TY  - JOUR
A1  - Roda-Boluda, Duna C.
A1  - McDonald, Jordan
A1  - Whittaker, Alexander C.
A1  - D'Arcy, Mitchell
T1  - Lithological controls on hillslope sediment supply
BT  - insights from landslide activity and grain size distributions
JF  - Earth surface processes and landforms : the journal of the British Geomorphological Research Group
N2  - The volumes, rates and grain size distributions of sediment supplied from hillslopes represent the initial input of sediment delivered from upland areas and propagated through sediment routing systems. Moreover, hillslope sediment supply has a significant impact on landscape response time to tectonic and climatic perturbations. However, there are very few detailed field studies characterizing hillslope sediment supply as a function of lithology and delivery process. Here, we present new empirical data from tectonically-active areas in southern Italy that quantifies how lithology and rock strength control the landslide fluxes and grain size distributions supplied from hillslopes. Landslides are the major source of hillslope sediment supply in this area, and our inventory of similar to 2800 landslides reveals that landslide sediment flux is dominated by small, shallow landslides. We find that lithology and rock strength modulate the abundance of steep slopes and landslides, and the distribution of landslide sizes. Outcrop-scale rock strength also controls the grain sizes supplied by bedrock weathering, and influences the degree of coarsening of landslide supply with respect to weathering supply. Finally, we show that hillslope sediment supply largely determines the grain sizes of fluvial export, from catchments and that catchments with greater long-term landslide rates deliver coarser material. Therefore, our results demonstrate a dual control of lithology on hillslope sediment supply, by modulating both the sediment fluxes from landslides and the grain sizes supplied by hillslopes to the fluvial system.
KW  - lithology
KW  - hillslopes
KW  - landslides
KW  - grain size
KW  - sediment supply
Y1  - 2018
U6  - https://doi.org/10.1002/esp.4281
SN  - 0197-9337
SN  - 1096-9837
VL  - 43
IS  - 5
SP  - 956
EP  - 977
PB  - Wiley
CY  - Hoboken
ER  -