Late Quaternary landscape evolution of the Bergantes catchment: LAPSUS sensitivity in response to tectonic and lithological drivers

Over the past decade the FACSIMILE working group (Field And Computer Simulation In Landscape Evolution) has been working on the synergy between numerical modelling and field-based approaches. The past few years the FACSIMILE working group has been focussing their attention to one single catchment: the Bergantes river, a tributary of the Guadalope river, that drains the south-east part of the Ebro basin (Northeast Spain). Various experts in the fields of computer simulation, palaeohydrology, geochronology, geomorphology and sedimentology work together in an attempt to improve the synergy and understanding of the Late Quaternary landscape evolution of the Bergantes catchment over the past 140 Ka with a multidisciplinary approach.

The different computer simulation LEM approaches in the FACSIMILE working group mainly focus on erosion and sedimentation dynamics based on the published sedimentation history, stratigraphy and geochronology of the downstream river terrace staircase. Furthermore, important landscape evolution input datasets on palaeo-DEM and palaeo-climate have been reconstructed (see this conference). By working with comparable input datasets, especially the computer simulations of the different model approaches, become more easily comparable and straight forward particularly when compared to the field evidence presented so far.

The focus of this research is to analyse the sensitivity of LEM LAPSUS to 2 unexplored controlling driving factors so far; i) regional tectonics and ii) lithological differences in the Late Quaternary Bergantes landscape development. By constructing multiple-stage scenarios, the relative contribution of each of these factors is first estimated based on field observations, before their interaction is simulated. Although their effects are spatially different and they might vary one order of magnitude, we anticipate that both factors play a role individually and together in shaping the landscape in the Bergantes catchment. Consequently these results infer a further investigation for field evidence, which may be guided by these simulations. Especially by investigating key locations of the spatial explicit erosion and sedimentation rates of these scenarios. Finally, the results serve to inform the other LEM approaches on the need to incorporate these driving factors on lithology and tectonics.