Sediment size and deposition characteristics in Malaysian urban concrete drains – a case study of Kuching City

Abstract

This paper highlights the results of sediment size characteristics and deposition analysis on 24 sediment samples from urban concrete drains in Kuching City. Further sampling from surrounding urban towns outside Kuching City and Penang were done for comparison. Samples were collected randomly from three land-use types (residential, commercial and industrial). Sieve analysis results had shown that most of the total samples collected (51 out of 57) were predominantly sand, followed by gravel; while silt and clay were the minor components. Unimodal characteristics were observed in 46 samples while 11 samples showed bimodal characteristics. Of the total 46 unimodal samples, 39 showed non-uniform distribution with tendency to skew to the right. Due to this, the mode grain size with characteristic diameter d₄₅ is suggested as a much better representative size than the conventional median size d₅₀. Factors affecting sediment deposition characteristics in urban drains are also discussed.

Keywords::

• characteristic diameter
• deposition
• sediment
• urban areas
• urban drainage

Acknowledgements

The authors would like to thank the Civil Engineering Department, Universiti Malaysia Sarawak and River Engineering and Urban Drainage Research Centre (REDAC), Universiti Sains Malaysia for the use of the laboratory and equipments during the sample collection and field works. Also special thanks to Dr. Darrien Mah Yau Seng, Dr. Tay Kai Meng, Mr. Ron Aldrino, Mr. Ravikanth Chittripolu and the technicians who had helped during the field work. Special appreciation goes to Ms. Rayhana Pangilan for checking the paper for grammatical errors. The authors would also like to thank UNIVERSITI SAINS MALAYSIA for financial support under the RU-PRGS grant No. 1001/PREDAC/8044050.