Hydrologic behaviour of residual soil slopes in Singapore
Rezaur, R. B.
Leong, Eng Choon
Lee, T. T.
Date of Issue2003
School of Civil and Environmental Engineering
Monitoring hydrologic responses of slopes is critical for advancing hillslope hydrologic studies. Storm- and time-based continuous hydrologic responses from three instrumented hillslopes in Singapore were monitored for a period of 420 days to observe the impact of rainfall on the pore-water pressure changes and runoff generation. Analyses of the hydrologic data indicate that only about 37% of the annual rainfall events are capable of producing runoff, and a threshold rainfall of about 10 mm is required to produce runoff. The seasonal distribution of pore-water pressures showed that the slopes experience high matric suctions during dry periods that are comparable to matric suctions observed in other tropical climates, and positive pore-water pressures during wet periods, that are higher than in other geographic locations. A high correlation between the increase in pore-water pressure and the daily rainfall may provide a convenient estimate of the increase in pore-water pressure due to the daily rainfall. The variability of hillslope hydrologic responses from storm to storm is distinctive when compared with previous results at other geographic locations.
Journal of hydrologic engineering
© 2003 ASCE