Hydrogeological characterization of the Plateaus region of the Quito Aquifer System using remote sensing, digital geomorphology, and geophysics

Document Type

Conference Proceeding

Publication Date

9-17-2012

Abstract

Remote sensing techniques can be used in the characterization of landscapes for assessing groundwater resources. Digital terrain analysis has been used broadly for study subsurface geology, especially analysis of topographic features and their relationship to tectonic and structural phenomena. Structural discontinuities such as faults are expressed in a DEM as a linear feature, representing the intersection of a fracture plane and land surface. Besides, lineaments, faults originate morphotectonic structures such as depressions, asymmetric slopes across valleys and ridgelines axis. There are morphological evidences of tectonics that are represented by a point feature that may have a spatial continuity due to the same origin. This could happen especially on soft rocks that do not easily record deformations. Geophysical surveys are especially appropriate for confirming the presence, extent, and orientation of geological lineaments, as well as for detecting the presence of water in the fractures. The use of 2D resistivity profiling is widespread as a tool to identify aquifer layers in sedimentary rocks and volcanic terrains and also to detect water bearing fractures The VLF method has been applied successfully to map the resistivity contrast in fractured zones. Based on the RS lineament mapping, complemented with the digital morphological analysis and geophysics, fracturing patterns were characterized for the Plateaus region of the Quito Aquifer System (QAS). The aquifer is located in the Central Inter-Andean Valley of Ecuador, a region affected by active volcanism and faulting and characterized by basins filled with series of volcanic deposits and primary and reworked sedimentary rocks. By combining our results with those from previous geological studies and hydrogeological data, the impact of topography and fracturing on the hydrogeology of the plateaus was assessed. © 2012 ASCE.

Publication Title

World Environmental and Water Resources Congress 2012: Crossing Boundaries, Proceedings of the 2012 Congress

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