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| Titel |
Land subsidence monitoring in central Taiwan by using PS-InSAR technique |
| VerfasserIn |
J.-C. Hu, H. Tung, M.-H. Huang |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250024808
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| Zusammenfassung |
| Ground subsidence induced by heavy withdrawal of underground water has resulted in
environmental hazard and potential risk in Taiwan, particularly in the Choushui River alluvial
fan where the Yunlin section of the Taiwan High Speed Rail had been constructed. The
Yunlin County located in the southwestern coastal region of Taiwan is one of the most
counties with serious land subsidence because of the agricultural needs. Yunlin County is
one of the important agricultural production regions located in the southwestern
coastal region of Taiwan where the irrigated area is up to 123,000 hectares and
agricultural water consumption reaches approximate 90 percents of all available water
resources in the Choshui River Basin. Moreover, since there is no sufficient surface
water supplied, groundwater becomes a vital resource for every water consumption
targets. Seasonal effects of land subsidence occurring in the study area had been
estimated using a regression analysis of a series of weekly GPS height solutions. These
results demonstrated the average rate of ground subsidence in this area over the
period of 1995-2001 was 3 cm/yr. Based on data collected at the piezometer, the
variation of land subsidence rate appears to be associated with an unstable underground
water level, which drop gradually during winter and either remains constant or
rises during summer time. Consequently, land subsidence rates vary considerably
from 1.5 cm/yr for the summer time to 9.0 cm/yr for the winter time. In addition,
anthropogenic ground subsidence due to massive pumping of groundwater is one
of problems in Taiwan. In this study, we represented a both stacking D-InSAR
and PS-InSAR results deduced from 1996-1999 time spans for monitoring of land
subsidence in this area. Both D-InSAR and PS-InSAR results show the Baojhou,
Tuku Township and northern Mailiao reveal a maximum subsidence rate of about 6
cm/yr along LOS and the Taishi Township located on the coastal area reveals a
subsidence rate of 1.6 cm/yr, which is quite coincident with precise leveling result.
These two results have proven that the effective reduction of labor and cost could be
achieved by using this technique on monitoring land subsidence in Yunlin County. |
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