Thesis_Tam Nguyen.pdf

A GEO ENGINEERING STUDY OF THE RED RIVER DELTA CLAY A GIS BASED STUDY OF HANOI LAND SUBSIDENCE, INCLUDING A REVIEW OF THE MONITORING TECHNIQUE INSAR by Nguyen Thi Tam A thesis submitted in partial ful[.]

A GIS-BASED STUDY OF HANOI LAND SUBSIDENCE, INCLUDING A REVIEW OF THE MONITORING TECHNIQUE INSAR by Nguyen Thi Tam A thesis submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geotechnical and Geoenvironmental Engineering Examination Committee: Nationality: Previous Degree: Dr Pham Huy Giao (Chairman) Prof Freek van Der Meer (Co-chairman) Dr Noppadol Phien-wej Vietnamese Bachelor of Science in Geological Science Hanoi University of Science National University Hanoi, Vietnam Scholarship Donor: The BRIDGE Project Asian Institute of Technology School of Engineering and Technology Thailand May 2008 i Acknowledgments I am truly grateful to many individuals who helped me make my research work a challenging, enjoyable and rewarding experience Firstly, I would like to express my deepest gratitude to my advisor, Dr Pham Huy Giao who exceptionally shared his valuable time, excellent support and professional expertise with understanding and patience in the course of my research I would like to express my profound gratitude, utmost sincere appreciation and thanks to my co-advisor, Prof Freek van der Meer for his guidance, valuable suggestions and encouragement in the whole research period especially for his guidance and suggestions related to chapter of my thesis work Special gratitude and utmost thanks is extended to my examination committee members, Dr Noppadol Phien-weij for his valuable suggestions and encouragement given to me from the proposal period that helps direct this thesis in a proper way My sincere gratitude and thanks goes to Dr Mark van der Meijde for his kind supports related to InSAR technique For accomplishing this thesis, I would like to express my thanks to Dr Jirathana Worawattanamateekul, Ms Tran Van Anh, Dr Nguyen Dinh Duong, Mr Tran Anh Tuan, Mr Tran Trong Thang for giving me the valuable data related to InSAR method and GISbased study I also would like to take this opportunity to express my gratitude and utmost thanks to Prof Mai Trong Nhuan who always support and encourage me from my undergraduate study to graduate study period This gives me the confidence to cope with any new challenge My gratitude and thanks is extended to Prof Dang Van Luyen for his kind supports and encouragement during my study in AIT and ITC My sincere thank is extended to all the staffs of Earth Resource Exploration stream specific in ITC for the valuable lectures and sincere helps when I was studying there I would like to extend my thanks to all faculty members, office staffs and friends of Geotechnical and Geoenvironmental Engineering Program for their friendships and continuous encouragements I also gratefully acknowledge the kind assistance given by Hanoi Institute of Building Technology, Hydrogeological Division No Special thanks go to Dr Tran Thi Ha, Mr Dang Tran Trung, and Dr Nguyen Van Dan for providing an amount of useful data used in this thesis I would like to express my deeply gratitude to the Asian Institute of Technology (AIT), International Institute for Geo-Information Science and Earth Observation (ITC) and in particular the BRIDGE project for offering me a full scholarship to study in the Geosystem Exploration and Petroleum Geoengineering program, Geotechnical and Geoenvironmental Engineering Field of Study, AIT with a pleasant semester of exchange study at ITC Without the support of BRIDGE project, I would not have chance to accomplish my MSc study at both well known institutes AIT and ITC Last but not least, my deepest gratitude is for my grandparents, parents, brother, Nguyen Tu Trong, his wife, and especially my two younger sisters Nguyen Thi Dung and Nguyen Thi Hang for their love, sacrifices and continued encouragement during my study All this work is dedicated to you, my two younger sisters, ii Abstract Hanoi is located in the Red River delta, about 100km from the East Sea The city’s population is million and most of water supply comes from groundwater (Giao, 1999) Groundwater exploitation in Hanoi by both public and private wells may have reached 750,000m3/d and the groundwater level has lowered in many locations, say to 35m at Ha Dinh station (Ha, 2007) Over-abstraction of groundwater has caused land subsidence, which in turn affects the upper infrastructures of the city As the network of monitoring station in Hanoi is still limited, a new tool that can monitor land subsidence over a larger area is needed to be studied This study has reviewed on a technique known as Satellite-based Interferometric Synthetic Aperture Radar (InSAR) for monitoring land subsidence Differential InSAR (DInSAR) is a conventional InSAR method, which removes the phase signal caused by relief to yield a differential interferogram in which the signature of surface deformation (in turn land settlement) can be detected Raucoules and Carnec (1999) had generated differential interferograms from ERS-1/2 SAR data and detected signatures of ground vertical movement as much as 15 mm within the time period of 2,5 years; Van Anh (2005) had used JERS-1 SAR data in the period of 1995-1998 and detected the settlement rate in the range of 27-33mm/y The comparison of DInSAR results with the land subsidence records by leveling shows that the settlement from DInSAR was higher than the leveling measurements and the spatial pattern distribution of high settlement rate between them was quite different In addition, this study has proposed a GIS-based procedure to create a land subsidence susceptibility map for Hanoi, which is resulted from overlaying of layers, i.e., surface settlement, Quaternary formation thickness, groundwater drawdown, groundwater dynamic regime, soft clay distribution, population density, and distribution of industrial areas A weighted scale from to was proposed and assigned to each layer The suitability map is classified into four susceptibility zones of occurring land subsidence: the very high susceptibility zone is in the centre of southern Hanoi area; the high susceptibility zone is in the southwestern Hanoi area, the medium susceptibility zone is in the middle of southnorth Hanoi area; and the low susceptibility zone is in the northern Hanoi area iii Table of Contents Chapter Title Page Title Page Acknowledgements Abstract Table of Contents List of Tables List of Figures List of Illustrations i ii iii iv v vi viii Introduction 1.1 Problem statement 1.2 Objectives of the study 1.3 Scopes of the study Literature Review 2.1 Backgrounds on land subsidence 2.2 Study area 2.3 Basics of Geographical Information System (GIS) 2.4 Basics of Remote Sensing 2.5 From SAR data to Information: Status, Trends and Future (Rudiger Gens, 2006) 2.6 Important Parameters of SAR Satellite System 1 2 Methodology 3.1 Flowchart carried out the thesis work 3.2 A study of InSAR technique in monitoring land subsidence 3.3 Land subsidence susceptibility zonation InSAR technique and its application for Hanoi land subsidence 4.1 Introduction 4.2 Interferometry Synthetic Aperture Radar (InSAR) 4.3 Detection of Hanoi land subsidence by DInSAR method 4.4 Groundwater level lowering and subsidence appearance in Hanoi area 4.5 Comparisons and Discussions 4.6 Limitations of DInSAR method, a step to PSInSAR technique Land subsidence susceptibility zonation 5.1 Introduction 5.2 The factors control Hanoi land subsidence 5.3 Weighted overlay the land subsidence control factors 5.4 Concluded remarks Conclusions and Recommendations 6.1 Conclusions 6.2 Recommendations References Appendixes iv 3 13 15 16 17 19 19 19 22 26 26 26 28 30 30 32 35 35 35 37 38 39 39 39 41 46 Table 2.1 4.1 4.2a 4.2b List of Tables Title Comparison of different means for measuring subsidence (Worawattanamateekul, 2006) Used interferometric SAR combinations from ERS1/ERS2 data on Hanoi and perpendicular components of the baselines in meters (Raucoles and Carnec, 1999) Descriptions of five images of JERS-1 (Anh, 2005) 5.1 Characteristics of the produced (SLC) and (MLI) data from four data sets (Anh, 2005) Two sets of leveling survey data (Anh, 2005) Comparison of leveling data with DInSAR data The annual rate of subsidence estimated by DInSAR analyses were sampled at ten benchmarks (Updated from Anh, 2005 and Toan, 2005) Settlement and drawdown data at land subsidence monitoring station (HIBT, 2004) The thickness of soft clay at some area inside Hanoi 5.2 5.3 Assigned weight of soft clay distribution factor Assigned weight for population density factor 4.3 4.4 4.5 v Page 52 53 53 54 55 56 57 58 58 58 Figure 1.1 2.1 2.2 2.3 2.4a 2.4b 2.5 2.6a 2.6b 2.6c 2.6d 2.7 2.8 2.9 2.10 2.11a 2.11b 2.11c 2.11d 4.1a 4.1b 4.1c 4.2 4.3 4.4 4.5 List of Figures Title (a) Vietnam; (b) Study area, Hanoi, the capital of Vietnam Total stress, effective stress, and fluid pressure (pore water pressure) on an arbitrary plane through a saturated porous medium (after Freeze and Cherry, 1979) General schematic of a pipe extensometer for site-specific measurement of subsidence Above-ground portion of a cable extensometer with recording equipment Lithofacies section of the Red River Delta (W-E) (Nghi et al, 1991) Lithofacies section of the Red River Delta (S-N) (Nghi et al, 1991) Hanoi subsoil profiles (Hien, 2006 Ha Noi aquifer system (Giao and Ovaskainen, 2000) Hydrogeological map of Hanoi area (K2, 2003) Page 59 59 60 60 61 61 62 62 63 Sketch of Hanoi aquifer system (HWBC, 2000) National groundwater monitoring stations and Hanoi groundwater monitoring stations Locations of Well Fields and Land Subsidence Monitoring Stations in Hanoi (Toan, 2005) 64 65 Well fields in Hanoi city: (a) well field; (b) Groundwater exploitation (Anh, 2005) A conceptual GIS Model showing thematic layers Electromagnetic energy has been classified by wavelength and arranged to form the electromagnetic spectrum SAR system from a satellite InSAR imaging geometry Geometric parameters of a satellite interferometric SAR system Geometry of a satellite InSAR system Geocoded unwrapped interferogram resulting from the fusion of the interferograms 23925/4753, 4252/4753,24426/4753, and 4252/24426 (Raucoules and Carnec, 1999) Interferograms 24426/7258 and 4753/7258 with possible movement related features The phase variation is about half fringe i.e 15 mm movement (during a months period) (Raucoules and Carnec, 1999) Interferograms 24426/15274 and 7258/15274 (2 years apart) A possible vertical movement (less than half fringe) is located (Raucoules and Carnec, 1999) Interferograms and coherence maps generated from Image (1995/09/18), Image (1995/08/05) and Image (1998/09/22) Differential interferogram Δφ One fringe corresponds to the change of distance along the line of sight by one half of wavelength (11.76 cm) (Anh, 2005) Estimation of total subsidence during the period 1995-1998 based on the assumption that there has been no horizontal displacement (Anh, 2005) Subsidence along the profiles X-X’ and Y-Y’ given in Figure 4.4 (a) Profile X-X’ across the area A, (b) Profile Y-Y’ across the areas B and C 67 vi 66 68 68 68 69 69 70 71 72 72 73 74 75 76 4.6 4.7 4.8 4.9 4.10a 4.10b 4.11 4.12a 4.12b 4.13 5.1 Distance is measured in meters from the bank west of the Red River towards N60°E direction (Anh, 2005 Annual rate of subsidence during the period 1995-1998 (Anh, 2005) Well field locations and respective discharge capacity Three dimensional drawdown view of Hanoi area, showing the cone of depression (data provided by K2, 2004) Land subsidence map period 1988-1995: (a) total view of Hanoi, (b) areas detected land subsidence (K2, 2001) Surface settlement at 10 land subsidence monitoring stations (data provided by HIBT, 2004) Settlement rate at 10 land subsidence monitoring stations Overlaying settlement data at monitoring stations on ERS differential interferogram Locations of benchmarks listed in Table 4.3 Numerals represent annual rates of subsidence revealed by leveling survey in the period 1994-1995 Leveling settlement data versus DInSAR settlement data Overlaying settlement rate at monitoring stations on JERS-1 differental interferogram Land subsidence inventory map period 1988-1995: (1) settlement rate is less than 10mm/y, (2) settlement rate is between 10-20mm/y, (3) settlement rate is between 20-40 mm/y (updated after K2, 2001) 5.2a 5.2b Quaternary thickness contour map over Hanoi area 5.2c Quaternary thickness interpolated map over Hanoi area (kriging interpolation from 77 observation boreholes Drawdown map over Hanoi area Drawdown interpolated map Groundwater dynamic distribution over Hanoi area Index map of groundwater dynamic regime factor: (0) natural groundwater dynamic zone; (1) medium destructive groundwater dynamic zone; (2) strongly destructive groundwater dynamic zone Soft clay distribution over Hanoi area (update data from Toan, 2005): (0) no data; (1) area without clay; (2) area distributed by soft clay Population densities over Hanoi area Industrial zones in Hanoi city, buffered map by km Land subsidence monitoring locations, well field locations Weighted overlay computation Weighted overlay of layers (drawdown, quaternary sediment thickness and land subsidence inventory map); (1) Low susceptibility of occurring land subsidence; (2) Medium susceptibility of occurring land subsidence; (3) High susceptibility of occurring land subsidence; (4) Very high susceptibility of occurring land subsidence Weighted overlay seven factors controlling Hanoi Land subsidence Weighted overlay result of factors (including soft clay, quaternary sediment thickness, drawdown, population density, groundwater dynamic regime factor, land subsidence inventory map) controlling Hanoi land subsidence 5.3a 5.3b 5.4a 5.4b 5.5 5.6 5.7 5.8 5.9 5.10 5.11 5.12 3D view of quaternary sediment distribution over Hanoi area vii 76 77 77 78 79 79 80 81 82 82 83 84 85 83 84 85 86 87 88 89 90 91 91 92 93 94 List of Illustrations Term Description DEM ERS ESA GPS HIBT HWBC InSAR JERS-1 JICA K2 LOS PS PSC PSI SAR SLC SRTM-(X) Digital Elevation Model European Remote Sensing satellite European Space Agency Global Positioning System Hanoi Institute of Building Technology Hanoi Water Business Company Interferometric Synthetic Aperture Radar (also radar interferometry Japanese Earth Resource Satellite – Japan International Cooperation Agency Hydrogeological Division No Line of Sight direction of the satellite (also slant range direction) Permanent Scatterer Permanent Scatterer Candidate Permanent Scatterer Interferometry Synthetic Aperture Radar Single Look Complex Shuttle Radar Topography Mission (X stand for X- band of the microwave wavelength viii Chapter INTRODUCTION 1.1 Problem statement Ground deformation, and in particular subsidence, are major issues in terms of damage to infrastructures, implying remarkable costs for prevention and compensation The causes of subsidence phenomena can be numerous; among others ground settlement due to liquid extraction is very popular over the world Aiming at an effective risk management, monitoring techniques and integrated research are required in order to allow a better knowledge of ground deformation phenomena and of their possible evolution Hanoi (figure 1.1), the Capital of Vietnam, is located in the Red River delta, a low-lying area in northeastern country, around 100km from the Gulf of Tonkin, the East Sea The city is the centre of education, culture, economy, trade, travel, transportation of Vietnam The development along with the continuously increasing of population requires the increasing consumption of water resources The city’s population is million and the water for domestic and industrial use in Hanoi comes from wells located within and around the city The groundwater exploitation capacity has risen from 40,000m3/d in the 1950s to 750,000 m3/d currently and is expected to exceed million m3/d in the 2020s Overexploitation of groundwater in Hanoi is suspected to cause land subsidence which in turn may affect the upper infrastructures of the city Hanoi area is underlain by young quaternary sediments including organic and inorganic clays, silts, peats that are highly compressible, will in turn manifest the vulnerability of land subsidence phenomenon in Hanoi area The more the compressible of the subsoil the higher the susceptibility of occurring land subsidence As the elevation of most part of the city is lower comparing to the Red River water level, the city was isolated by the embankment and dam systems, and land subsidence problem becomes more serious The investigation of land subsidence in Hanoi area is still sporadic and in its infancy stage with very few monitoring data of good quality The techniques used to monitoring land subsidence in Hanoi area are poor and were not enough to reflect the reality status of Hanoi land subsidence The techniques based on revisiting ground-based benchmarks such as optical leveling or Global Positioning System (GPS) generally offer precise measurements but limited by their spatially sparse and infrequent sampling As a result, the ground-based bench-marks over Hanoi area are very few; there are only 10 land subsidence monitoring stations for now Denser and more frequent subsidence observations are essential for understanding the ground subsidence distribution over Hanoi area Satellite-based Interferometric Synthetic Aperture Radar (InSAR), developing during 1980-1990s, offers the potential for acquiring displacement observations over wide areas with a high resolution both spatially and temporally Permanent Scatterer Interferometric Synthetic Aperture Radar (PSInSAR) is a newly developed surface displacement observation technique based on conventional InSAR It is an operational tool for precise ground deformation mapping on a sparse grid of phase stable radar targets, acting as a “natural” geodetic network This technique identifies, estimates and removes atmospheric distortions, leaving the PS displacement as the only contribution to the signal phase shift SAR data and, in particular, PSInSAR can be very useful for geological hazard assessment (e.g landslides, subsidence, earthquakes) This approach provides fast and updatable data acquisition over large areas, and can be integrated with conventional methods of investigation (e.g field surveys, air photos interpretation) Of particular interest is the possibility to combine deformation measurements with geological data in a geographical information system (GIS) Unfortunately, PSInSAR even InSAR techniques are still not common used in Southeastern countries especially in Vietnam This technique requires the user with good knowledge of interferometry, it requires data archive, time and experience for data processing The complex atmospheric conditions, the unavailable data, in additions with lack of InSAR experts are the main limitations for applying this technique in Vietnam However many challenges, to reach and explore about the new and feasibility quantitative method for land subsidence assessment, this study will review on the theory of PSInSAR technique with possible application for monitoring and assessing Hanoi land subsidence as a primary work As the PSInSAR technique is not yet being used for measuring Hanoi land subsidence, an effective solution is the integration of the previous studies and available data of geographical settings; geological settings; hydrological settings; groundwater extraction; geotechnical settings, and the land use information then identify the significant factors that control Hanoi land subsidence using Geographical Information System (GIS) to produce the integrated assessment of land subsidence susceptibility for Hanoi area 1.2 Objectives of the study 1) To review on a technique known as Satellite-based Interferometric Synthetic Aperture Radar (InSAR) for monitoring land subsidence 2) To create a land subsidence susceptibility map for Hanoi area based on the results of previous studies, combining with updated data 1.3 Scopes of the study To perform the objectives of this study, the following scopes need to be done: 1) To overview InSAR technique in monitoring land subsidence; the initial studies resulted on Hanoi land subsidence using DInSAR technique obtained by Raucoules and Carnec (1999) and Anh (2005) need to be revisited in a comparison with some ground monitoring record to determine the ground subsidence for Hanoi area 2) To review the previous and existing studies on Hanoi land subsidence; collection of update information 3) Building a land subsidence database including geological, subsoil, hydrogeological data based on the tools of Exel, Access, Grapher, Rockwork 2006, Map info 80, Arc GIS 9.2 4) Proposing a procedure to create a land subsidence susceptibility map for Hanoi area Figure 5.1 Land subsidence inventory map period 1988-1995: (1) settlement rate is less than 10mm/y, (2) settlement rate is between 10-20mm/y, (3) settlement rate is between 2040 mm/y (updated after K2, 2001) 83 Figure 5.2a Quaternary thickness contour map over Hanoi area 84 Figure 5.2b three dimensional view of quaternary sediment distribution over Hanoi area 85 Figure 5.2c Quaternary thickness interpolated map over Hanoi area (kriging interpolation from 77 observation boreholes) 83 Figure 5.3a Drawdown map over Hanoi area (Data provided by K2) 84 Figure 5.3b Drawdown interpolated map (unit is meter) 85 Figure 5.4a Groundwater dynamic distribution over Hanoi area (K2, 2003) 86 Figure 5.4b Index map of groundwater dynamic regime factor: (0) natural groundwater dynamic zone; (1) medium destructive groundwater dynamic zone; (2) strongly destructive groundwater dynamic zone 87 Figure 5.5 Soft clay distribution over Hanoi area (update data from Toan, 2005): (0) no data; (1) area without clay; (2) area distributed by soft clay 88 Figure 5.6 Population densities over Hanoi area 89 Figure 5.7 Industrial zones in Hanoi city, buffered map by km 90 Figure 5.8 Land subsidence monitoring locations, well field locations Figure 5.9 Weighted overlay computation 91 Figure 5.10 Weighted overlay of layers (drawdown, quaternary sediment thickness and land subsidence inventory map); (1) Low susceptibility of occurring land subsidence; (2) Medium susceptibility of occurring land subsidence; (3) High susceptibility of occurring land subsidence; (4) Very high susceptibility of occurring land subsidence 92 Figure 5.11 Weighted overlay seven factors controlling Hanoi Land subsidence 93 Figure 5.12 Weighted overlay result of factors (including soft clay, quaternary sediment thickness, drawdown, population density, groundwater dynamic regime factor, land subsidence inventory map) controlling Hanoi land subsidence 94