CONSEQUENCES OF, AND RESPONSES TO, NATURAL HAZARDS AND HUMAN ACTIVITIES DURING A >40 CENTURY PERIOD ON EGYPT'S NILE DELTA MARGIN

Geoarchaeological study of settlements dating as far back as 42 centuries ago on Egypt’s Nile delta margin provides a unique long-term record of diverse natural hazards, human activities and their consequences. This 225 km-long stretch is positioned in a relatively stable geological setting of the SE Mediterranean. During most of this period, however, there has been a progressive relative rise in sea-level (1 to 5 mm/yr) due to eustatic rise and land subsidence. This resulted in burial by sediment (New Kingdom Mediba site) and/or submergence (Byzantine town of Tennis) of many centers near the coast. Abandonment of sites, their progressive shift landward and/or damage continues to the present (Port Said, Baltim); mitigation includes construction on pilings (Port Said) or on firm substrate (Alexandria).

More serious have been sudden destructive events, including: (1) marked climatic change such as the rapid drying event of the Nile 4200 years ago (Old Kingdom), and high Nile floods that destroyed Greek centers (Herakleion) now submerged in Abu Qir Bay and that left the Byzantine port of Pelusium land-locked; (2) seismic activity that caused uplift (Persian and Mamlukian remains on Mt. Cassius east of the delta), subsidence (in Alexandria Harbour), and triggered avulsion of the Pelusium Nile branch that isolated population centers along the Gulf of Tineh; and (3) volcanic activity (~3500 yrs B.P.) during the New Kingdom.

In recent time, large-scale human activities have supplemented natural hazards: Nile barrages and irrigation projects in the 19th Century, major modification of Nile flow by 2 dams and large reservoir (Lake Nasser) in the 20th Century, and ongoing diversion of Nile water to the Western Desert and Sinai. Serious effects such as accelerated coastal erosion, reduction of lagoons, increased salinization and transformation of the delta to a non-functional delta system are only partially mitigated by recent measures. These have potentially serious consequences at a time when Egypt continues to face rapid population growth and increased political instability in the region.