scholarly journals Vulnerability Assessment for Sea Level Rise Impacts on Coastal Systems of Gamasa Ras El Bar Area, Nile Delta, Egypt

2021 ◽  
Vol 13 (7) ◽  
pp. 3624
Author(s):  
Ibrahim A. Elshinnawy ◽  
Abdulrazak H. Almaliki

The objective of the current study was to assess the vulnerability of coastal systems to sea level rise (SLR) impacts in the Gamasa Ras El Bar area, which is one of the most vulnerable coastal areas in the Nile delta, Egypt. To achieve the study objective, a field campaign was carried out to investigate, measure and collect data. These data, as well as historical data, were analyzed to identify projected inundation areas, erosion and accretion rates, shoreline changes, wave climate and saltwater intrusion, as well as drainage infrastructure efficiency. The results of a 73-cm SLR, projected up to the end of current century in the study area, indicate the following. Inundation areas will be about 2.16% of the study area. Although the significant wave height increased by 3.1 cm per year from 1999 to 2010, the results are indicative and might be taken into consideration in future coastal management plans. The expected variation in groundwater heads due to sea level rise will lead to an increase in groundwater heads ranging from 0 to 0.5 m above the current level. The change expected in groundwater will lead to saltwater intrusion by 1 km landward. The analysis of our results showed that about 271 km2 (60%) of the area under study will be negatively affected by rising groundwater. This area is occupied by about 70% of the localities in the study area. The analysis of the projected groundwater level rise showed that it will increase the discharges of the sub-drainage system by about 10% of the current rates and less than 1.2% for the open system. It is concluded that the drainage system has the sub-capacity to host the expected increase in drainage discharges without any modifications of the cross-sectional area of most of the drains. In addition, the coastal groundwater aquifer was found to be the most vulnerable system in the study area.

2016 ◽  
Vol 17 (2) ◽  
pp. 311-323 ◽  
Author(s):  
Hany F. Abd-Elhamid

Seawater intrusion is considered one of the main processes that degrade water quality by raising salinity. Over-pumping and decreasing recharge are considered the main causes of saltwater intrusion. Moreover, climate change and sea-level rise accelerate saltwater intrusion. In this paper SEAWAT code was used to study groundwater flow and seawater intrusion in the Eastern Nile Delta aquifer considering four scenarios of climate change including sea-level rise, increasing abstraction, decreasing recharge and the combination of these scenarios. The results showed that decreasing recharge has a significant effect on seawater intrusion. However, the combinations of these scenarios resulted in harmful intrusion and loss of groundwater. The soil salinity increased, which decreased agricultural production. The control of seawater intrusion and protection of groundwater resources and soil is very important. Different scenarios were implemented to protect the aquifer from seawater intrusion including decreasing abstraction, increasing recharge, abstracting brackish water and the combination of these three scenarios. The abstraction of brackish water gave a higher reduction of seawater intrusion and decreased groundwater table in the aquifer near the shore line, which protected the soil from salinity and increased agricultural production. However, the combination of these three scenarios gave the highest reduction of seawater intrusion.


Climate ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 69 ◽  
Author(s):  
Rabeya Akter ◽  
Tansir Zaman Asik ◽  
Mohiuddin Sakib ◽  
Marin Akter ◽  
Mostofa Najmus Sakib ◽  
...  

Salinity intrusion through the estuaries in low-lying tide-dominated deltas is a serious threat that is expected to worsen in changing climatic conditions. This research makes a comparative analysis on the impact of salinity intrusion due to a reduced upstream discharge, a sea level rise, and cyclonic conditions to find which one of these event dominates the salinity intrusion. A calibrated and validated salinity model (Delft3D) and storm surge model (Delft Dashboard) are used to simulate the surface water salinity for different climatic conditions. Results show that the effects of the reduced upstream discharge, a sea level rise, and cyclones cause different levels of impacts in the Ganges-Brahmaputra-Meghna (GBM) delta along the Bangladesh coast. Reduced upstream discharge causes an increased saltwater intrusion in the entire region. A rising sea level causes increased salinity in the shallower coast. The cyclonic impact on saltwater intrusion is confined within the landfall zone. These outcomes suggest that, for a tide dominated delta, if a sea level rise (SLR) or cyclone occurred, the impact would be conditional and local. However, if the upstream discharge reduces, the impact would be gradual and along the entire coast.


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