three dimensional deformation and strain induced by municipal pumping part 1 analysis of field data a 62 day controlled aquifer test was performed at the site of a new municipal well that penetrates a thick sequence of compressible basin fill deposits in mesquite nevada observation data were acquired from a high precision global positioning system gps network to accompany the water level data from the pumped well and a nearby observation well the purpose of the investigation was to quantify and characterize three dimensional surface deformation and strain associated with cyclic pumping and to evaluate aquifer properties on the basis of these data results indicate that both horizontal 8 mm total displacement with 0 2 mm precision and vertical deformation 12 mm total displacement with 2 mm precision were measuredwithinthefirst22daysofpumpingwithaslowlymigratingoutwardwaveofcompressionalstraininspiteofthefactthat an 83 m brittle unsaturated zone resided over the dynamically active aquifer the hydraulic head and strain data indicate that steady state pumping conditions were likely reached after 35 40 days results also indicate that vertical mechanical rebound occurs after about 35 days even though the rate of pumping remains unchanged strain analyses indicate that this result is due to the changing shape in the pore structure of the pumped aquifer as an elongation occurs in the horizontal direction to more than accommodateasmallcompressionalstrainintheverticaldirection uniaxialspecificstoragewasestimatedfromtime subsidence

spatiotemporal characterization of land subsidence and uplift in phoenix using insar time series and wavelet transforms the effects of land subsidence pose a significant hazard to the environment and infrastructure in the arid alluvial basins of phoenix arizona improving our understanding of the source and mechanisms of subsidence is important for planning and risk management here we employ multitemporal interferometric analysis of large synthetic aperture radar data sets acquired by ers and envisat satellites to investigate ground deformation the ers data sets from 1992 to 1996 and envisat 2003 2010 are used to generate line of sight los time series and velocities in both the ascending and descending tracks the general deformation pattern is consistent among data sets and is characterized by three zones of subsidence and a broad zone of uplift the multitrack envisat los time series of surface deformation are inverted to obtain spatiotemporal maps of the vertical and horizontal deformation fields we use observation wells to provide an in situ independent data set of hydraulic head levels then we analyze vertical interferometric synthetic aperture radar and hydraulic head level time series using continuous wavelet transform to separate periodic signal components and the long term trend the isolated signal components are used to estimate the elastic storage coefficient the inelastic skeletal storage coefficient and compaction time constants together these parameters describe the storage response of an aquifer system to changes in hydraulic head and surface elevation understanding aquifer parameters is useful for the ongoing management of groundwater resources

ground subsidence in semarang indonesia investigated by alos palsar satellite sar interferometry abstract the focus of this study is investigation of land subsidence in semarang city indonesia with the use of interferometry synthetic aperture radar insar of alos palsar satellite we processed 22 ascending sar images during january 2007 to january 2009 plus two descending sar images acquired on 6 june 2006 and 17 june 2007 the time series analysis of interferometry was performed by using 12 pairs of interferogram relative to 21 january 2007 and 8 pairs of interferogram relative 24 january 2008 the topographic phase contribution was removed using the 3 arcsec 90 m shuttle radar topography mission srtm digital elevation model dem we performed precision baseline estimation to vanish the fringes from baseline effect between master and slave data in order to investigate the contribution of horizontal movement in our analysis we constructed two interferograms of ascending orbit and descending orbit the time series results exhibited that the area is subsiding continuously without a significant seasonal effect during january 2007 to january 2009 the land subsidence observed from insar data is approximately up to 8 cm year three cross sections on image displacement show the extreme land subsidence occurred especially along the coastal area and lowland area where this area is considered as industrial with high density settlements consuming a lot of groundwater and land is changed from agriculture and cultivation purposes to industrial estates and house our result also shows a consistency with historical pattern of subsidence measured by leveling data the results highlight the potential use of insar measurements to provide better constraints for land subsidence in semarang city indonesia

field experiments and numerical simulations of confined aquifer response to multi cycle recharge recovery process through a well summary shanghai is one of the cities suffering from land subsidence in china land subsidence has caused serious financial losses thus artificial recharge measures have been adopted to compensate the drawdown in shallow confined aquifers and thereby control land subsidence in this study a multi cycle recharge recovery field experiment was performed to investigate the response of a shallow confined aquifer to artificial recharge through a well in the experiment a series of recharge recovery cycles with different recharge volumes and durations with and without artificial pressure were performed the water levels monitored in the recharge and observation wells indicated the response of the aquifer to the multi cycle recharge recovery process meanwhile a finite difference method fdm numerical model was established and its parameters were obtained via a reversed numerical analysis on the experimental data the responses of the shallow confined aquifer to the multi cycle recharge recovery process were simulated in detail using the model the calculation results showed that the water level dropped significantly when the recharge ended moreover the efficiency of a multi cycle recharge was found to be higher than that of a concentrated one under the same recharge volume and time the relationship between recharge frequency and efficiency expressed as h 0 29498 f 0 40163 and r 2 0 97264 respectively was obtained through the fdm numerical simulation in the recharge intervals the optimal recharge efficiency was achieved when the water level rose to 40 of the peak

quantifying ground deformation in the los angeles and santa ana coastal basins due to groundwater withdrawal we investigate complex surface deformation within the los angeles and santa ana coastal basins due to groundwater withdrawal and subsequent aquifer compaction expansion we analyze an 18 year interferometric synthetic aperture radar insar time series of 881 interferograms in conjunction with global positioning system gps data within the groundwater basins the large data set required the development of a distributed time series analysis framework able to automatically decompose both the insar and gps time series into short term and long term signals we find that short term seasonal oscillations of ground elevations due to annual groundwater withdrawal and recharge are unsteady due to changes in seasonal withdrawal by major water districts the spatial pattern of seasonal ground deformation near the center of the basin corresponds to a diffusion process with peak deformation occurring at locations with highest groundwater production long term signals occur over broader areas and are ultimately caused by long term changes in groundwater production comparison of the geodetic data with hydraulic head data from major water districts suggests that different regions of the groundwater system are responsible for different temporal components in the observed ground deformation short term seasonal ground deformation is caused by compaction of shallower aquifers used for the majority of groundwater production whereas long term ground deformation is correlated with delayed compaction of deeper aquifers and potential compressible clay layers these results demonstrate the potential for geodetic analysis to be an important tool for groundwater management to maintain sustainable pumping practices

simulation of groundwater flow and environmental effects resulting from pumping in coastal lowland plains increased water demand on a limited water resource has resulted in declining groundwater levels land subsidence and saltwater encroachment in southwestern kyushu japan a sinking of the land surface due to over pumping of groundwater has long been recognized as a problem in the shiroishi lowland plain in this paper an integrated model was established for the shiroishi site using the modular finite difference groundwater flow model modflow by mcdonald and harbaugh 1988 and the modular three dimensional finite difference groundwater solute transport model mt3d by zheng 1990 to simulate groundwater flow hydraulics land subsidence and solute transport in the alluvial lowland plain firstly problems associated with these groundwater resources were discussed and then the established model was applied the simulated results show that subsidence rapidly occurs throughout the area with the central prone in the center part of the plain moreover seawater intrusion would be expected along the coast if the current rates of groundwater exploitation continue sensitivity analysis indicates that certain hydrogeologic parameters such as an inelastic storage coefficient of soil layers significantly contribute effects to both the rate and magnitude of consolidation monitoring the present salinization process is useful in determining possible threats to fresh groundwater supplies in the near future in addition the integrated numerical model is capable of simulating the regional trend of potentiometric levels land subsidence and salt concentration the study also suggests that during years of reduced surface water availability reduction of demand increase in irrigation efficiency and the utilization of water exported from nearby basins are thought to be necessary for future development of the region to alleviate the effects due to pumping

mining geohazards susceptibility and risk mapping the case of the amyntaio open pit coal mine west macedonia greece during the last decades numerous methodologies for the construction of both susceptibility and risk maps have been developed in order to identify and mitigate geohazards such as landslides and secondarily land subsidence phenomena caused by the collapse of natural or man made underground cavities according to literature review the conducted research concerning the assessment of land subsidence risk due to the overexploitation of the aquifer is still at an early stage this study focuses n the land subsidence phenomenon due to the overexploitation of the aquifer occurring in the amyntaio basin in west macedonia hosting the active amyntaio open pit coal mine this phenomenon has caused significant damage to settlements farmlands and infrastructure in order to construct susceptibility and risk maps knowledge of the geological geotechnical hydrogeological and tectonic settings of the study area is required the proposed methodology for the production of a susceptibility and a risk map of land subsidence was based on the semi quantitative method weighted linear combination wlc the results were evaluated with an extensive field survey action recording besides the above mentioned settings the spatial distribution of surface ruptures the excellent agreement between the produced maps and the findings of the field survey proved the added value of the maps assigning them as crucial tools for the management of land subsidence phenomena

geomechanics of subsurface water withdrawal and injection land subsidence and uplift ground ruptures and induced seismicity are the principal geomechanic effects of groundwater withdrawal and injection the major environmental consequence of groundwater pumping is anthropogenic land subsidence the first observation concerning land settlement linked to subsurface processes was made in 1926 by the american geologists pratt and johnson who wrote that the cause of subsidence is to be found in the extensive extraction of fluid from beneath the affected area since then impressive progress has been made in terms of a recognizing the basic hydrologic and geomechanic principles underlying the occurrence b measuring aquifer compaction and ground displacements both vertical and horizontal c modeling and predicting the past and future event and d mitigating environmental impact through aquifer recharge and or surface water injection the first milestone in the theory of pumped aquifer consolidation was reached in 1923 by terzaghi who introduced the principle of effective intergranular stress in the early 1970s the emerging computer technology facilitated development of the first mathematical model of the subsidence of venice made by gambolati and freeze since then the comprehension measuring and simulation of the occurrence have improved dramatically more challenging today are the issues of ground ruptures and induced triggered seismicity which call for a shift from the classical continuum approach to discontinuous mechanics although well known for decades anthropogenic land subsidence is still threatening large urban centers and deltaic areas worldwide such as bangkok jakarta and mexico city at rates in the order of 10 cm yr

time dependent land uplift and subsidence in the santa clara valley california from a large interferometric synthetic aperture radar data set 1 we invert 115 differential interferograms derived from 47 synthetic aperture radar sar scenes for a time dependent deformation signal in the santa clara valley california the time dependent deformation is calculated by performing a linear inversion that solves for the incremental range change between sar scene acquisitions a nonlinear range change signal is extracted from the ers insar data without imposing a model of the expected deformation in the santa clara valley cumulative land uplift is observed during the period from 1992 to 2000 with a maximum uplift of 41 18 mm centered north of sunnyvale uplift is also observed east of san jose seasonal uplift and subsidence dominate west of the silver creek fault near san jose with a maximum peak to trough amplitude of 35 mm the pattern of seasonal versus long term uplift provides constraints on the spatial and temporal characteristics of water bearing units within the aquifer the silver creek fault partitions the uplift behavior of the basin suggesting that it acts as a hydrologic barrier to groundwater flow while no tectonic creep is observed along the fault the development of a low permeability barrier that bisects the alluvium suggests that the fault has been active since the deposition of quaternary units

the effects of pulsed pumping on land subsidence in the santa clara valley california abstract land subsidence caused by pulsed and constant pumping schemes was calculated and the results were compared to determine the possible advantages of pulsed pumping in reducing land subsidence pulsed pumping refers to pumping strategies involving alternation between periods of pumping and recovery in a well subsidence was calculated using a numerical model based on the santa clara valley ca the model accounts for delay in the release of water from storage in compressible interbeds as well as flow within aquifers for these tests the ratio of pumping period length to recovery period length was either 1 1 or 1 3 pulsing interval length length of one pumping period plus one recovery period ranged from 4 to 90 days pumping rates were adjusted so that pulsed pumping and constant pumping removed the same volume of water over the period under consideration pulsed pumping has the potential to concentrate subsidence around the pumping well for all simulations pulsed pumping caused greater subsidence near the test well than constant pumping under some conditions a transition point was reached beyond which pulsed pumping caused less subsidence than steady pumping the distance from the test well to the transition point decreases for a decreasing aquifer transmissivity b decreasing ratio of pumping period to recovery period and c increasing pulsing interval length the concentration of subsidence was reduced considerably when delay in release of water from storage in compressible aquitards was neglected indicating the importance of including delay effects in subsidence studies all pulsed pumping strategies caused a greater total volume of subsidence than steady pumping

interseismic coupling and refined earthquake potential on the hayward calaveras fault zone interseismic strain accumulation and fault creep is usually estimated from gps and alignment arrays data which provide precise but spatially sparse measurements here we use interferometric synthetic aperture radar to resolve the interseismic deformation associated with the hayward and calaveras faults hf and cf in the east san francisco bay area the large 1992 2011 sar data set permits evaluation of short and long wavelength deformation larger than 2 mm yr without alignment of the velocity field to a gps based model our time series approach in which the interferogram selection is based on the spatial coherence enables deformation mapping in vegetated areas and leads to refined estimates of along fault surface creep rates creep rates vary from 0 2 mm yr on the northern cf to 14 2 mm yr on the central cf south of the hf surface junction we estimate the long term slip rates by inverting the long wavelength deformation and the distribution of shallow slip due to creep by inverting the remaining velocity field this distribution of slip reveals the locations of locked and slowly creeping patches with potential for a m6 8 0 3 on the hf near san leandro a m6 6 0 2 on the northern cf near dublin a m6 5 0 1 on the hf south of fremont and a m6 2 0 2 on the central cf near morgan hill with cascading multisegment ruptures the hf rupturing from berkeley to the cf junction could produce a m6 9 0 1 the northern cf a m6 6 0 1 the central cf a m6 9 0 2 from the junction to gilroy and a joint rupture of the hf and central cf could produce a m7 1 0 1

geodetic tools for hydrogeological surveys 3d displacements above a fractured aquifer from gps time series deep porous reservoirs are subject to charge and discharge of fluids oil gas or water either naturally or induced by human exploitation this leads to a variation in pressure inside the reservoir and consequently to a deformation of the overlying material the knowledge of the ground surface displacements allows inferring the fluid migrations and the hydromechanical properties in the porous reservoir different kinds of geodetic tools are able to measure this ground deformation gps radar interferometry insar tiltmeters or leveling each of them has its own spatial and time characteristics and accuracies that conduct to different kind of applications after a review of the geodetic studies applied to hydrogeological processes we describe two examples of gps time series measurements above the granitic fractured aquifer of ploemeur located in french brittany these time series records the 3d displacements induced by the sum of different processes in this site the involved processes are mainly the ground deformation related to piezometric level variations in the aquifer that we are looking for and the ocean tide loading that can reach several centimeters in the study area we present the protocol of the gps data survey and the processing strategy applied to extract the effect of hydrogeological process with sufficient accuracy two different experiments were studied the long term deformation corresponding to seasonal hydrological cycle and the short term deformation associated to a pumping test for a same variation in piezometric levels the vertical ground displacements show larger amplitude for long term signal than for short one indicating a behavior depending on the duration of the hydrogeological load this difference of reactivity in time can be related to the heterogeneity of the studied aquifer finally this work shows that geodetic measurements provide important constraints for characterizing aquifer system response

correlation between groundwater level and altitude variations in land subsidence area of the choshuichi alluvial fan taiwan one of the prominent features observed in the groundwater overdraft area is the land subsidence that creates a permanent damage to the land surface severe land subsidence has occurred in the western taiwan due to excessive extraction of groundwater in the past decades the areas of land subsidence have been gradually expanded and caused many problems such as flooding and building damage this study examines the elevation changes on surface which is the vertical component from the global positioning system in the choshuichi alluvial fan of central taiwan and describes the land subsidence phenomena quantitatively the choshuichi alluvial fan has a high density array of wells monitoring the groundwater level variations of various aquifers automatically in an hourly basis through an assumed linear relationship the inferred results show that the global positioning system data are closely correlated to the groundwater level variations of deep aquifers the highest correlations between elevation changes and groundwater level variations have been found in the land subsidence area even if a drought period is present the responses on the surface vertical displacements from the groundwater level changes of deep aquifers can be quantitatively estimated furthermore the long term subsidence trends can be derived and be used as useful reference for land and water resources management

gps measurements of ground deformation induced by water level variations into a granitic aquifer french brittany we used two semi permanent gps receivers with differential configuration to measure the hydrological subsidence of an aquifer used for water supply located on a fractured granitic area the time series of the vertical deformation measurements of the ground surface show a variation of 2 cm between winter and summer we investigate the relationship between this vertical deformation and hydraulic head variations we show that this kind of gps survey allows characterizing part of the hydrological properties of such a heterogeneous aquifer this is thus a new approach of time continuous monitoring of the deformation related to hydrogeological processes

remote sensing of ground deformation for monitoring groundwater management practices application to the santa clara valley during the 2012 2015 california drought groundwater management typically relies on water level data and spatially limited deformation measurements while insar has been used to study hydrological deformation its limited temporal sampling can lead to biases in rapidly changing systems here we use 2011 2017 cosmo skymed data with revisit intervals as short as one day to study the response of the santa clara valley scv aquifer in california to the unprecedented 2012 2015 drought cross correlation and independent component analyses of deformation time series enable tracking water though the aquifer system the aquifer properties are derived prior to and during the drought to assess the success of water resource management practices subsidence due to groundwater withdrawal dominates during 2011 2017 limited to the confined aquifer and west of the silver creek fault similar to pre drought summer periods minimum water levels and elevations were reached in mid 2014 but thanks to intensive groundwater management efforts the basin started to rebound in summer 2015 during the deepening drought by 2017 water levels were back to their pre drought levels while elevations had not yet fully rebounded due to the delayed poroelastic response of aquitards and their large elastic compressibility as water levels did not reach a new low stand the drought led to only elastic and recoverable changes in the scv the scv lost 0 09 km3 during the drought while seasonal variations amount to 0 02 km3 analysis of surface loads due to water mass changes in the aquifer system suggests that groundwater drawdowns could influence the stress on nearby faults

interbed storage changes and compaction in models of regional groundwater flow water released from permanent compaction of compressible fine grained interbeds within confined aquifers may be a significant source of pumped water permanent or inelastic compaction of the interbeds occurs when head declines from pumping cause the effective stress or grain to grain load to exceed the elastic limits of the interbeds as a result the grains in the interbeds rearrange and excess water is expelled the amount of inelastic compaction generally is proportional to the increase in effective stress and the decrease in head a common approach for the simulation of elastic and inelastic compaction in groundwater flow models is to assume that head changes in the aquifer result in instantaneous storage changes in the compressible interbeds a term is added to the groundwater flow equation to account for the storage changes changes in specific storage may be computed explicitly from the results at the previous time step in the finite difference formulation of the groundwater flow equation a better approach is to implicitly apportion storage changes between elastic and inelastic components within a time step if storage changes cannot be considered to occur instantaneously with change in head in the aquifer another approach is taken equations for horizontal flow in the aquifer are coupled with equations for vertical flow in the compressible interbeds to simulate flow in half a representative doubly draining interbed storage changes and compaction are calculated for the representative half thickness and are extrapolated to the entire thickness of all interbeds within each cell this approach was applied to an existing model of groundwater flow in the central valley of california the simulation demonstrates that solving coupled systems of equations is feasible for a regional flow model

the effects of artificial recharge of groundwater on controlling land subsidence and its influence on groundwater quality and aquifer energy storage in shanghai china long term groundwater overpumping in shanghai has caused serious land subsidence to restore the declined piezometric groundwater levels and to decrease the land subsidence rate artificial recharge ar of groundwater into confined aquifers through injected wells has been proposed as an important measurement since the beginning of the 1960s in the case of shanghai recharge source is tap water whose chemical constituents and temperature are different from groundwater consequently the issues of groundwater quality change and thermal energy are worthy of discussion in this paper we discussed the influences of ar for controlling land subsidence on 1 groundwater level and land subsidence rate 2 groundwater quality 3 aquifer thermal energy storage the results based on the collected long term historical data in the study area show that ar not only is beneficial to groundwater level rising and land rebound but also provides cheap energy sources for industrial production the groundwater quality presented the trend of desalination and a general increase in sulfate iron and manganese contents organic and nitrogenous compounds after the tap water injection however the ar s influence on groundwater quality was limited with the radius 100 m for single well recharge and 1000 m for well groups recharge to control the development of the land subsidence within a safe limit in the study area the injected confined aquifers and the distribution of the ar wells need to be further adjusted due to the limitation of current ar

potential vorticity modeling of the itcz and the hadley circulation abstract a simple zonally symmetric balanced model of the hadley circulation is presented the model is based on potential vorticity arguments and consists of a predictive equation for the potential pseudodensity and an invertibility principle to diagnose the associated balanced wind and mass fields when the theory is formulated in the potential latitude coordinate the meridional advection is implicit in the coordinate transformation which makes the prediction equation for potential pseudodensity analytically solvable for convective heating patterns that simulate the itcz the model produces upper and lower tropospheric potential vorticity anomalies of opposite sign the associated winds are easterly at low levels and westerly aloft except between the equator and the itcz where there are low level westerlies and upper level easterlies since the potential vorticity anomalies develop within a background state that has potential vorticity increasing to the north reversed poleward gradients of potenti

groundwater resources management under environmental constraints in shiroishi of saga plain japan a sinking of the land surface due to the pumping of groundwater has long been recognized as an environmental issue in the shiroishi plain of saga japan land subsidence can have several negative economic and social implications such as changes in groundwater and surface water flow patterns restrictions on pumping in land subsidence prone areas localized flooding failure of well casings as well as shearing of structures to minimize such an environmental effect groundwater management should be considered in this area in this study a new integrated numerical model that integrates a three dimensional numerical groundwater flow model coupled with a one dimensional soil consolidation model and a groundwater optimization model was developed to simulate groundwater movement to predict ground settlement and to search for optimal safe yield of groundwater without violating physical environmental and socio economic constraints it is found that groundwater levels in the aquifers greatly vary from season to season in response to the varying climatic and pumping conditions consequently land subsidence has occurred rapidly throughout the area with the shiroishi plain being the most prone the predicted optimal safe yield of the pumping amount is about 5 million m3 the study also suggests that pumping with this optimal amount will minimize the rate of land subsidence over the entire area

fault controlled deformation and stress from pumping induced groundwater flow summary four two dimensional numerical model scenarios are developed to gain a better understanding of how earth fissures form under pumping induced stress the simulated aquifer aquitard system contains a low compressibility sub vertical 100 m wide fault zone that transects the hydrostratigraphic system that includes a 100 m thick vadose zone two scenarios represent constant and cyclical pumping over a 5 year period and two scenarios are used to evaluate the difference between using purely elastic aquitards versus elasto plastic aquitards the model provides for the analysis of the spatial distribution of deformation and normal and shear stress that potentially lead to the formation of earth fissures results indicate that this fault zone largely controls the deformation and stress regime of the system during pumping patterns of deformation and stress are similar for all scenarios with only the magnitudes being affected simulation results show that pumping induces a counterclockwise rotation of the fault plane on the footwall the distribution of deformation through the fault is damped and the deformation patterns are more subdued on the hanging wall but all deformation is directed toward the pumping well these deformation patterns result in two areas of stress accumulation that may lead to fissure formation a near the land surface in the fault zone and b near the saturated unsaturated interface on the hanging wall adjacent to the fault zone these results reveal the importance of both the fault and vadose zones in fissure genesis

land subsidence due to groundwater withdrawal in the northern beijing plain china abstract beijing is an international metropolis where over exploration of water resource makes land subsidence becoming more and more serious the related problems cannot be avoided in the coming years because of the giant increase of population the aims of this study are to quantify land subsidence over the period 2003 to 2010 grasp the evolution of the process and investigate the relation with the triggering factors in the northern area of the beijing plain various data including deep compaction from vertical multiple borehole extensometers land subsidence from persistent scatterer interferometry and leveling surveys groundwater levels hydrogeological setting from wellbores and landsat tm image were collected and effectively used to detect the spatial and temporal features of land subsidence and its possible relation with groundwater level changes compressible layer thickness and urban development results show that land subsidence is unevenly distributed and continuously increased from 2003 to 2010 the average loss of elevation over the monitoring period amounted to 92 5 mm with rates up to 52 mm y the distribution of the subsidence bowl is only partially consistent with that of the groundwater depression cone because of the variable thickness of the most compressible fine deposits in fact extensometers reveal that silty clay layers account for the larger contribution to land subsidence with the 15 m thick silty clay layer between 102 and 117 m depth accounting for about 25 of the total subsidence finally no clear correlation has been observed between the subsidence rates and the increase of the load on the land surface connected to the impressive urban development this study represents a first step toward the development of a physically based model of the subsidence occurrence to be used for planning remediation strategies in the northern beijing plain

transient deformation induced by groundwater change in taipei metropolitan area revealed by high resolution x band sar interferometry abstract we present precise deformation velocity maps for the two year period from september 2011 to july 2013 of the northern taiwan area taipei by using persistent scatterer interferometry psi technique for processing 18 high resolution x band synthetic aperture radar sar images archived from cosmo skymed csk constellation according to the result the highest subsidence rates are found in luzou and wuku area in which the rate is about 15 mm yr and 10 mm yr respectively in the whole dataset however dramatic change from serve subsidence to uplift in surface deformation was revealed in the taipei basin in two different time spans 2011 09 2012 09 and 2012 09 2013 07 this result shows good agreement with robust continuous gps measurement and precise leveling survey data across the central taipei basin moreover it also represents high correlation with groundwater table from 8 well data in the taipei basin the storativity is roughly constant across most of the aquifer with values between 0 5 10 4 and 1 6 10 3 in jingmei formation and 0 8 10 4 and 1 4 10 3 in wuku formation this high correlation indicated that one meter groundwater level change could induce about 9 and 16 mm surface deformation change in luzou and wuku area respectively which is about eight times faster the long term tectonic deformation rate in this area thus to access the activity of the shanchiao fault it is important to discriminate tectonic movement from anthropogenic or seasonal effect in the taipei basin to better understand the geohazards and mitigation in the taipei metropolitan area