Prediction and Modeling

The age of groundwater is key in predicting which contaminants it might contain. There are many tracers and techniques that allow us to estimate the age—or mix of ages—of the groundwater we depend on as a drinking water supply.

Research by the USGS National Water Quality Assessment (NAWQA) Project on water quality of rivers and streams covers a broad range of topics, from nonpoint pollution issues to vulnerability of aquatic ecosystems. Dive in and find out more about current water-quality conditions, how and where water quality is changing, and the latest information on pesticides, nutrients, and other contaminants.

What is SPARROW? SPARROW (SPAtially Referenced Regression On Watershed attributes) is a watershed modeling technique for relating water-quality measurements made at a network of monitoring stations to attributes of the watersheds such as contaminant sources and environmental factors that affect rates of delivery to streams and in-stream processing. The core of the model consists of a nonlinear...

Selenium (Se) as a contaminant of ecosystems is bioaccumulative and causes reproductive effects in fish and wildlife. Ecosystem-scale Se modeling predicts Se bioaccumulation based on dietary biodynamics within site-specific food webs. The model can be used to forecast Se toxicity under different management or regulatory proposals or to translate a tissue guideline to a dissolved guideline.

When planning for a flood, there are three key questions that must be answered: What areas will be flooded? How deep will the flood waters get? When will the flood arrive? Historical flooding can help a community anticipate how much impact similar flood events could have, but there are other methods and tools that can provide more accurate and nuanced estimations of a wide variety of flood...

On August 5, 2015, U.S. EPA was conducting an investigation of the Gold King Mine near Silverton, Colorado. While excavating as part of the investigation, water began leaking from the mine tunnel, and about three million gallons of water and sediment were released into Cement Creek, a tributary of the Animas River. The USGS provided pre- and post-release water-quality and streamflow data from...

The USGS studies calcium carbonate mineral reactions in soils at the Amarigosa Desert Research Site (ADRS) near Beatty, Nevada, in order to better understand carbon dioxide transport to and from the soil surface, as well as sequestration of toxic elements in the soil.

Although calcium carbonate reaction kinetics has important application in several areas of Earth Science, the mechanism of natural organic matter mediation of carbonate minerals growth and dissolution rates remains largely unknown. This project uses multiple approaches to study calcium carbonate formation and dissolution rates in surface water and groundwater systems.