Human-induced sedimentological changes in Manzala Lagoon, Nile Delta, Egypt

Abstract

The Manzala Lagoon in Egypt's Nile Delta has become a sediment sink of reduced area and depth, with increased contaminant levels. Loss of much-needed fresh to brackish water reserves and decreased fish catches have serious ramifications. Herein, maps of temporal and regional sediment distributions in Manzala incorporate petrological statistical analyses of 200 surficial and short samples. These provide baseline information ed to help implement protection measures for vital wetland. Four periods are considered: 1920s, 1940s, similar to 1965, and 1990. Important depositional changes between 1940s and similar to 1965 resulted anthropogenic effects on this quasi-closed lagoon system, including industrial buildup, wetland conversion to agricultural land, and irrigation waterway development. Further modification from similar to 1965 to 1990 is associated with closure of the Aswan High Dam, continued construction of waterways that discharge waste water into lagoon margins, and marine incursion into the northern lagoon. If current practices continue, the lagoon could be reduced to about one-third of its present area by 2050 AD.