The study area, locally known as "the Delta", covers the Mississippi River Alluvial Plain in northwestern Mississippi. The Delta is a nearly flat southward sloping surface characterized by oxbow lakes, abandoned stram channels, natural levees, backswamp areas, and bayous.
The accompanying maps were prepared to show the effects of ground-water withdrawal on the alluvial aquifer during the growing season of 1981 and to compare water levels in September 1980. The maps are based on water-level measurements made in over 400 wells that tap the alluvial aquifers, the principal source of water supply for crop irrigation and fish farming in the Delta.
Water levels in April 1981 were lower than normal as a result of less-than-normal rainfall, low stream stages, and residual drawdown caused by pumping for irrigation during 1980. Water levels in September 1981 were lower than in September 1980 because levels were lower than normal at the beginning of the irrigation season, drought conditions continued, and pumping increased. The increase in pumping was caused by the increase in rice acreage and catfish farming and by supplemental irrigation of row crops affected by the drought.
