Impact of dam height and grain size distribution on breaching of non-cohesive dams due to overtopping

The National Inventory of Dams reports 74,400 earthen dams in the United States in 2021; of these dams, approximately 27% are considered at high or significant hazard risk, that is dam failure will cause widespread damage and loss of lives. The most frequent cause of dam failure is breaching caused by overtopping. Accurate predictions of breach evolution are thus crucial to determine flood hydrographs for the safety of communities and properties at risk. Laboratory experiments were conducted on non-cohesive, compacted embankments to understand the role of dam height and sediment grain size on breaching caused by overtopping. Dam heights varied from 10 cm to 45 cm. Model structures were built with fine sand or with a mixture of fine sand and silt. Experiments showed that increasing dam height increases peak discharge. The presence of silt in model embankment material, on the contrary, lowers peak discharge and makes failure longer. In sand dams, sediment deposition on the downstream fac..., Breach hydrographs
The breach hydrographs were collected using sonar probes and a point gauge to measure the elevation of the upstream reservoir. An upstream weir was used to control the reservoir head and direct excess flow away from the dam. The head of water over the weir and known inflow discharge were used to compute the weir discharge. Conservation equations were then used to compute the discharge through the channel. The data had then been smoothed and poor data eliminated. 
Channel width
Two cameras monitored spatial and temporal changes in breach width. One camera was placed downstream of the dam to image the downstream dam face and a GoPro camera was placed just upstream of the dam to image the dam crest. Frames were extracted from the video recordings and manually digitized the dam geometry throughout the experiment. This digitized data could then be processed into temporal width data at varying locations along the downstream dam face and crest.
Channel depth/incision:
Breach..., Microsoft Excel to open all data.