Potential Aeolian Sediment Transport Pathways, Provenance, and Landscape Evolution in the Chuckwalla Valley, Southeastern California.

Sediment transport by wind is one of the fundamental processes redistributing mass across planetary surfaces. However, there is a great deal of uncertainty surrounding aeolian processes, and how they interact with landscapes and other mass transport processes, much of it stemming from a lack of data. Over short timescales, this transport can negatively impact infrastructure, and here we seek to better understand potential impacts to the Riverside East Solar Energy Zone in the Chuckwalla Valley. To address this, we present preliminary results concerning field data-driven sediment transport modeling, geochemical aeolian sediment provenance, Optically Stimulated Luminescence dating, and landscape evolution modeling from the Chuckwalla Valley of Southeastern California. The Chuckwalla Valley is an excellent example of an aeolian landscape with sand ramps, dune fields, and active sediment transport interspersed with human infrastructure such as the Riverside East Solar Energy Zone managed by the Bureau of Land Management.

We collect wind speed, temperature, and precipitation data from a weather station installed over a multi-month period in 2018 and couple this data with particle size measurements to calculate the range in sediment transport rates over our observation interval. We also present preliminary geochemical analysis on samples collected from the Chuckwalla Valley to identify sediment provenance and constrain the timing of sediment deposition using OSL dating. These data are in turn used to inform a landscape evolution model. For this model, we use the landlab 1.0 toolkit for Python 3.4 to combine fluvial erosion and sediment transport using the SPACE model with our newly built components for wind-blown sediment transport flux and wind deflection by topography Further refinements will come from extending our time series of weather station measurements and additional characterization of the distribution of aeolian sediment provenance, sediment-transport pathways, landscape-surface stability time scales, and landscape-evolution processes that are likely to affect the potential for viability of infrastructure in areas such as the Riverside East Solar Energy Zone. Broadly, our data will help address knowledge gaps in aeolian sediment dynamics.