Morphodynamics and potential instability of the city of Talca-Chile

Abstract

Chilean cities are preferently concentrated in the Middle Depresion of the central pat of Chile, suffering several types of instabilities principally linked to its geomorphological conformation and to the dynamic of a thick drainage net installed over these. Which determine specific patterns in the city enlargement such as limited altitude construction and therefore a strong horizontal expansion to places that present high levels of seismic instability and hydrologic vulnerability. The objectives are to outline for Talca city some specific problems with the site location, with the aim to consider them in its regulating plans or territorial regulation plans. The first conflict appears with the physical area occupied: geomorphological, hydrological and pedological features. In the first case, the setting is consolidated over dynamic unstable structures, contributing to high risk seismic levels on the second one, the secondary thick drainage Related to the first one, soil features are delivered with instability characteristics due to ist recent formation of alluvial non consolidated materials therefore of great mobility, that make difficult the consolidados of constructions and besides present high phreatic levels, introducing a new variable that limits the human stablishment. The knowledgement of these realities with a common methodology of cartographic criterion of inventary and recognition permit to stablish the so called integrated chartography, not only of detection of the indicated proceses but also the proposals to the planification lines within the context of the territorial regulation of the chilean and latin american urban spaces.