CHARACTERIZATION OF A MASS-WASTING EVENT DURING THE AUGUST 2, 2022, STORM AT VESA CREEK, KLAMATH MOUNTAINS, CALIFORNIA

The 2022 McKinney Fire burned 60,138 acres near Highway 96, southwest of the Klamath River in Siskiyou County, California. August 2, 2022, thunderstorms triggered mass-wasting events in the tributaries along the Klamath River. Aerial Imagery and terrain data were provided and collected by Yurok Tribe Fisheries Department, then used in Global Mapper GIS software to identify erosional and depositional features in the Vesa Creek watershed. To assess the character of these features with respect to their locations and attributes, such as slope gradient, aspect, and length. I considered the roles of burned severity, 3-hour rainfall accumulation, and basin geology for the erosion formation. The purpose of this study is to characterize the style and amount of mass-wasting features in the Vesa Creek watershed. The rills that coalesced into gullies were the dominant erosion feature in the Vesa Creek watershed. Erosional features were prominent on the north and east facing slopes with high to moderate burn severity, moderate to high steepness, low to moderate rainfall accumulation, and geology consisted of weathered diotitic rocks and schist. The deposition was more prominent in the lower regions of the watershed where the slope gradients were low. I interpreted the rills, gullies, and mass-wasting deposits in the main stem of Vesa Creek to indicate hillslope erosion started as a hyperconcentrated flow and then transitioned into a debris flow.