Towards a Sustainable Stability of Coastal Zone at Rosetta Promontory/ Mouth, Egypt

Abdelazim Negm

doi:10.4172/2332-2632.1000132

Abstract

Rosetta promontory/mouth where Rosetta branch of the Nile River meets the Mediterranean sea suffers from several severe environmental problems which began to take place since the beginning of the 20th century along Rosetta area, and increased dramatically since the construction of the Aswan High Dam (AHD) in 1964. It suffers from coastline erosion and sedimentation inside the inlet. The shoaling of the inlet leads to hindering the navigation process of fishing boats, negative impacts to estuarine and salt marsh habitat and decreases the efficiency of the cross section to transferring the flood flow to the sea. Many attempts to solve the erosion, and sedimentation problem were performed. Although, hard protection (and dredging) works have been implemented since 1989 including seawalls on the tip of the promontory and several groins along the eastern and western shores of the promontory, the problems still existing. This paper presents the results of testing a huge number of proposed alternative solutions to sustain the stable conditions of the Rosetta promontory/mouth. Hard structures, soft measures, combination of hard structures and soft measures were tested with and without nourishments of predetermined. The utilized Coastal Modeling System in testing the suggested measures was calibrated using collected field data from Ministry of Water Resources and Irrigation authorities and research institutes. The results indicated using only hard structures or soft measures without nourishment is not capable of keeping the Rosetta promontory/outlet stable. Only combination of both hard structures and soft measures with application of nourishment can improve the situation towards sustainable stable conditions but absolutely not the original stable conditions that were there before the construction of AHD.

Highlights

Seven major old deltaic branches of the Nile River are mentioned in various historical documents and in ancient maps
The results show that the eastern jetty has a remarkable effect on decreasing the siltation problem inside the outlet especially for jetty length exceeds 350 m
The hydrodynamic modeling was applied through two approaches to solve the coastal problems at Rosetta promontory in terms of obtaining an integrated long-term solution to enhance stability conditions of Rosetta estuary

Summary

Introduction

Seven major old deltaic branches of the Nile River are mentioned in various historical documents and in ancient maps. Both the Rosetta and Damietta branches discharge some freshwater directly and indirectly into the Mediterranean Sea to form the Nile estuary ( known as the Nile delta coastal area) Fluctuations in both quantity and quality of the Nile water reaching the Mediterranean, especially as a result of the Aswan High Dam (AHD) construction in 1965, have profoundly influenced the ecological characteristics of the river and the surrounding marine environment. These two main branches developed the Rosetta and Damietta promontories which have pro-graded during Holocene times into the Mediterranean Sea [2]. It was built during the years from 500 to 1000 AD when the water from the Canopic and Sebennitic branches, (Figure 1) was diverted naturally and/or artificially into an existing canal known afterwards as Rosetta Nile Branch [5]

Methods

Results

Conclusion