Hillslope hydrology in tropical rainforest steeplands in Brunei.

摘要: Many remaining areas of tropical rainforest in south-east Asia are located on landscapes dominated by deep valleys and very steep slopes. Now that logging activities extending into these steeplands, it is essential to understand how the natural system behaves if any kind realistic assessment effects such disturbance be made. This paper examines hydrological behaviour an undisturbed topography Temburong District Brunei, north-west Borneo. The physical properties regolith material generally typical residual soils. has a clay texture low dry bulk density beneath superficial litter/organic horizon. infiltration capacity surface soil was several hundred mm h−1. That exposed mineral subsoil order magnitude less, similar saturated hydraulic conductivity (Ksat) around 180 h−1 at depth 150 cm. There no indication Ksat reduced with except near bedrock interface. Soil tensions were measured using two-dimensional array tensiometers 30° slope. During season conditions, infiltrating rain-water contributes moisture, drying transpiration losses. wet perched water tables quickly develop during heavy rainfall, giving rise rapid production return flow ephemeral channels. No excess or saturation overland observed hillslopes away from channel margins. Subsurface storm combined produce stream hydrographs high peak discharges short lag times. Storm event runoff coefficients estimated as 40%. It concluded most distinctive feature hydrology this ‘steepland rainforest’ extremely ‘flashy’ nature catchment regime produced combination thin but permeable Copyright © 2000 John Wiley & Sons, Ltd.