Subsidence in Celaya, Guanajuato, Central Mexico: implications for groundwater extraction and the neotectonic regime

Abstract

The problem of land subsidence and formation of earth fissures, in most cases reported in different parts of the world, has been exclusively interpreted as a result of excessive groundwater extraction. In the Celaya, Guanajuato region, geologic and hydrologic information indicates that the process causing this subsidence and earth fissuring is complex. The dynamic tectonics of the area located in an active seismic zone where thermal springs with temperatures above 40 °C are present, should influence the process. The geologic evidence indicates that the formation of new earth fissures is controlled by the geologic-structural framework that existed previous to the deposition of the alluvial valley infill. Uncontrolled groundwater extraction constitutes an important factor because it modifies the initial saturation of the valley infill material and enhances (reactivates) pre-existing structural features, producing a loss of pore water pressure. Most earth fissures in the Celaya area are related to pre-existing structural features.