Mobile Evaporite Enhances Cycle of Physico-chemical Erosion in Badlands

Erosion-induced weathering is significant control of Earth’s surface process, however, the impacts of extreme weather on chemical weathering dynamics are poorly understood. Badland landscapes formed with highly erodible, homogeneous substrates have the potential to respond measurably to the individual event on scales that are open to direct observation. Here, using the high temporal resolution of suspended sediment and riverine chemistry records in the badland basin in southwestern Taiwan, we assess the mineralogical, geochemical and grain-size composition features that can be used to quantify landscape response to erosion drivers. During the typhoon period, sodium adsorption ratio is covariant with suspended sediment concentration, which can be assigned to sodium-induced dissolution. Further, sodium and calcium of suspended sediment account for about 10 % of the mass loss in this event, and the current-induced dissipation may be responsible for it. Plus, water chemistry is dominated by silicate weathering at 18 ton/km²/day. We expect that the observation of physico-chemical reactions in badlands provides a deeper explanation of coupling of hillslope-channel landscape within erosional cycle.