Geoscience Reference
In-Depth Information
hillslope and the riparian zone. It was progressively increased with depth.
This evidence showed that source of Ca
2+
in the stream channel has been
dominated by that discharging from the NSR. The processes suggest that
the dynamic of Ca
2+
has been much determined by the flow process rather
than that defined by the dilution process.
5. Conclusions
The hydrometric, Ca
2+
concentration and mineralogical data of the catch-
ment studied suggest that (a) Ca
2+
deterioration is prominently occurred
from which the subsurface runoff governing transport of Ca
2+
is domi-
nance, the process by which the Ca
2+
is leached out, (b) shallow ripar-
ian groundwater (near surface riparian) is the most dominant source area,
which releases much concentration of Ca
2+
,and(c)Ca
2+
deterioration will
be much obvious when the input through weathering is lower to that of the
output through the transport process.
This study provides insight into the role of the major subsurface flow
on the potential leaching of conservative solutes in a headwater catchment.
The nature of weathering and solutes dilution determines their mixture gen-
erating the stream chemistry. It is urgently needed to expand the study into
the topic of biogeochemical behavior rather than that of hydrochemistry.
Acknowledgments
The study has been funded by the Ministry of Education, Science, Sport
and Culture of Japan (MONBUSHO). Thanks are extended to Prof. Dr.
Norio Tase and Dr Michiaki Sugita for valuable suggestions and Dr. Tamao
Hatta for his assistance on XRD analysis.
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