Debris-flow inundation and damage data from the 9 January 2018 Montecito Debris-Flow Event

On 9 January 2018, intense rain above Montecito, California triggered a series of debris flows from steep catchments in the Santa Ynez Mountains. These catchments were burned three weeks earlier by the 1140 km2 Thomas Fire. After exiting the mountain front, the debris flows traveled over 3 km down a series of alluvial fans, killing 23 people and damaging over 400 homes. To understand the flow dynamics and damage of the debris flows and to provide a data set for testing debris-flow runout models, we mapped the inundation characteristics of the five main debris-flow runout paths in Montecito. Here we present our map data on the boundaries of debris-flow inundation, flow depth, and deposit characteristics and link these observations to a CAL FIRE inventory of building damage. The data include geo-tagged photos of debris-flow deposits and damage throughout the runout paths. Each photo is associated with a single object in the geodatabase. Note that there are often multiple photos taken with different perspectives from the same location. The data accompany an interpretive paper published in the journal Geosphere. The full citation for this interpretive paper is: Kean, J.W., Staley, D.M., Lancaster, J.T., Rengers, F.K., Swanson, B.J., Coe, J.A., Hernandez, J.L., Sigman, A.J., Allstadt, K., and Lindsay, D.N., 2019, Inundation, flow dynamics, and damage in the 9 January 2018 Montecito debris-flow event, California, USA: Opportunities and challenges for post-wildfire risk assessment, Geosphere, v. 15, https://doi.org/10.1130/GES02048.1.