are now applying the SWAT hydrologic model to test the effectiveness of strategic buffers compared to no buffers or buffering all streams across the regional basin under current and 2060 land use and climate.
