I'm seeking some guidance as I develop my PhD dissertation. I had planned on using a geomorphological mapping approach (remote sensing, terrain modeling, and field mapping) to map landforms and processes operating at different spatial scales to understand the spatial distribution (pattern) and interaction of landforms at different stages of placer development (placer diamonds). I'm interested in addressing this issue from the watershed scale since much work has been done at the reach scale with the physics-based approach. I need to narrow down my focus and address specific scientific questions and am seeking advice.