An Integrated Approach to Predict Outflow Hydrograph Due to Landslide Dam Failure by Overtopping and Sliding

Abstract

Formation and failure of landslide dam are one of the significant natural hazards in the mountainous area all over the world. In the event of catastrophic failure of landslide dam, we have to predict resulting outflow hydrograph. It will serve as an upstream boundary condition for subsequent flood routing to predict flood hazard in the downstream. Most of the existing models are applicable to overtopping failure of landslide dam. In this study an attempt has been made to incorporate integration of three separate models to predict the outflow hydrograph resulted from failure of landslide dam by overtopping and sudden sliding through flume experiments and numerical simulations. The main advantage of an integrated model is that it can detect failure mode due to either overtopping or sliding based on initial and boundary conditions. The proposed model is tested for three different experimental cases of landslide dam failure due to overtopping and sliding and reasonably reproduced the resulting hydrograph.

Valley formation by groundwater seepage, pressurized groundwater outbursts and crater-lake overflow in flume experiments with implications for Mars

“…In addition, these experiments also have similar characteristics as dam removal or failure events (e.g. Chen and Simons, 1979;Cantelli et al, 2004;Awal et al, 2008). The experiments by Cantelli et al (2004) show an initial narrowing at the dam during quick incision, followed by widening as incision ceases.…”

“…In our experiments, the channel at the rim narrows during the incision and widens afterwards but to lesser amount than in the case of dam removal because the incision relative to the channel depth is smaller on the gentle crater rim slopes compared to the steep and thick artificial dams. Awal et al (2008) used numerical modeling and physical experiments to predict the outflow hygrograph of a dam failure. They studied both failure of the dam by overtopping and by slumping of the dam.…”

Natural dam failure in slope failure mode triggered by seepage

“…This implies that we cannot reasonably rule out the influence of above parameters on the failure modes of natural dams. The parameters Ks and inflow rate are important to determine the failure mode type of the natural dam, as Gregoretti et al (2010) and Awal et al (2008) suggested. Therefore, the parameters q in and Ks should be considered when determining the failure mode types of natural dams.…”

“…Jiang et al (2018) analyzed the influence of the downstream slope, infiltration coefficient, and inflow rate on the slope failure mode of natural dams, but the analyses were basic and simple. Awal et al (2008) considered that the downstream slope of the dam and infiltration coefficient were the main factors controlling the slope failure modes. In this analysis, the influence of materials is considered insufficiently.…”

Performance of Models for Flash Flood Warning and Hazard Assessment: The 2015 Kali Gandaki Landslide Dam Breach in Nepal

“…This event is just one example of the frequent flash floods experienced in Nepal. In addition to landslide dam breaching (Weidinger 2006;Awal 2008aAwal , 2008b, flash floods can be caused by intense rainfall events in steep mountainous areas, rockfall induced by glacial melting (Bhandary et al 2012), or glacial lake outburst floods (Bajracharya et al 2007). Rapid prediction of flood arrival time and depth is essential for issuing timely warnings to downstream population centers, yet it is often compromised by lack of the data that would make it possible to run simulations with the increasingly sophisticated hydrodynamic models available today (Schwanghart et al 2016).…”