Simulations of the groundwater-flow system in the Cache and Grand Prairie Critical Groundwater Areas, northeastern Arkansas (ver. 2.0, November 2024)

The Mississippi Alluvial Plain (MAP) is one of the most important agricultural regions in the United States and underlies about 32,000 square miles of Missouri, Kentucky, Tennessee, Mississippi, Louisiana, and Arkansas. The MAP region supports a multibillion-dollar agricultural industry. The MAP is part of the Mississippi Embayment with several water-bearing units that make up the Mississippi Embayment Regional Aquifer System (MERAS). These water bearing units include the Mississippi River Valley Alluvial aquifer, Claiborne aquifers and Wilcox aquifers. Two areas in northeastern Arkansas, the Cache and Grand Prairie areas have been designated as critical groundwater areas because of decades of groundwater declines that resulted from past and current water use. The objective of the report associated with this data release is to document and describe the construction, calibration, and results of two inset groundwater-flow models developed for the Cache River Critical Groundwater Area and Grand Prairie Critical Groundwater Area using the latest MODFLOW-6 code, this data release publishes these two models. Both models derived boundary conditions from the parent MERAS 3 regional model to provide higher resolution simulations in the Cache and Grand Prairie focus areas. This data release has two child items, one for the Cache model and another for the Grand Prairie model.

The Cache model data release also contains versions of model runs that support a Groundwater Journal paper titled “Effects of auto-adaptive localization on a model calibration using ensemble methods.”