Assessing Land Deformation and Sea Encroachment in the Nile Delta: A Radar Interferometric and Inundation Modeling Approach. Issue 4 (16th April 2018)

• Record Type: Journal Article
• Authors: Gebremichael, Esayas; Sultan, Mohamed; Becker, Richard; El Bastawesy, Mohamed; Cherif, Omar; Emil, Mustafa
• Is Part Of: Journal of geophysical research. Volume 123:Issue 4(2018)
• Page Start: 3208
• Page End: 3224
• Publication Date: 2018-04-16
• Subjects: persistent scatterer interferometry -- Nile Delta -- flexure zone -- subsidence -- sea level rise -- hinge line; Geomagnetism -- Periodicals; Geochemistry -- Periodicals; Geophysics -- Periodicals; Earth sciences -- Periodicals; 551.1
• DOI: 10.1002/2017JB015084
• Languages: English
• ISSNs: 2169-9313

Abstract

Abstract: Persistent scatterer interferometric analyses were conducted on a stack of 84 Environmental Satellite's Advanced Synthetic Aperture Radar scenes spanning 7 years (2004 to 2010) over the entire Nile Delta of Egypt and surroundings (area: 40, 416 km 2 ) to monitor the ongoing spatial and temporal land deformation, identify the factors controlling the deformation, and model the interplay between sea level rise and land subsidence to identify areas and populations threatened by sea encroachment by the end of the 21st century. Findings include the following: (1) general patterns of subsidence (average rate: −2.4 mm/year) in the northern delta, near‐steady to slight subsidence in the southern delta (average rate: 0.4 mm/year), separated by a previously mapped flexure zone (minimum width: 20–40 km) undergoing uplift (average rate: 2.5 mm/year); (2) high subsidence rates (up to −8.9 mm/year) over the north central and northeastern delta (area: ~4, 815 km 2 ), possibly due to compaction of recent (<3, 500 years old), thick (>5 m) silt and clay‐rich Holocene sediments; (3) high subsidence rates (up to −9.7 mm/year) in areas where the highest groundwater extraction rates were reported in southern delta (Menoufia governorate) and in reclaimed desert land in the western delta (Beheira governorate); (4) high subsidence rates (up to −9.7 mm/year) over onshore gas fields, notably the Abu Madi gas field, where high gas extraction rates have been recorded; and (5) using extracted deformation rates, high‐resolution TanDEM‐X digital elevation model, a eustatic sea level rise of 0.44 m, and applying a bathtub inundation model, an estimated 2, 660 km 2 in northern delta will be inundated by year 2100. Key Points: Regional deformation patterns in Nile Delta largely caused by natural processes (compaction of Holocene sediments and flexural isostasy) Local deformation patterns are attributable to recent anthropogenic contributions such as high extraction of groundwater, oil, and gas Inundation simulations indicate 2, 660 km 2 will be submerged in northern delta by year 2100 given projected sea level rise/land deformation