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predict possible runoff conditions, which could also cause flooding events.
At the beginning of dry season, soil water content can be high as a result
of rainy season. However, the soil is commonly depleted of soil water at the
end of dry season.
4. Conclusions
The following conclusions can be drawn.
(1) Evaporation, overland flow and recharges to groundwater were
about 37.3%, 8.9%, and 53.8% of annual rainfall in the study area,
respectively.
(2) Since the cracks and high permeability of red soil in the study area, no
overland flow happened with daily rainfall less than 60 mm/day.
(3) There is a time lag between beginning of rainy season and rise of the
water table. The delay for ascending period for the water table was
largely dependent up on the accumulated rainfall in the year. However,
the descending period of the water table started at the end of rainy
season.
(4) The soil water content in the topsoil changed greatly because of strong
evaporation in the shiny day. The dry layer and cracks forming in the
surface help to prevent soil water loss from evaporation in the soil layer
30 cm below the surface. Also, cracks and surface sealing at the top soil
during the rainfall event should be the key for understanding overland
flow occurring in the study area.
References
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