US Egypt Cooperative Research: Evaluating Subsidence in the Nile Delta Using Radar Interferometry

Western Michigan University, Kalamazoo MI

Investigators

Abstract

1103843 This project supports a cooperative research project by Dr. Mohamed Sultan, Western Michigan University, Kalamazoo and Dr. Omar Cherif, National Authority for Remote Sensing and Space Sciences (NARSS) in Cairo, Egypt. They plan to use temporal satellite radar data to measure the spatial and temporal variations in subsidence rates across the entire Delta, identify the nature of the factors controlling modern subsidence, and predict the Delta response to these forcing factors over the next century. The interplay between natural and anthropogenic parameters controls subsidence rates and determines whether a delta progrades or erodes. Natural parameters include tectonic movements and millennial-to-decadal climate changes accompanied by wide swings in aridity and moisture and sea level fluctuations, whereas parameters based on human activity are probably largely related to extraction of groundwater and natural gas and impoundment of the Nile River by the Aswan High Dam. The PIs? radar interferometric (ERS-1 and ERS-2) studies over the northeastern section of the Nile Delta indicate that modern subsidence rates are high (up to 8 mm/yr) compared to average Holocene subsidence rates and that their spatial distribution is inconsistent with the distribution reported for the Holocene. The PIs propose to expand the ERS-based study area to include the entire Nile Delta. A geodetic component will be included to provide ground based measurements and calibrate the motions inferred from the interferometric analyses. Intellectual merit: The research will produce an assessment of subsidence rates throughout the entire Nile Delta and the identification of the factors controlling the subsidence. Because the PIs will be developing predictive tools that can potentially identify areas of high subsidence rates that are prone to sea water encroachment, the findings could be used to develop sound strategic plans for combating and/or modulating these adverse effects. In this respect our findings could be vital to the livelihood of at least half of Egypt?s 80 million citizens that inhabit the Delta and depend on it for their sustenance. The conditions described for the Nile Delta are typical of many of the world?s deltas, now witnessing destructional phases. To date, applications similar to those advocated here for the assessment of ongoing deformation in deltas and their controlling factors and for making realistic projections for subsidence over tens to hundreds of years have not been fully explored. Broader impact: The project results should lead to a successful demonstration of the advocated procedures in the Nile Delta which will invite similar applications for deltas elsewhere and could potentially be beneficial to the lives of hundreds of millions of people who inhabit these fragile systems. Also, the proposed activities will initiate and provide a vehicle for long-term collaborations between scientists with common interests (remote sensing, GIS and environmental Sciences) from NARSS, WMU, and UT. Two Graduate students and three undergraduate students will trained in new research techniques. Results from these studies will be incorporated in graduate/undergraduate remote sensing and GIS courses. All proposed tasks will be accomplished jointly by US scientists (from Western Michigan University and the University of Toledo) and their Egyptian colleagues (from the National Authority for Remote Sensing and Space Sciences) who will be receiving training in Egypt and USA on radar interferometric and geodetic applications. This proposal is supported under the US-Egypt Joint Fund Program where NSF supports the US side and the Government of Egypt funds the Egyptian side.