Land Subsidence induced by groundwater extraction an associated ground fracturing in central Mexico

Transcription

1 LASER: LAnd Subsidence Induced by Fluid ExtRaction 14th November, Madrid, Spain Land Subsidence induced by groundwater extraction an associated ground fracturing in central Mexico Dora Carreón Freyre (LAMG-UNAM), Mariano Cerca (LAMG-UNAM), Raúl Gutierrez Calderón (CERG-CDMX) Laboratorio de Mecánica de Geosistemas (LAMG) Centro de Geociencias, Campus UNAM Juriquilla Querétaro

2 Overview 1. The UNESCO Working Group on Land Subsidence 2. Case studies in Central Mexico l Geological. Regional Faulting l The CENAPRED Mexico City Project 3. Final remarks

3 1. The UNESCO Working Group on Land Subsidence (Galloway et al., 2016) l Land Subsidence is globally prevalent and because much of it is related to hydrological processes affected by human development of local land and water resources, Land Subsidence was included in the UNESCO programme of the International Hydrological Decade (IHD), and an ad hoc working group on land subsidence was formed. l In 1975 subsidence was retained under the framework of the UNESCO IHP (subproject 8.4: Investigation of Land Subsidence due to Groundwater Exploitation ), and UNESCO IHP formerly codified the Working Group on Land Subsidence (WGLS). Probably in 2018 the WGLS becomes the Initiative on Land Subsidence with a broad projection worldwide and stronger support within the International Hydrological Program.

4 1. The UNESCO Working Group on Land Subsidence The Mission of the WGLS: Enhance scientific/technical knowledge needed to identify and characterize hazards related to natural and anthropogenic subsidence Promote/Facilitate international exchange of information to support sustainable water-resources development in subsidence prone areas regarding design, implementation and evaluation of risk assessments and mitigation measures definition of effective resource-management strategies

5 1. The UNESCO Working Group on Land Subsidence l Enhance scientific/technical knowledge During the IHD, UNESCO and the ad hoc WGLS convened the 1st International Symposium on Land Subsidence in 1969 in Tokyo, Japan. In collaboration with UNESCO IHP, IAHS, and other scientific organizations, the WGLS has convened 8 more International Symposia on Land Subsidence in different countries in Asia, Europe and North America. The 9 published symposia proceedings and 2 companion books constitute an important source of global subsidence research and case studies during the past 45 years, covering both anthropogenic and natural subsidence processes: 1. Tokyo, 2. Anaheim; 3. Venice; 4. Houston; 5. The Hague; 6. Ravenna 7. Shanghai; 8. Queretaro; 9. Nagoya The Netherlands 2020

6 1. The UNESCO Working Group on Land Subsidence l Who we are? l Currently, the WGLS comprises 19 subsidence experts from 10 countries, and a UNESCO IHP representative. China-Taiwan, Egypt, Indonesia, Italy, Japan, Mexico, Spain, The Netherlands, Polland, USA l l l The WGLS is largely supported by labor and travel expenses covered by the member/observer institutions. Visit our website: If you are are actively engaged in land subsidence studies and interested in participating in the WGLS please us at unesco.landsubsidence@gmail.com.

7 1. The UNESCO Working Group on Land Subsidence l Annual Meeting in Puerto Vallarta, Jalisco MEXICO November 2016

8 l USA TMVB l Basin and range ext Two volcanic extensional episodes SMO Riolythic, Basin and Range TMVB Basaltic, Andestic, Intra-arc

9 Aguascalientes León Querétaro Ameca GuadalajaraCelaya/Bajio México City Morelia Toluca Geological map from Ferrari et al., 2012 l MVB map of Ferrari et al, 2012

10 Major cities of Central Mexico with subsidence problems (dotted circles) are located in inter-volcanic and fault bounded basins within the central Trans-Mexican Volcanic Belt (TMVB). Brown colors indicate Plio-Quaternary volcanic and pyroclastic events, yellow colors indicate volcano-sedimentary and lacustrine Quaternary deposits, red colors indicate intrusive rocks (Geologic map from Ferrari et al., 2007).

11 Mexico City: Geological Land Subsidence and Ground Fracturing Near surface sequences Tensional open fracture without significant vertical displacement Ground fracturing with cm height vertical displacement Geological faulting in pyroclastic deposits

12 City of Queretaro Graben Carreon-Freyre et al., 2015

13 Carreon-Freyre et al., 2016

14 City of Queretaro Piezometric withdrawal (a) , (b) 2012 (a) Carreon-Freyre et al., 2005 (b)

15 Ochoa et al., 2015

16 Aquifer model of Queretaro Carrera et al., 2016

17 Ochoa et al., 2014

18 Fracturamiento Superficie del terreno Fracturamiento Superficie del terreno despues de la subsidencia ROCA Ciudad de San Luis Potosi, SLP Carreon-Freyre et al., 2009

19 Ciudad de Celaya, Guanajuato Trujillo-Candelaria, 2003

20 Celaya, Guanajuato

21 Guadalajara, Jalisco Ameca and Nextipac areas Rosas-Elguera et al, 2012

22 The Mexico City study case Geologic map of Mexico City (SEGEOMET, 2010) Lacustrine area In the Valley of Mexico Basin

23 Land Subsidence first reported in 1925 SACM 2000, Conagua 2015

24 Mexico City study case. Iztapalapa Geological Risk Assesment: Risk =Hazard x Vulnerability Center of Evaluation of Geological Risk (CERG) Iztapalapa, Mexico City

25 Map of geological risk related with LS and Fracturing in Iztapalapa

26 Mexico City: Geological The Chalco Area (a) Trace of the Falla Cuautlapan that appeared in June Yellow arrows show the direction of displacements in the surface and the zigzag geometry of the fracture; (b) General view of the fracture, the diagram in gray show the raised plains of the fracture and the subsiding surfaces in both sides where water accumulates.

27 Groundwater management in the Metropolitan Mexico City Area (MMCA) Chavez-Guillen, Conagua 2015

28 The Mexico Basin Groundwater management Declining of Groundwater Reserves in Mexico City, Conagua, 2015

29 Conagua 2015

30 Conagua 2015

31 Mapping of fracturing. The CENAPRED Project CENAPRED: Centro Nacional de Prevencion de Desastres (National Center for the Disaster Prevention. Is a part of the National System of Civil Protection in Mexico (SINAPROC) Historical Subsidence in Mexico City (Perez-Centeno, 2009)

32 Mapping of fracturing. The CENAPRED Project

33 3. Final Remarks LS and ground fracturing are multifactor and multi-scale phenomena thar are damaging many cities of central Mexico. The increase of the effective stresses induced by groundwater depletion does not solely explain the propagation of deformation in the subsoil and in the surface. The correlation of geological, mechanical and hydraulic parameters In each study case has suggest a dynamic inter-play between the distribution of deformation in the surface, mechanisms of fracturing and the stress history of the local sequences. In the urban areas groundwater decline modifies the state of stress within high variable stratigraphic units. These changes are strongly conditioned by pre-existing discontinuities (stratigraphic contacts and/or geological faulting) that localize strain mainly in the near surface sequence

34 3. Final Remarks