The Toluca Valley Aquifer (TVA) is considered one of the most overexploited aquifers in Mexico because of the high rate of groundwater extraction for supplying urban and industrial water to Mexico City and Toluca City...The Toluca Valley Aquifer (TVA) is considered one of the most overexploited aquifers in Mexico because of the high rate of groundwater extraction for supplying urban and industrial water to Mexico City and Toluca City, which causes land subsidence in urban and suburban areas. In this paper, we propose a multi-temporal analysis that uses persistent scatterer interferometry (PSI) method to evaluate the subsidence processes in Toluca Valley. The PSI results revealed differential movements of the ground of as much as 83 mm/year. A spatial variation of PSI results was identified with respect to previous studies using the conventional Din SAR methodology. The spatial distribution and density suggested the possibility of an expanding trend of subsidence process at north, northeast and east of the TVA, which corresponds to the region with the highest density of pumping wells for industrial and agricultural use.展开更多
Satellite data sets are an asset in global gravity collections;their characteristics vary in coverage and resolution. New collections appear often, and the user must adapt fast to their characteristics. Their use in g...Satellite data sets are an asset in global gravity collections;their characteristics vary in coverage and resolution. New collections appear often, and the user must adapt fast to their characteristics. Their use in geophysical modeling is rapidly increasing;with this in mind we compare two of the most densely populated sets: EIGEN-6C4 and GGMplus. We characterize them in terms of their frequency histograms, Free Air anomalies, power spectrum, and simple Bouguer anomalies. The nature of the digital elevation models used for data reduction is discussed. We conclude that the GGMplus data set offers a better spatial resolution. To evaluate their effect in geophysical modelling, we chose an inland region with a prominent volcanic structure in which we perform 3D inversions of the respective Bouguer anomalies, obtaining density variations that in principle can be associated with the geologic materials and the structure of the volcanic edifice. Model results are analyzed along sections of the inverted data;we conclude that the GGMplus data set offers higher resolution in the cases analyzed.展开更多
文摘The Toluca Valley Aquifer (TVA) is considered one of the most overexploited aquifers in Mexico because of the high rate of groundwater extraction for supplying urban and industrial water to Mexico City and Toluca City, which causes land subsidence in urban and suburban areas. In this paper, we propose a multi-temporal analysis that uses persistent scatterer interferometry (PSI) method to evaluate the subsidence processes in Toluca Valley. The PSI results revealed differential movements of the ground of as much as 83 mm/year. A spatial variation of PSI results was identified with respect to previous studies using the conventional Din SAR methodology. The spatial distribution and density suggested the possibility of an expanding trend of subsidence process at north, northeast and east of the TVA, which corresponds to the region with the highest density of pumping wells for industrial and agricultural use.
文摘Satellite data sets are an asset in global gravity collections;their characteristics vary in coverage and resolution. New collections appear often, and the user must adapt fast to their characteristics. Their use in geophysical modeling is rapidly increasing;with this in mind we compare two of the most densely populated sets: EIGEN-6C4 and GGMplus. We characterize them in terms of their frequency histograms, Free Air anomalies, power spectrum, and simple Bouguer anomalies. The nature of the digital elevation models used for data reduction is discussed. We conclude that the GGMplus data set offers a better spatial resolution. To evaluate their effect in geophysical modelling, we chose an inland region with a prominent volcanic structure in which we perform 3D inversions of the respective Bouguer anomalies, obtaining density variations that in principle can be associated with the geologic materials and the structure of the volcanic edifice. Model results are analyzed along sections of the inverted data;we conclude that the GGMplus data set offers higher resolution in the cases analyzed.
