scholarly journals Factors that condition physical vulnerability to ground fracturing in Mexico City

2020 ◽  
Vol 382 ◽  
pp. 571-576
Author(s):  
Dora Carreon-Freyre ◽  
Raul I. Gutierrez-Calderon ◽  
Mariano Cerca ◽  
Carlos F. Alcantara-Duran
Keyword(s):  
Mexico City ◽  
Urban Infrastructure ◽  
Vulnerability Index ◽  
Deterministic Approach ◽  
Physical Vulnerability ◽  
Work Factors ◽  
Mitigation Costs ◽  
Physical Variables ◽  
Geological Phenomenon

Abstract. In spite of subsidence being a well-studied geological phenomenon in Mexico City, its effects and risks for urban infrastructure and inhabitants have been neglected. Damage in the short, medium and long term implies maintenance and important mitigation costs. There are not systematic studies that address methodologies for the estimation of physical vulnerability of the geological media to fracture. In this work, factors conditioning the deformation and susceptibility to fracturing are analyzed using a deterministic approach. The identified physical variables were mapped, measured and integrated into a database that allowed for an adequate correlation of the parameters that condition fractures spatial distribution. A methodology for estimating a vulnerability index to fracturing (VIF) useful for decision making is proposed in this work.

Sentinel-1 InSAR survey to constrain subsidence-induced surface faulting and quantify its induced risk in major cities of central Mexico

2021 ◽  
Author(s):  
Francesca Cigna ◽  
Deodato Tapete
Keyword(s):  
Risk Assessment ◽  
Mexico City ◽  
Land Subsidence ◽  
Groundwater Resources ◽  
Urban Infrastructure ◽  
Capital City ◽  
Transport Infrastructure ◽  
Central Mexico ◽  
Groundwater Exploitation ◽  
Persistent Scatterers

<p>Several major cities in central Mexico suffer from aquifer depletion and land subsidence driven by overexploitation of groundwater resources to address increasing water demands for domestic, industrial and agricultural use. Ground settlement often combines with surface faulting, fracturing and cracking, causing damage to urban infrastructure, including private properties and public buildings, as well as transport infrastructure and utility networks. These impacts are very common and induce significant economic loss, thus representing a key topic of concern for inhabitants, authorities and stakeholders. This work provides an Interferometric Synthetic Aperture Radar (InSAR) 2014-2020 survey based on parallel processing of Sentinel-1 IW big data stacks within ESA’s Geohazards Exploitation Platform (GEP), using hosted on-demand services based on multi-temporal InSAR methods including Small BAseline Subset (SBAS) and Persistent Scatterers Interferometry (PSI). Surface faulting hazard is constrained based on differential settlement observations and the estimation of angular distortions that are produced on urban structures. The assessment of the E-W deformation field and computation of horizontal strain also allows the identification of hogging (tensile strain or extension) and sagging (compression) zones, where building cracks are more likely to develop at the highest and lowest elevations, respectively. Sentinel-1 observations agree with in-situ observations, static GPS surveying and continuous GNSS monitoring data. The distribution of field surveyed faults and fissures compared with maps of angular distortions and strain also enables the identification of areas with potentially yet-unmapped and incipient ground discontinuities. A methodology to embed such information into the process of surface faulting risk assessment for urban infrastructure is proposed and demonstrated for the Metropolitan Area of Mexico City [1], one of the fastest sinking cities globally (up to 40 cm/year subsidence rates), and the state of Aguascalientes [2], where a structurally-controlled fast subsidence process (over 10 cm/year rates) affects the namesake valley and capital city. The value of this research lies in the demonstration that InSAR data and their derived parameters are not only essential to constrain the deformation processes, but can also serve as a direct input into risk assessment to quantify (at least, as a lower bound) the percentage of properties and population at risk, and monitor how this percentage may change as land subsidence evolves.</p><p>[1] Cigna F., Tapete D. 2021. Present-day land subsidence rates, surface faulting hazard and risk in Mexico City with 2014–2020 Sentinel-1 IW InSAR. <em>Remote Sens. Environ.</em> 253, 1-19, doi:10.1016/j.rse.2020.112161</p><p>[2] Cigna F., Tapete D. 2021. Satellite InSAR survey of structurally-controlled land subsidence due to groundwater exploitation in the Aguascalientes Valley, Mexico. <em>Remote Sens. Environ.</em> 254, 1-23, doi:10.1016/j.rse.2020.112254</p>

scholarly journals КАРАКАЛПАКСКИЙ ПОСТОЯЛЫЙ ДВОР ШАРБАҚ

2021 ◽  
pp. 287-293
Author(s):  
Г.А Акимниязова
Keyword(s):  
20Th Century ◽  
Social Life ◽  
Urban Infrastructure ◽  
Short Stay ◽  
The Social ◽  
Economic Ties ◽  
The City

Развитие торговли и экономических связей привело к необходимости строительства специальных заведений, предназначенных для торговцев, путников, с помещениями для вьючных животных. Это в свою очередь привело к появлению постоялых дворов. У каракалпаков постоялый двор назывался шарбақ. Он были двух видов: для кратковременного пребывания, расположенный в черте города недалеко от базара, и долговременного пребывания, устанавливавшийся при въезде в город. Второй из них предпочитали путешествующие издалека. Посетители же первых постоялых дворов останавливались в нем для разгрузки привезенного для продажи товара, реализовав который в течение дня, покидали заведение. Функции шарбақ заключались не только в предоставлении приюта, возможности отдыха, размещения товаров и животных, но и в общении, обмене новостями. В базарные дни сюда стекались жители со всей округи для того, чтобы узнать последние новости. Для старшего поколения шарбақ был, в первую очередь местом проведения досуга. Постоялый двор играл важную роль в жизни каракалпаков. Об этом свидетельствует их количество. К середине XX века постоялый двор начинает терять свою значимость в связи с развитием городской инфраструктуры и появлением гостиниц. The development of economic ties entailed arranging special establishments for traders and travelers, with premises for beasts of burden. This resulted in the construction of hostelries. The Karakalpaks called them sharbak. There were two types of sharbaks: located within the city near the bazaar, intended for a short stay, and installed at the entrance of the city for the long-term visitors. Travelers from far away preferred the second type. Guests of the first type of hostelries usually stayed there just to unload the goods and sell them at the bazaar during the day. The sharbaks not only provided shelter, recreation, and accommodation of goods and animals, but also served as a place for communication and news exchange. On market days, residents from all over the area flocked there to find out the latest news. For the older generation, sharbak was a place of leisure. The hostelry played an important role in the social life of the Karakalpaks, which is evidenced by their large number. By the middle of the 20th century, the sharbak began to lose its significance due to the development of urban infrastructure and modern hotels

scholarly journals An Assessment of Social and Physical Vulnerability to Hydroclimate Extremes in Appalachia

2021 ◽  
Author(s):  
Leah R. Handwerger ◽  
Jennifer R. Runkle ◽  
Ronald Leeper ◽  
Elizabeth Shay ◽  
Kara Dempsey ◽  
...  
Keyword(s):  
Social Vulnerability ◽  
Scientific Community ◽  
Vulnerability Index ◽  
Precipitation Variability ◽  
Mitigation Strategies ◽  
Climate Projections ◽  
Social Vulnerability Index ◽  
Physical Vulnerability ◽  
Vulnerable Communities ◽  
Vulnerability Indicators

Abstract Appalachia is a cultural region in the southern and central Appalachian Mountains that lags behind the nation in several social vulnerability indicators. Climate projections over this region indicate that precipitation variability will increase in both severity and frequency in future decades, suggesting that the occurrence of natural hazards related to hydroclimate extremes will also increase. The objective of this study was to investigate the spatiotemporal patterns of drought and precipitation and determine how trends overlap with vulnerable communities across Appalachia. The study utilized trend analysis through Mann-Kendall calculations and a Social Vulnerability Index, resulting in a bivariate map that displays areas most susceptible to adverse effects from hydroclimate extremes. Results show the southwestern portion of the region as most vulnerable to increased precipitation, and the central-southeast most vulnerable to an increase in drought-precipitation variability. This study is among the first to utilize the boundaries defined by the Appalachian Regional Commission from a climatological perspective, allowing findings to reach audiences outside the scientific community and bring more effective mitigation strategies that span from the local to federal levels.

scholarly journals GPS derived ground motions (2005–2014) within the Gulf of Mexico region referred to a stable Gulf of Mexico reference frame

2015 ◽  
Vol 3 (11) ◽  
pp. 6651-6688
Author(s):  
J. Yu ◽  
G. Wang
Keyword(s):  
Gulf Of Mexico ◽  
Reference Frame ◽  
Mexico City ◽  
Ground Motions ◽  
Local Reference Frame ◽  
Local Reference ◽  
Houston Area ◽  
Gps Observations ◽  
Southeastern Louisiana

Abstract. This study investigates current ground motions derived from the GPS geodesy infrastructure in the Gulf of Mexico region. The positions and velocity vectors of 161 continuous GPS (CGPS) stations are presented with respect to a newly established local reference frame, the Stable Gulf of Mexico Reference Frame (SGOMRF). Thirteen long-term (> 5 years) CGPS are used to realize the local reference frame. The root-mean-square (RMS) of the velocities of the 13 SGOMRF reference stations achieves 0.2 mm yr−1 in the horizontal and 0.3 mm yr−1 in the vertical directions. GPS observations presented in this study indicate significant land subsidence in the coastal area of southeastern Louisiana, the greater Houston metropolitan area, and two cities in Mexico (Aguascalientes and Mexico City). The most rapid subsidence is recorded at the Mexico City International airport, which is up to 26.6 cm yr−1 (2008–2014). Significant spatial variation of subsidence rates is observed in both Mexico City and the Houston area. The overall subsidence rate in the Houston area is decreasing. GPS observations in southeastern Louisiana indicate minor (4.0–6.0 mm yr−1) but consistent subsidence over time and space. This poses a potential threat to the safety of costal infrastructure in the long-term.

Can land subsidence be monitored with ambient seismic auto-correlations?

2021 ◽  
Author(s):  
Laura Ermert ◽  
Marine Denolle ◽  
Enrique Cabral Cano ◽  
Estelle Chaussard ◽  
Dario Solano Rojas
Keyword(s):  
Ambient Noise ◽  
Seismic Velocity ◽  
Urban Infrastructure ◽  
Temporal Correlations ◽  
Long Term Effect ◽  
Seismic Velocity Changes ◽  
Subsurface Layers ◽  
Velocity Changes ◽  
Seasonal Oscillations

<p>Mexico City has been undergoing rapid subsidence for more than 100 years due to groundwater extraction. During the 2010s, rates surpassing 30 centimeters/year were observed by satellite geodetic measurements. Not only does this subsidence pose grave challenges for buildings, urban infrastructure, and water management, but it also changes the seismic response of the affected subsurface layers and thereby alters the seismic hazard in the metropolis that has seen devastating site effects both in the 1985 Michoacan and 2017 Puebla earthquake. We use data and numerical modeling of ambient noise auto-correlations to gain a better insight into the subsidence process through ambient noise techniques.</p><p>We establish a baseline for the long-term and seasonal variations of seismic velocity near the basin from long-term recordings of the Geoscope station UNM, located at the Universidad Nacional Autónoma de México in the geotechnical hill zone. We further study temporary recordings from the MASE array (MASE (2007): Meso America Subduction Experiment. Caltech. Dataset. doi:10.7909/C3RN35SP) to see how subsidence and other factors may influence seismic velocity in the geotechnical hill, transition, and lake zones.</p><p>We find that seasonal oscillations and a strong, rapid velocity drop coincident with the 2017 Puebla earthquake overlay a multi-year increasing trend in seismic velocity. We cautiously interpret the multi-year increase as a long-term effect of subsidence. We further study the temporal correlations of seismic velocity changes with other environmental time series like precipitation, and model auto-correlations in order to improve our understanding of their composition and sensitivity.</p>

The Modern City

2009 ◽  
Author(s):  
DIANE E. DAVIS
Keyword(s):  
Twentieth Century ◽  
Mexico City ◽  
Political Alliances ◽  
The Social ◽  
Shifting Balance ◽  
History Of ◽  
The Rich ◽  
The City ◽  
Rich History

What constitutes modern Mexico? Is there a clear distinction between the historic and modern Mexico City? And if there are, does this distinctions hold up throughout the twentieth century, when what is apparent is a mix of legacies coexisting overtime? This chapter discusses the semiotics of history and modernity. It discusses the struggle of the Mexico City to find its own image including its struggle to preserve historic buildings amidst the differing political alliances that either promote change or preserve the past. However, past is not a single entity, hence if the preservation of the rich history of Mexico is pursued, the question arises as to what periods of history represented in the city are to be favoured in its future development. In this chapter, the focus is on the paradoxes of the Torre Bicentenario and on the pressures to preserve Mexico’s past, the ways they have been juxtaposed against the plans for its future and how the balance of these views has shifted over time. It determines the key actors and the institutions who have embraced history as opposed to progress, identifies the set of forces that dominated in the city’s twentieth-century history, and assesses the long-term implications of the shifting balance for the social, spatial and built environmental character of the city. The chapter ends with a discussion on the current role played by the cultural and historical authorities in determining the fate of the city.

scholarly journals Long-Term Efficiency of Catalytic Converters Operating in Mexico City

2001 ◽  
Vol 51 (5) ◽  
pp. 725-732 ◽  
Author(s):  
Luis Díaz ◽  
Isaac Schifter ◽  
René Rodriguez ◽  
Sergio Avalos ◽  
Gabriel López ◽  
...  
Keyword(s):  
Mexico City ◽  
Catalytic Converters

scholarly journals GPS-derived ground deformation (2005–2014) within the Gulf of Mexico region referred to a stable Gulf of Mexico reference frame

2016 ◽  
Vol 16 (7) ◽  
pp. 1583-1602 ◽  
Author(s):  
Jiangbo Yu ◽  
Guoquan Wang
Keyword(s):  
Gulf Of Mexico ◽  
Reference Frame ◽  
Mexico City ◽  
Ground Deformation ◽  
Local Reference Frame ◽  
Subsidence Rate ◽  
Local Reference ◽  
Houston Area ◽  
Southeastern Louisiana

Abstract. This study investigates current ground deformation derived from the GPS geodesy infrastructure in the Gulf of Mexico region. The positions and velocity vectors of 161 continuous GPS (CGPS) stations are presented with respect to a newly established local reference frame, the Stable Gulf of Mexico Reference Frame (SGOMRF). Thirteen long-term (> 5 years) CGPS are used to realize the local reference frame. The root mean square (RMS) of the velocities of the 13 SGOMRF reference stations achieves 0.2 mm yr−1 in the horizontal and 0.3 mm yr−1 in the vertical directions. GPS observations presented in this study indicate significant land subsidence in the coastal area of southeastern Louisiana, the greater Houston metropolitan area, and two cities in Mexico (Aguascalientes and Mexico City). The most rapid subsidence is recorded at the Mexico City International airport, which is up to 26.6 cm yr−1 (2008–2014). Significant spatial variation of subsidence rates is observed in both Mexico City and the Houston area. The overall subsidence rate in the Houston area is decreasing. The subsidence rate in southeastern Louisiana is relatively smaller (4.0–6.0 mm yr−1) but tends to be steady over time. This poses a potential threat to the safety of coastal infrastructure in the long-term.

Patient Characteristics Associated With the Need for Long-Term Treatment in a Child Psychiatry Hospital After the Earthquake in Mexico City

2020 ◽  
pp. 1-3
Author(s):  
Rosa-Elena Ulloa ◽  
Emmanuel Sarmiento
Keyword(s):  
Mexico City ◽  
Child Psychiatry ◽  
Clinical Characteristics ◽  
Patient Characteristics ◽  
Term Treatment ◽  
Health Programs ◽  
Baseline Assessment ◽  
Long Term Treatment ◽  
Mental Health Programs

ABSTRACT Objective: The aim of this study is to determine the demographic and clinical characteristics associated with the need for long-term treatment in a child psychiatry facility. Method: Demographic characteristics, diagnosis, source of referral, time elapsed between the earthquake and the request for care, and the treatment prescribed in the baseline assessment were compared between a group of subjects that required long-term treatment (LTT) and a group that was discharged after a brief intervention (D). Results: A total of 171 patients were seen, and 27% of the subjects required LTT. In general, these subjects were younger, referred from highly affected areas, presented a delay in seeking care, and were mainly diagnosed with anxiety and stress-related disorders. Conclusions: These findings suggest the need for research regarding the design of mental health programs for the early detection of psychopathology after natural disasters in children and adolescents.

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