How Do Non-Floodplain Wetlands Affect Nonpoint Source Watershed Nutrient Fluxes?
Abstract
Nonpoint source (NPS) nutrient control measures implemented across the globe to improve drinking water quality and ecosystem health have not solved the unyielding challenge of excess aquatic nutrients. While managing sources of diffuse nutrients is critical, most efforts instead focus on nitrogen (N) and phosphorus (P) attenuation. Wetlands have long been heralded as efficient interceptors and attenuators of landscape nutrient fluxes because of their high residence times that promote elevated rates of denitrification, P-bound particulate settling, and microbial and plant uptake. However, current scientific understanding of wetland nutrient processing is based on local and plot-scale studies - or global syntheses of their N and P removal rates across landscapes. Watershed-scale models and analyses of NFWs and their impacts on nutrient fluxes are limited. We therefore ask: What are the water quality implications if non-floodplain wetlands, or NFWs, are restored or constructed across watersheds to intercept NPS pollution? What consequences would this have for reducing NPS nutrient fluxes to surface water systems? We explore this area of research using a multi-fold approach. First, we synthesize the science of the watershed-scale effects of NFWs on N and P-based water quality and identify emergent concepts that may advance future NFW watershed-scale results. Second, we develop process-based model simulations comparing nitrate-N fluxes in a watershed model with and without NFWs and demonstrate that models with NFWs result in decreased simulated watershed-scale nutrient fluxes and lower model output uncertainty. Finally, we provide a framework for advancing the science of watershed-scale water quality effects from wetlands to support NPS nutrient management.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.H41R1989G
- Keywords:
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- 0470 Nutrients and nutrient cycling;
- BIOGEOSCIENCES;
- 1630 Impacts of global change;
- GLOBAL CHANGE;
- 1831 Groundwater quality;
- HYDROLOGY;
- 1871 Surface water quality;
- HYDROLOGY