Water Quality in the Mississippi
NASA Land Surface Models Capture Water Quality Trends in the Upper Mississippi Basin
Water Quality Concerns
Rising Water Quality Concerns
Over 20 million people in 50 cities rely on drinking water from the Mississippi River. Poor water quality costs millions of dollars each year in increased drinking-water treatment, smaller commercial fishing harvests, depressed property values, and lost tourism revenue.
Polluted Runoff
Excess nitrogen and phosphorus from agriculture, urban runoff and other sources cause algae blooms in the river and its tributaries and contribute to the growing 'dead zone' in the Gulf of Mexico.
Excess Nitrogen in the Upper Mississippi
According to the U.S. EPA, 50% of streams in the upper Mississippi River basin have excess nitrogen.
Total nitrogen concentrations (Source: Wadeable Streams Assessment)
Modeling Water Quality
Working with Texas A&M University's H2I Lab , NASA is extending the capabilities of Land Information System (LIS) to model water quality using Soil & Water Assessment Tool (SWAT) . SWAT is commonly used to model and predict water pollution, including the human impacts on landscape water quality.
USGS sites for validation in Upper Mississippi Basin
Using a prototype LIS-SWAT integration, daily nitrate loads were simulated across the 450,000 sq. km Upper Mississippi basin.
Water quality data from 15 USGS sites were used to validate the modeled nitrate loads. A total of 9400 in-situ observations were used in this evaluation.
Comparison with daily average nitrate load at USGS sites shows very high efficacy of LIS-SWAT.
>> Site # USGS 05484500
>> Site # USGS 05420500
>> Site # USGS 05446500
Conclusions
- Interoperable LIS-SWAT framework allows NASA to estimate water quality with improved accuracy.
- In addition to nitrate, LIS-SWAT can also simulate, phosphorous, sediment, stream temperature, and many more water quality variables.
- Understanding the impacts of increasing nutrient pollution throughout the Mississippi River basin is critical to water quality management decisions.
- This emerging partnership with Texas A&M's H2I Lab is already expanding NASA's capabilities in understanding human impacts on freshwater quality.
