Estimating uplift rate and erodibility from the area-slope relationship: Examples from Brittany (France) and numerical modelling

We used the local slope / drainage area relationship to derive the basic er osion and tectonic parameters from a topography. Assuming a dynamic equilib rium between uplift and erosion, this relationship is expected to depend qu ite simply on the rock erodibility, and on the tectonic uplift. This relati onship may then be used to quantify independently the effect of lithologica l variation on the erodibility, and the uplift rate. We tested the method o n a computer simulated topography and showed that the uplift information ca n be precisely calculated from the topographic analysis alone. We then anal ysed the topography of Brittany (France), and obtained a good agreement wit h uplift data from comparative levelling studies and river incision analysi s. (C) 2000 Elsevier Science Ltd. All rights reserved.