Recent estimates of the ground deformation from remote sensing and terrestrial data around the High Dam Area, Aswan, Egypt

Abstract

The Aswan High Dam, located in southern Egypt, is considered one of the most strategic engineering structures in Egypt. After its full operation of the dam in 1971, a series of micro-earthquakes occurred around the High Dam. The largest seismic event recorded in the region was in November 14, 1981, earthquake with a magnitude of 5.6 ML, located 60 km to the southwest of the dam. Due to the great importance of this area, a combination of remote sensing (InSAR) and terrestrial data (precise leveling) was used to shed light on the current state of crustal deformation in this area. The data collected from three leveling lines (six campaigns) covering the period 2013–2022 in addition to 107 SAR scenes (2017–2021) from the Sentinel-1 mission were used to estimate the up-to-date ground deformation of the study area. The results from both Small Baseline Subset (SBAS) and leveling measurements show that the fault normal velocity of the Spillway fault is approximately 3 ± 0.15 mm/yr. The obtained results coincide with the seismicity pattern recorded in the study area, as the seismic events close to the dam are characterized by normal fault mechanisms. Outcomes show the importance of combining terrestrial (leveling) and space geodetic techniques (InSAR) to map the active faults and estimate the deformation rates along these faults.

Keywords

• High dam
• Precise leveling
• Sentinel-1
• Land subsidence