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| Titel |
{Contribution of mountainous flow to the lateral recharge of downstream sedimentary aquifer} |
| VerfasserIn |
Y. H. Kao, C. W. Liu, T. Y. Lin, K. H. Lin |
| 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 |
250021363
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| Zusammenfassung |
| Groundwater is one of the most important and indispensable water resources. Groundwater
consists of 40% of the total water resources utilization in Taiwan. Among 10 groundwater
regions, Choushui river alluvial fan is the largest region which supplies 1.2-1.5 billion tons of
water annually. The mountainous catchment located in the upstream of Choushui river
alluvial fan, and Wuchi river basin, plays an important role in conveying surface and
subsurface runoff to the downstream sedimentary aquifers. The purpose of the study is to
estimate the annual groundwater lateral recharge from upstream mountainous area using
base-flow and rainfall infiltration methods. Meanwhile, Geographic Information Systems
(GIS) is applied to facilitate the estimation. The monthly base-flow data of the representative
stations of each basin were collected and complied. The amount of groundwater recharge
were obtained by multiplying the estimated annual base-flow (m/yr) with the corresponding
catchment area (m2). The total lateral recharge estimated from upper mountainous areas was
10.85×109m3/yr where Wuchi river and Choushui river basins comprised 0.273
(25.2%) and 0.812 (74.8%) billion ton/year, respectively. These results are similar to
those estimated by O18 isotopic analysis where 22% and 78% were from the Wuchi
river and Choushui river basins, respectively. Moreover, the estimate amount using
C14 of the lateral flow in the upstream Choushui river alluvial fan was 0.83 billion
ton/year, which is close to our estimation. Groundwater recharged from rainfall
infiltration was estimated based on precipitation, evaporation, land use, soil types.
The total groundwater recharge obtained by the rainfall infiltration method from
upper mountainous area is 1.064 billion ton/year, which is close to 1.085 billion
ton/year by the base-flow method. These results provide reliable data of the input
of boundary conditions for the modeling of subsurface groundwater flow model. |
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