International Journal of Marine Science, 2017, Vol.7, No.2, 8-18
16
important driving force enabling the formation of the spit inside the estuary by allochthonous sediments originally
from the coastal area. Mechanical analysis of the geological samples confirm the transportation of the coastal sand
to inside the Rosetta Estuary to form the spit. Erosion state and wave action played an important rule for the
displacement of the spit toward the riverside. The water (sea) level fluctuation can enhance the flow of the
seawater toward the riverside.
Migration of the Rosetta spit toward riverside was recognized. The rate of spit migration was estimated as 187
m/y through 8 years from 2007 to 2015. During 2007, spit was nearly close the outlet of Rosetta Estuary and this
problem was solved by dredging.
Factors enhance the formation of spit inside the Rosetta Estuary and its migration were diminish in water
discharge, change of water column salinity, limitation of sediments transported from river, erosion state of Rosetta
promontory, wave action, water level fluctuation, and other environmental factors. The forecasting of the new
location of the spit is important. The control of the water flow from Edfina Barrage is important to balance the
high salinity at the end of the Rosetta Estuary to reduce its environmental effects.
3.1 Added value of the paper
Spit is an example of harmonious coexistence between the nature and humans with unique abundance of natural
and cultural properties. Spit cultural landscape reflects changes in the natural environment and local community,
the need for deliberate action and ability to choose the appropriate forms of activity in order to survive in the
hanging environment. The updating geomorphological changes is very important prerequisite for the protection of
the Rosetta Estuary. Its study is important for the overall and sustainable strategy for integrated coastal zone
management and forecasting of the future coastal changes. Spit formation and migration inside the Rosetta
Estuary is considered as indicator to test environmental changes in the study area, which not only affect the
estuarine ecology, they also affect the stability of the shoreline, water salinity change, social and economic value
of estuaries. Increase of salinity of the Rosetta Estuary may be effect on adjacent agricultural area due to
salt-water intrusion.
The factors that enhance the spit formation inside the estuary and its migration are listed. This data is important
for the ICZM approach and sustainable development of the study area, and also to predict the new site for the spit
and its environmental effects.
Previous study that has been discussed the Rosetta spit was published since 14 years ago and includes data series
lasted in year 2000. In order to update this document, this work was planned and prepared for study the spatial and
temporal variation of the spit with its new form.
3.2 Main differences between two studies
The previous work study the Rosetta promontory during the period 1922-2000. This period characterized by
severe erosion for the Rosetta headland. This study focused on the shoreline retreat. During this period, all the
formed spits were found at the tip of the promontory and it has different nature than the recent spits. Its
movements were due to the erosion of the Rosetta headland. During this work, the period of study was from 2007
to 2015. The behavior of the spits are different from the old period (1922-2000). It formed and migrated inside the
Rosetta Estuary with different source of sands.
The previous work calculated the rate of the retreat of the Rosetta promontory land to estimate the amount of lost
land. This information was important during the period of study of this previous work but after the establishment
of the Rosetta seawalls the shoreline is fixed in front of the seawall but the erosion is still happen but vertically. In
this work, the rate of the spit movement toward riverside was estimated and simple mathematical model deduced
to estimate the future migration.
The previous work did not mention the salinity differences inside the estuary. In this work, field measures of
salinity through the water columns indicated the present of saline water replaced the freshwater inside the Rosetta
estuary. The presence of saline water inside the estuary result salt-water intrusion into the agricultural land around.
