swat

Join the U.S. Department of Energy’s Bioenergy Technologies Office on Dec. 6, 2018, at 1 p.m. CST for a webinar on “Biomass Production and Water Quality in the Mississippi River Basin.” In this webinar, Argonne National Laboratory and Oak Ridge National Laboratory will jointly present modeling and analyses of potential implications of biomass production on nutrients and sediments in each of the six tributaries of the Mississippi River Basin. Presenters will describe the methodology, system boundary, and data sources and present water quality estimates for nitrogen, phosphorus, and suspended sediments under historical land use in the Upper Mississippi River Basin, Missouri River Basin, Ohio River Basin, Arkansas White and Red River Basin, Tennessee River Basin, and Lower Mississippi River Basin. The webinar will also provide an estimate of potential changes in water quality and quantity under future biomass production scenarios and discuss opportunities for integrating conservation practices with biomass production. The webinar will include a 15 minute Q&A segment.

Adding bioenergy to the U.S. energy portfolio requires long‐term profitability for bioenergy producers and
long‐term protection of affected ecosystems. In this study, we present steps along the path toward evaluating both sides of
the sustainability equation (production and environmental) for switchgrass (Panicum virgatum) using the Soil and Water
Assessment Tool (SWAT). We modeled production of switchgrass and river flow using SWAT for current landscapes at a
regional scale. To quantify feedstock production, we compared lowland switchgrass yields simulated by SWAT with estimates
from a model based on empirical data for the eastern U.S. The two produced similar geographic patterns. Average yields
reported in field trials tended to be higher than average SWAT‐predicted yields, which may nevertheless be more
representative of production‐scale yields. As a preliminary step toward quantifying bioenergy‐related changes in water
quality, we evaluated flow predictions by the SWAT model for the Arkansas‐White‐Red river basin. We compared monthly
SWAT flow predictions to USGS measurements from 86 subbasins across the region. Although agreement was good, we
conducted an analysis of residuals (functional validation) seeking patterns to guide future model improvements. The analysis
indicated that differences between SWAT flow predictions and field data increased in downstream subbasins and in subbasins
with higher percentage of water. Together, these analyses have moved us closer to our ultimate goal of identifying areas with
high economic and environmental potential for sustainable feedstock production.

As the US begins to integrate biomass crops and residues into its mix of energy feedstocks, tools are needed to measure the long-term sustainability of these feedstocks. Two aspects of sustainability are long-term potential for profitably producing energy and protection of ecosystems influenced by energy-related activities. The Soil and Water Assessment Tool (SWAT) is an important model used in our efforts to quantify both aspects. To quantify potential feedstock production, we used SWAT to estimate switchgrass yields at a national scale. The results from this analysis produced a map of the potential switchgrass yield along its natural eastern range. To quantify ecological protection, we are using the SWAT model to forecast changes in water quality and fish richness as result of landscape alterations due to incorporating bioenergy crops. We have implemented the SWAT model in the Arkansas-Red-White region, which drains into the Mississippi River, and we present our methods here. We identified two sub-watershed for sensitivity analysis and calibration of the water quality results, and then, explored ways to apply the calibration results to the whole region and validate the model setup. We also present an overview of our research in which results from the calibrated regional SWAT model were used to analyze potential changes in fish biodiversity. Only by evaluating the energy and environmental implications of landscape changes can we make informed decisions about bioenergy at the national scale, and the SWAT model will enable us to reach that goal.