A potentiometric-surface map represents the altitude at which water would stand in tightly cased wells completed at any location within the study area aquifer. Using the altitude of water levels measured in the study area, the potentiometric-surface map depicts points of equal altitude with contours denoting a given water-level altitude calculated by subtracting the water level measured from the land-surface elevation (National Geodetic Vertical Datum of 1929). The contour lines were created using computer-based program ArcGIS with an interval of 10 feet. The direction of water flow from areas of high elevation to low elevation can be interpreted using potentiometric-surface maps and areas of decreased groundwater levels can be identified. The 2014 potentiometric-surface map shows ten total cones of depressions: two large depressions, five small depressions, and three areas of decreased water levels. As with the 2010 potentiometric-surface map, one large depression begins in southeastern Arkansas County, near the Arkansas and Desha County line, and extends north into Prairie County, west into Lonoke County, and east into the western-most part of Monroe County. Even though the center of the depression had deepened in 2010, the area of the cone in Arkansas County within the southeastern half of the depression had not expanded horizontally. The analysis of the 2014 potentiometric-surface map suggests no horizontal expansion in this area. The additional GIS shapefiles were used to depicts the western extent of the Mississippi River alluvial aquifer in eastern Arkansas on plates 1, 2, and 3 in Rodgers and Whaling (2020).

A potentiometric-surface map represents the altitude at which water would stand in tightly cased wells completed at any location within the study area aquifer. Using the altitude of water levels measured in the study area, the potentiometric-surface map depicts points of equal altitude with contours denoting a given water-level altitude calculated by subtracting the water level measured from the land-surface elevation (National Geodetic Vertical Datum of 1929). The contour lines were created using computer-based program ArcGIS with an interval of 10 feet. The direction of water flow from areas of high elevation to low elevation can be interpreted using potentiometric-surface maps and areas of decreased groundwater levels can be identified. The 2014 potentiometric-surface map shows ten total cones of depressions: two large depressions, five small depressions, and three areas of decreased water levels. As with the 2010 potentiometric-surface map, one large depression begins in southeastern Arkansas County, near the Arkansas and Desha County line, and extends north into Prairie County, west into Lonoke County, and east into the western-most part of Monroe County. Even though the center of the depression had deepened in 2010, the area of the cone in Arkansas County within the southeastern half of the depression had not expanded horizontally. The analysis of the 2014 potentiometric-surface map suggests no horizontal expansion in this area. The additional GIS shapefiles were used to depicts the western extent of the Mississippi River alluvial aquifer in eastern Arkansas on plates 1, 2, and 3 in Rodgers and Whaling (2020).

The Mississippi River Valley alluvial aquifer (MRVA) in eastern Arkansas is a major source of groundwater for public, industrial, agricultural, and aquaculture uses. Estimated withdrawals from the MRVA increased from 1,063 million gallons per day in 1965 (Halberg and Stephens, 1966) to 7,252 million gallons per day in 2005 (Holland, 2007). Potentiometric-surface maps, which represent the altitude at which water would stand in tightly cased wells completed at any location within in the study area, are produced to track water level changes over time (Schrader, 2010). This dataset contains 19 collections of digitized potentiometric surfaces, represented as potentiometric contours and rasters derived from those contours, from the early 1900s to 2008, and is loosely confined to the Mississippi River Valley alluvial aquifer extents inside Arkansas.

These netCDF output files from the Soil-Water-Balance Model contain daily calculations for the Mississippi Embayment Regional Aquifer System model domain of irrigation and net infiltration (recharge) amounts for the years 1915 to 1999. Input files used in the SWB run included historical agricultural land use as estimated by Sohl and others (2015), soil properties derived from NRCS gSSURGO and STATSGO data (Wieczorek, 2014), and 20th century gridded precipitation and air temperature as estimated by Livneh and others (2013). Spatial extent of the output files is the approximate boundary of the Mississippi Embayment Regional Aquifer System. Further details about the generation and application of the data can be found in Open File Report 2021-1008 (https://doi.org/10.3133/ofr20211008). These data are extracted from the model output contained in the companion model archive data release: https://doi.org/10.5066/P98PBR8O.

These netCDF output files from the Soil-Water-Balance Model contain daily calculations for the Mississippi Embayment Regional Aquifer System model domain of irrigation and net infiltration (recharge) amounts for the years 1915 to 1999. Input files used in the SWB run included historical agricultural land use as estimated by Sohl and others (2015), soil properties derived from NRCS gSSURGO and STATSGO data (Wieczorek, 2014), and 20th century gridded precipitation and air temperature as estimated by Livneh and others (2013). Spatial extent of the output files is the approximate boundary of the Mississippi Embayment Regional Aquifer System. Further details about the generation and application of the data can be found in Open File Report 2021-1008 (https://doi.org/10.3133/ofr20211008). These data are extracted from the model output contained in the companion model archive data release: https://doi.org/10.5066/P98PBR8O.

The Mississippi Alluvial Plain (MAP) has become one of the most important agricultural regions in the US, and it relies heavily on a groundwater system that is poorly understood and shows signs of substantial change. The heavy use of the available groundwater resources has resulted in significant groundwater-level declines and reductions in base flow in streams within the MAP. These impacts are limiting well production and threatening future water-availability for the region. This product will help not only scientists in our center, but also at a national level. This product will also be part of a larger study encompassing the Mississippi Alluvial Plain region. The Mississippi Alluvial Plain extent was delineated using GIS tools to represent the geographic extent of the Mississippi Alluvial Aquifer through incorporation of elevation information, geomorphology knowledge, ecological region extent, and previously published extents for part of the MAP region. The current MAP extent represents version 1.0. Future changes to the MAP extent will be tracked through increasing version numbers.

The Mississippi Alluvial Plain (MAP) has become one of the most important agricultural regions in the US, and it relies heavily on a groundwater system that is poorly understood and shows signs of substantial change. The heavy use of the available groundwater resources has resulted in significant groundwater-level declines and reductions in base flow in streams within the MAP. These impacts are limiting well production and threatening future water-availability for the region. This product will help not only scientists in our center, but also at a national level. This product will also be part of a larger study encompassing the Mississippi Alluvial Plain region. The Mississippi Alluvial Plain extent was delineated using GIS tools to represent the geographic extent of the Mississippi Alluvial Aquifer through incorporation of elevation information, geomorphology knowledge, ecological region extent, and previously published extents for part of the MAP region. The current MAP extent represents version 1.0. Future changes to the MAP extent will be tracked through increasing version numbers.

This dataset contains the contours, in feet, of the potentiometric-surface, spring 2020, Mississippi River Valley alluvial aquifer (MRVA). The contours are referenced to the North American Vertical Datum of 1988 (NAVD 88). The contours were derived from most of the available groundwater-altitude (GWA) data from wells and surface-water-altitude (SWA) data from streamgages, measured in for spring 2020. The potentiometric contours ranged from 10 to 340 feet (3 to 104 meters) above NAVD 88. The regional direction of groundwater flow was generally towards the south-southwest, except in areas of groundwater-altitude depressions, where groundwater flows into the depressions, and near rivers, where groundwater flow generally parallels the flow in the rivers.

This dataset contains the contours, in feet, of the potentiometric-surface, spring 2018, Mississippi River Valley alluvial (MRVA) aquifer. The contours are referenced to the North American Vertical Datum of 1988 (NAVD 88). The contours were derived from most of the available groundwater-altitude data from wells and surface-water-altitude data from streamgages, measured in for spring 2018. The potentiometric contours ranged from 10 to 340 feet (3 to 104 meters) above NAVD 88. The regional direction of groundwater flow was generally towards the south-southwest, except in areas of groundwater-altitude depressions, where groundwater flows into the depressions, and near rivers, where groundwater flow generally parallels the flow in the rivers.

This dataset contains the contours, in feet, of the potentiometric-surface, spring 2020, Mississippi River Valley alluvial aquifer (MRVA). The contours are referenced to the North American Vertical Datum of 1988 (NAVD 88). The contours were derived from most of the available groundwater-altitude (GWA) data from wells and surface-water-altitude (SWA) data from streamgages, measured in for spring 2020. The potentiometric contours ranged from 10 to 340 feet (3 to 104 meters) above NAVD 88. The regional direction of groundwater flow was generally towards the south-southwest, except in areas of groundwater-altitude depressions, where groundwater flows into the depressions, and near rivers, where groundwater flow generally parallels the flow in the rivers.