DETERMINATION OF EROSION RISK LEVEL AT THE DOWNSTREAM OF KELANTAN RIVER - INTERNATIONAL CONFERENCE ON BIOENGINEERING AND TECHNOLOGY (IConBET2021)
Riverbank erosion is an undesired phenomenon and was always given special attention by engineers and authorities in the past. Human activities are believed to accelerate the process of erosion in either terrestrial areas or in the river system. The hydraulic force will prompt toe erosion at the water edge, while the percentage of soil composition always induces potential mass wasting at the upper riverbank section. The second category of erosion was given special attention in this study. The aftermath of the 2014 catastrophe flood in Kelantan initiated gradual erosion along the Kelantan River network. It is believed that the vegetative cover at the riverbank section was washed away by the flooding event. The exposure of bare soil is susceptible to erosion should the rainfall erosivity exceeds the capacity of soil to withstand the interlocking texture. Therefore, this study was performed to assess the potential risk of riverbank erosion in the area where no vegetative cover was detected. The study area was focused on the downstream part of the Sg Kelantan River basin due to the dense population and active socio-economic activities. The hand Auger was deployed to extract the soil composition along the riverbank. The device was hammered at an approximate 50 mm- 1 meter beneath the ground surface to sample the undisturbed soil. The soils were brought to the lab for sieving and hydrometer analysis. The main purpose of laboratory work is to obtain a complete grain size distribution. The final grain size distribution was mapped against the RON index to obtain the potential risk of either “low”, “moderate”, “high”, “very high”, or “critical” erosion. The output of this study revealed that point number 3 (N 6°11’50”, E 102°14’5”) and point number 4 (N 6°12’22”, E 102°14’5”) are susceptible to critical erosion risk levels based on soil composition. These two points were located downstream from Sungai Kelantan and near the residential area. It is expected that high rainfall erosivity will induce severe riverbank erosion at these two points.
Authors
Abstract
Riverbank erosion is an undesired phenomenon and was always given special attention by engineers and authorities in the past. Human activities are believed to accelerate the process of erosion in either terrestrial areas or in the river system. The hydraulic force will prompt toe erosion at the water edge, while the percentage of soil composition always induces potential mass wasting at the upper riverbank section. The second category of erosion was given special attention in this study. The aftermath of the 2014 catastrophe flood in Kelantan initiated gradual erosion along the Kelantan River network. It is believed that the vegetative cover at the riverbank section was washed away by the flooding event. The exposure of bare soil is susceptible to erosion should the rainfall erosivity exceeds the capacity of soil to withstand the interlocking texture. Therefore, this study was performed to assess the potential risk of riverbank erosion in the area where no vegetative cover was detected. The study area was focused on the downstream part of the Sg Kelantan River basin due to the dense population and active socio-economic activities. The hand Auger was deployed to extract the soil composition along the riverbank. The device was hammered at an approximate 50 mm- 1 meter beneath the ground surface to sample the undisturbed soil. The soils were brought to the lab for sieving and hydrometer analysis. The main purpose of laboratory work is to obtain a complete grain size distribution. The final grain size distribution was mapped against the RON index to obtain the potential risk of either “low”, “moderate”, “high”, “very high”, or “critical” erosion. The output of this study revealed that point number 3 (N 6°11’50”, E 102°14’5”) and point number 4 (N 6°12’22”, E 102°14’5”) are susceptible to critical erosion risk levels based on soil composition. These two points were located downstream from Sungai Kelantan and near the residential area. It is expected that high rainfall erosivity will induce severe riverbank erosion at these two points.
Citation
ABDUL HAFIDZ YUSOFF, SITI NURFAZREEN ABDUL RAHMAN, MOHD SOFIYAN SULAIMAN, IR. MARINI MOHAMAD IDERIS , GOH YEE CAI. 2022. DETERMINATION OF EROSION RISK LEVEL AT THE DOWNSTREAM OF KELANTAN RIVER - INTERNATIONAL CONFERENCE ON BIOENGINEERING AND TECHNOLOGY (IConBET2021) . Digital NAHRIM Publication Repository.