Long Term Subsidence Analysis and Soil Fracturing Zonation Based on InSAR Time Series Modelling in Northern Zona Metropolitana del Valle de Mexico

Abstract

In this study deformation processes in northern Zona Metropolitana del Valle de Mexico (ZMVM) are evaluated by means of advanced multi-temporal interferometry. ERS and ENVISAT time series, covering approximately an 11-year period (between 1999 and 2010), were produced showing mainly linear subsidence behaviour for almost the entire area under study, but increasing rates that reach up to 285 mm/yr. Important non-linear deformation was identified in certain areas, presumably suggesting interaction between subsidence and other processes. Thus, a methodology for identification of probable fracturing zones based on discrimination and modelling of the non-linear (quadratic function) component is presented. This component was mapped and temporal subsidence evolution profiles were constructed across areas where notable acceleration (maximum of 8 mm/yr2) or deceleration (maximum of −9 mm/yr2) is found. This methodology enables location of potential soil fractures that could impact relevant infrastructure such as the Tunel Emisor Oriente (TEO) (along the structure rates exceed 200 mm/yr). Additionally, subsidence behaviour during wet and dry seasons is tackled in partially urbanized areas. This paper provides useful information for geological risk assessment in the area.

Keywords

• subsidence
• fracturing zonation
• small baseline subset (SBAS)
• ERS
• ENVISAT