The determination of infiltration rates on soils of various landuses using drip-type rainfall simulator
1997
Othman Asmaon | Hamirdin Ithnin
The rationale of this study is that land clearing causes changes to soil physical properties such that an important measure, the infiltration rate, is greatly affected. This in turn has series consequences on the processes related to soil. The objective of this paper is to illustrate the use of a methodology to determine the rates of infiltration. Due to the difficulties in measuring infiltration rates based on actual rainfall incidence, simulated rainfall was opted for in the study. The methodology was based on the drip-type infiltrometer, (referred thereafter as rainfall simulator). It consisted of a water tank, a flow meter, a raindrop producer, a bordered infiltration square and a run off collector. Water from the tank was made to flow through the flow meter and the raindrop producer. The raindrop producer has 49x37 cm coverage. Before actual simulation, relationship between rainfall intensity and flow rate was first calibrated. During simulation, runoff was collected at 5, 10 and 30 minutes intervals. The infiltration rate was determined by subtracting rate of runoff from rate of rainfall. The results of the simulation were as follows: under rainforest (control), the infiltration rate (cm/hr) was 21, oil palm (7 years) - 8.3, oil palm (20 years) - 20.5, rubber (7 years) 8.1, rubber (20 years) - 21, bare soil (one-year) - 6.6 and bare soil (5 years) - 4.7. The drip-type rainfall simulator method is thus sufficiently adequate for determining the infiltration rates of various soils.
显示更多 [+] 显示较少 [-]