Hydrology Of The Mississippi River Valley Alluvial Aquifer South Central United States PDF Download

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1998-06 edition. Excerpt: ...Mississippi and southern Tennessee. As shown in figure 1A, most of the Mississippi Alluvial Plain is a predevelopment discharge area for the five studied aquifers. The zone that had the largest predevelopment discharge, also in the northern area, was in the Mississippi Alluvial Plain east of Crowleys Ridge where the upper Claiborne aquifer subcrops the Mississippi River Valley alluvial aquifer. For the majority of this area, discharge to the alluvial aquifer was more than 0.2 in./yr, and in a small area (about 100 mi2) west of Memphis discharge from the upper Claiborne aquifer was more than 0.6 in./yr. Possible explanations for this large recharge and discharge in the northern area are (1) the middle Claiborne aquifer has large transmissivity, (2) the embayment is narrow and thus flow paths from recharge points to discharge points are shorter, and (3) high heads in the aquifer outcrop areas produce correspondingly higher heads in individual aquifers under the Mississippi Alluvial Plain, forcing flow upward into the upper Claiborne aquifer and thence into the Mississippi River Valley alluvial aquifer. Before development, aquifer outcrop areas in the eastern and western areas had more than 0.2 in./yr recharge in the upland areas of central Mississippi, south-central Arkansas, and northwestern Louisiana, but most of the outcrop areas had less than 0.2 in./yr recharge (fig. 1A). Predevelopment discharge from the aquifer system in the eastern and western areas was predominantly to the Mississippi River Valley alluvial aquifer, but some discharge was to large rivers and valleys. The Mississippi River Valley alluvial aquifer, which underlies the Mississippi Alluvial Plain, received as much as 0.2 in./yr discharge from the subcropping aquifers...