You must have a javascript-enabled browser and javacript and stylesheets must be enabled to use some of the functions on this site.
 
 Earthnet Home  
Introduction
Sessions and Session Summaries
Deadlines
First Annoucement
Scientific Committee
ESA Specific Links
Organising Committee
Programme
Round Table Discussion Questions
Conference Photos
List of Participants
Proceedings
All papers


 

Ground surface deformation around Tehran due to groundwater recharge: InSAR monitoring.

Michel Peyret (1), Jean Chery(1) , Noel Gourmelen(1) , and Jean-François Ritz(1)

(1) LGTS-CNRS, Universite de Montpellier II Place E.Bataillon, 34095, France

Abstract

Tehran is located on an active tectonic and seismic zone. The surface deformation monitoring provides a powerful tool for getting a better understanding of faults kinematics and mechanisms. Used in conjunction with GPS networks, InSAR (Interferometric Synthetic Aperture Radar) provides dense and precise deformation measurements which are essential for mapping complex heterogeneous deformation fields. Moreover, urban and arid areas preserve interferometric phase coherence. The archived acquisitions of ERS that span 9 months between September 1998 and June 1999 reveal wide areas of surface uplift (by as much as 9 cm). This vertical deformation (gradual in time) has probably no tectonic meaning but is rather the ground response to ground water recharge. These zones are all located dowstream of large alluvial fans like the one of Karaj. The variation of effective stress caused by intersticial water draining could explain such surface deformation. It can also be noticed that some faults act as boundary for these deformation zones and fluid motion. The understanding of this deformation is relevant for groundwater monitoring and urban developement management. It is also necessary for discriminating it from tectonic deformation that also occurs on this zone. Due to the lack of attitude control of satellite ERS-2 since February 2001, the last images acquired could not be combined with the former acquisitions. Nevertheless, we expect to be able to enrich our set of images in order to map tectonic deformation on a longer period and to monitor in a more continuous way the deformation due to groundwater evolution. This would allow to quantify the permanent and reversible part of this signal.

 

Full paper

 

  Higher level                 Last modified: