Yoyok Adisetio Laksono, Siti Zulaikah, Sutrisno, Zulkifli Yusop, Daeng Ahmad Suaidi, Abdulloh Fuad, Moch Bagas Setya Rahman, Qorny Faren Anggana
The monitoring found the seepage at the wall canal at downstream foothill in the Selorejo dam. It is a sign that there is water leakage from the dam. To better understand the path of leakage water, some locations of the dam were scanned using 90 MHz radar. The scanning location was done at three locations, namely at (1) the top, (2) the middle slope downstream hill, and (3) the downstream foothill dam using profiling. All those locations were scanned using the B-scan technique. The methods of analysis employed in this research were a gain profile, bandpass filter, and average subtraction to see the radargram clearly. The results found that there are two paths of seepage that started from the top dam. This path shows clearly at the middle slope dam, and this path is unified along before foothill downstream. It implies that seepage might be an early stage of the internal erosion process. © 2020 Author(s).
Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Negeri Malang, Jl. Semarang No. 5, Malang, 65145, Indonesia; Centre for Environmental Sustainability and Water Security (IPASA), Faculty of Civil Engineering, Universiti Teknologi Malaysia, Malaysia