ANALYSIS OF VERTICAL MOVEMENTS DETECTED BY RADAR INTERFEROMETRY IN URBAN AREAS

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1 10TH CZECH-POLISH WORKSHOP ON RECENT GEODYNAMICS OF THE SUDETEN AND ADJACENT AREAS Szklarska Poręba, Poland, November 5 7, 2009 ANALYSIS OF VERTICAL MOVEMENTS DETECTED BY RADAR INTERFEROMETRY IN URBAN AREAS Kadlečík Pavel, Schenk Vladimír, Seidlová Zuzana, Schenková Zdeňka Centre for Earth Dynamics Research Institute of Rock Structure and Mechanics, Academy of Sciences of the Czech Republic, Prague, v.v.i.; kadlecik@irsm.cas.cz

2 Application InSAR in urban areas PSI (Persistent Scatterer interferometry) DInSAR (Differential Interferometry) InSAR data acquired in Terrafirma ESA project processed by GAMMA Remote Sensing, Switzerland 2 areas: Prague, The Ostrava region PSI - IPTA (Interferometric Point Target Analysis) (Werner et al. 2003) primary analysis (derived from ERS-1/2) additional analysis (especially two-year - ERS-1/2, ENVISAT) RESULTS average deformation rate (change in vertical position) for PS time series for PS Differential interferograms (only for the Ostrava region) 1-day, 35- to 71-day processed from ERS-1/2 scenes during RESULTS sum of vertical movement for processed period (generally 35 or 70 days)

3 PRAGUE AREA PSI (Persistent Scatterer interferometry) average deformation rates and are included because of allowing different def. rates Study areas 3 examples 1. STODŮLKY CANALIZATION construction of canalization feeder ( ) jump nature of subsidence complicated geological situation 2. BRANÍK RAILWAY TRACK slow subsidence for whole period cause of movement: instability of sediments building the railway embankment local distinction of movement

4 OSTRAVA REGION processed by GAMMA Remote Sensing PSI - IPTA (Interferometric Point Target Analysis) average deformation rates average deformation rates for shorter periods , , , (all ERS-1/2), (ENVISAT) differential interferograms 1-day, 35-day, 70-day from period undermined region subsidence up to tens of cm/year 3. MICHAL MINE former mine Petr Cingr located in settled parts of the Ostrava city closed in April 1994 analysis of subsidence during coal-mining and after Study areas 3 examples

5 1. STODŮLKY CANALIZATION construction of canalization (sewer) feeder kanalizační č přivqděč builded ; in depth m under surface subsidence along the line of feeder average vertical movements ( ) up to 4,5 mm per year jump nature of movement 5-20 mm during 1-7 months analysed data - PSI complicated geological situation (silurianordovician complex) housing estate Stodůlky builded in the 1980s line of drainage

6 1. STODŮLKY CANALIZATION

7 Cross-section profiles 1. STODŮLKY CANALIZATION average deformation rates (mm/year) 4 2 A A C B 4 2 B C line of drainage

8 GEOLOGY - ordovician-silurian complex - zvrásnění komplex sedimentárních hornin středního ř a svrchního ordoviku a spodního siluru s vulkanickými průniky diabazových těles a žil - jílovité a prachovité břidlice, písčité břidlice až pískovce, produkty diabazového vulkanismu 1. STODŮLKY CANALIZATION

9 1. STODŮLKY CANALIZATION Time series analysis jump 5-20 mm during 1-7 months along the line of canalization

10 track runs on railway embankment (2-3 m high) h) m far from the Vltava river embankment was transfered towards to river (finished in 1992) part of antiflood protection of Prague analysed data - PSI BRANÍK RAILWAY TRACK

11 subsidence of track varying in 1,5 65 6,5 mm per year ( ) subsidence is evident for whole period BRANÍK RAILWAY TRACK Time series character of movement

12 Time series analysis detected 2 events November January 1993 August November 2004 flood in summer 2002 water rised 1 m under top of embankment not distinct display on time series of PS 2. BRANÍK RAILWAY TRACK flood

13 2. BRANÍK RAILWAY TRACK 60,000 40,000 20,000 0, ,000-40,000-60,000 60,000 40,000 20,000 0, ,000-40,000-60,000 60,000 40,000 20,000 possible explanation - non-uniform sinking of the embankment-massmass not long from its building 0, ,000-40,000-60,000

14 3. MICHAL MINE former Petr Cingr mine czech part of Upper Silesian Basin coal mining ended in 1994 located in settled part of Ostrava City analysed data - PSI , DInSAR (about 20 differential interferograms from these period)

15 3. MICHAL MINE MAXIMUM DEFORMATION RATE (mm/year) CENTER OTHER mining ended

16 3. MICHAL MINE

17 absence of PS 3. MICHAL MINE

18 3. MICHAL MINE Total rate of subsidence for period (mm) mining ended

19 Application of InSAR in urban areas Prague very stable area (92% of PS movement up to +-2 mm/year in period ) PSI data can detect long-term movements in mm range Short-term movements in mm and cm range The Ostrava region primary cause of movement coal mining subsidence bid up to tens of centimeter t per year PSI data not detected maximum rate of movement (center of sudsiding depression) can detect subsidence in period after the end of the coal mining DInSAR data can detect movements in tens of cm per year maximum detectable rate of movement (wavelength of ERS-1/2, ENVISAT 56 mm) InSAR data can detect origin and spatio-temporaltemporal progress of subsiding depression For analysing InSAR dat vertical movement (from changes in the LOS direction) > possible horizontal movement reference point (relative values) PSI time series the value of vertical position not for every repeat cycle (e.g. 35 days)

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