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Mississippi Embayment Regional Aquifer Study

Model visualization


A ground-water flow model normally consists of dozens of computer files with lines of strange text and thousands of numbers. While these files are crucial to the operation of the model, they are typically not human friendly in terms of being able to see how water levels may decline with pumping through time. To this end, the use of software to transform the seemingly chaotic collection of numbers into a visually meaningful image is very helpful. As a result, this page will attempt to present images or animations of various stages of the MERAS model development. Check back often for updates!

Simulated groundwater declines in Central Arkansas


A groundwater-flow model of the Mississippi embayment was used to evaluate changes in water-level altitudes after the addition of wells that simulate potential future pumping from the Sparta aquifer in the Bayou Meto-Grand Prairie area of eastern Arkansas (shown within the black outline) for the 30-year period from 2007 through 2037. The animation portrays the time-lapse development of a cone of depression with a maximum water-level decline of approximately 102 feet, and a lesser cone of depression to the east. Selected wells are shown as grey vertical pipes. Water-level altitude declines range from 40 to 50 feet over most of the remainder of the Bayou Meto-Grand Prairie area.

The Mississippi embayment - declining water levels in a shallow aquifer


The USGS recently constructed a computer model of groundwater in the Mississippi embayment. This model was used to simulate the rise or decline of water level in a shallow aquifer. Water from this shallow aquifer is utilized by the agricultural based economy in the area. In the animation, groundwater levels decline more than 100 feet from 1870 to 2007 in some areas of the shallow Mississippi River Valley alluvial aquifer in Arkansas. When pumping is forecast to 2038, based on trends of past pumping amounts and climatic variations, areas with water level declines of more than 100 feet expand, extending into Missouri and Mississippi.

The Mississippi embayment - declining water levels in a deep aquifer


The USGS recently constructed a computer model of groundwater in the Mississippi embayment. This model was used to simulate the rise or decline of water level in a deep aquifer. Water from this deep aquifer is utilized to meet the industrial and public supply needs in the area. In the animation, groundwater levels decline more than 400 feet from 1870 to 2007 in some areas of the deep middle Claiborne aquifer in Arkansas and Louisiana. When pumping is forecast to 2038, based on trends of past pumping amounts and climatic variations, areas of water level declines from 100 to 200 feet expand throughout Arkansas, Tennessee, and Mississippi.

A look underground


Water, oil, and gas wells (shown as green lines) are drilled to hundreds or thousands of feet below land surface in a n area known as the Mississippi embayment. Information gathered from these wells was used to create a 3D computer mod el of underground hydrogeologic formations. Many of these formations (shown as shades of grey, blue, brown, or tan su rfaces) consist of layers of sand and clay. These formations are important because they contain ground water that can be pumped out of the ground and used for anything from drinking water for public supplies to irrigation water for cr ops to washing, cooling, or transporting products in industrial settings. With the ever increasing demand for water a nd concerns about availability and sustainability, visual tools such as this are important and helpful.

Where does all the water come from?


As the animation begins, the land surface of the Mississippi embayment fades away to reveal underground geologic formations (shown as shades of blue, brown, and gray surfaces). A slice deep into the earth cuts off the eastern half of the embayment so we can peer into the formations (aquifers) beneath the surface. The lower portion of different color ed water wells (orange, light blue, and dark blue lines) come into view as the formations rotate. Each color of the w ells represents a different layer of sand (aquifer) from which water is pumped. The wells are drilled from tens of fe et deep to over 1,000 feet below land surface. There are thousands of wells represented here, but there are many thou sands more that are not shown. All together, these wells pump, on average, enough water out of the ground to cover an average size county in about six inches of water -- everyday. This animation is another piece of the 3D computer mod el puzzle used to help manage the valuable water resource.

See additional USGS videos and photos at the USGS Video and Image Gallery

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