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| Titel |
Integrating a Linear Signal Model with Groundwater and Rainfall time-series on the Characteristic Identification of Groundwater Systems |
| VerfasserIn |
Yu-Wen Chen, Yetmen Wang, Liang-Cheng Chang |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250141761
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| Publikation (Nr.) |
 EGU/EGU2017-5302.pdf |
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| Zusammenfassung |
| Groundwater resources play a vital role on regional supply. To avoid irreversible
environmental impact such as land subsidence, the characteristic identification of
groundwater system is crucial before sustainable management of groundwater resource. This
study proposes a signal process approach to identify the character of groundwater systems
based on long-time hydrologic observations include groundwater level and rainfall. The study
process contains two steps. First, a linear signal model (LSM) is constructed and calibrated to
simulate the variation of underground hydrology based on the time series of groundwater
levels and rainfall. The mass balance equation of the proposed LSM contains three major
terms contain net rate of horizontal exchange, rate of rainfall recharge and rate of pumpage
and four parameters are required to calibrate. Because reliable records of pumpage is rare, the
time-variant groundwater amplitudes of daily frequency (P ) calculated by STFT are assumed
as linear indicators of puamage instead of pumpage records. Time series obtained from 39
observation wells and 50 rainfall stations in and around the study area, Pintung Plain, are
paired for model construction. Second, the well-calibrated parameters of the linear
signal model can be used to interpret the characteristic of groundwater system. For
example, the rainfall recharge coefficient (γ) means the transform ratio between rainfall
intention and groundwater level raise. The area around the observation well with higher
γ means that the saturated zone here is easily affected by rainfall events and the
material of unsaturated zone might be gravel or coarse sand with high infiltration ratio.
Considering the spatial distribution of γ, the values of γ decrease from the upstream to the
downstream of major rivers and also are correlated to the spatial distribution of
grain size of surface soil. Via the time-series of groundwater levels and rainfall, the
well-calibrated parameters of LSM have ability to identify the characteristic of aquifer. |
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