SUSPENDED SEDIMENT CONCENTRATION AND TURBIDITY RELATIONSHIP IN TWO SMALL CATCHMENTS IN PERLIS, MALAYSIA

The estimation of suspended sediment transport in river is generally based on relationships between suspended sediment and discharge, but these correlations are often poor and are frequently difficult to measure especially during storm events. Extrapolation using discharge in regular sampling involved large errors. An alternative approach is event sampling using automatics sampler but it is expensive and large numbers of samples needed for analysis. In response to this problem, the relationship between suspended sediment and turbidity approach offers a relatively rapid and inexpensive method. A study were conducted from October 2001 to October 2002 involving a fortnightly water sampling and discharge measurement, and two intensive sampling programs (1-4 October 2001 and 11-12 October 2001) at two small catchments areas in northern Perlis. Results from this study show that strong relationships existed between suspended sediment concentrations and turbidity, and vise versa. A good positive relationship suggests that turbidity is possibly the best surrogate for suspended sediment concentrations in estimating the river suspended sediment transport.