Movie 2: Sample GSFast results: an incorporation of the Fedele and Paola (2007) self-similar grain size model into multiple dimensions (Across basin, down basin, and over time/depth) within the Fastscape landscape evolution model. Although only the basin area has been plotted, an uplifting mountain catchment (source) area to the left (on the long profile) is feeding into a subsiding basin that is draining (sink) towards the right. Reference: Fedele & Paola. (2007). JGR: ES 112(F2).
We have generalized the Fedele and Paola (2007) self-similar model into three dimensions (across the basin, downstream, and over time) by removing the river length scaling and incorporating this grain size approach into the Fastscape landscape evolution model. Our three-dimensional approach to grain size fining (GSFAST) has shown that channel mobility in the alluvial basin strongly alter the deposition and grain size fining rate in a way unaccounted for using fewer dimensions. The implications of a landscape evolution model containing substrate grain size in three dimensions are in the model's application to constrain the environmental forcing conditions that would be plausible to produce observed field data. However, in our future work, we will need to first quantify what controls the avulsion rate in the model and compare this to the avulsion frequency in natural systems before applying GSFAST to interpret grain-size data. Reference: Fedele & Paola. (2007). JGR: ES 112(F2).
(c) Amanda Wild