ABSTRACT:

Estimating Sediment Discharge at a Sediment-Filled Dam in Malibu Creek using Digital Elevation Models (DEM)

Chong, Jeng Hann, California State University Northridge, jenghann.chong.43@my.csun.edu; Adit Ghosh, adit.ghosh.605@my.csun.edu; Scott Hauswirth, scott.hauswirth@csun.edu (Poster)

The 100-ft Rindge Dam situated along the Malibu Creek in Southern California is completely sediment-filled. A previous study indicated that the dam was filled with sediment within 34 years. Due to the environmental impact of the dam, there is an ongoing discussion regarding its removal. However, there are also arguments opposing the dam removal, including the potential for unfavorable downstream sediment transport and debris flows. Furthermore, there is limited sediment load data with only one gauging station in the watershed, ~3 km upstream of the dam. In this study, we use 1meter-DEM obtained from a LiDAR survey to estimate the sediment load along Malibu Creek that resulted in sedimentation of the reservoir and the potential effects of the possible future removal of the dam. We obtain the DEM of different cross-sectional profiles along the river using QGIS and automate the extraction of parameters, including slope, wetted perimeter, cross-sectional area, and discharge using MATLAB. We assume a constant discharge along the river to get the velocity and water stage at individual cross-sectional profiles to calculate the sediment discharge. We also compare with in-situ measurements of other rivers to determine the reliability of this method. Overall, we show that our method can be applied to other river basins with similar climate and water properties, which lack field data measurements.

BIO:

Jeng Hann, Chong was born and raised in Kuala Lumpur, Malaysia. Jeng Hann is currently pursuing a master's degree in geophysics at the California State University of Northridge. He graduated with a bachelor's degree in geology from the University of Maryland - College Park. His primary interest is to study geohazards related to earthquakes and landslides using geodetic methods such as remote sensing and GPS. Additionally, he is interested in science communication and public outreach programs.

CEU Evaluation Form