@article{fdi:010063708,
  title = {{C}ontrasting mountain and piedmont dynamics of sediment discharge associated with groundwater storage variation in the {B}iobio {R}iver},
  author = {{T}olorza, {V}. and {C}arretier, {S}{\'e}bastien and {A}ndermann, {C}. and {O}rtega-{C}ulaciati, {F}. and {P}into, {L}. and {M}ardones, {M}.},
  editor = {},
  language = {{ENG}},
  abstract = {{S}upply and transport of sediment in catchments involve processes with fundamental consequences for river management, land use, and the prediction of climate-driven sediment fluxes. {I}n the present study we addressed spatial variability in the water routes through the surface and subsurface of a catchment and the suspended sediment discharge ({Q}(s)) over a mountain-piedmont system. {W}e analyzed daily suspended sediment concentration ({C}-s) and water discharge ({Q}) measurements at stations located in different topographic settings (mountain and piedmont) in the {B}iobio {R}iver basin (southern central {A}ndes, 37-39 degrees {S}). {I}n steep catchments, the {Q} versus {Q}(s) relationship has a marked seasonal hysteresis. {I}n the piedmont, {Q}(s) is proportional to {Q}, with no seasonal hysteresis. {T}he contrast in the hysteresis pattern between catchments with different topographies is explained by differences in the routing of rainfall-derived water. {I}n the piedmont, most of the rainfall is converted into surface runoff because the water table is near the surface. {I}n the mountains, groundwater storage results in large seasonal variations in the proportion of {Q} that flows at the surface and transports sediment from the hillslopes, producing hysteresis. {B}y separating the total {Q} into two components (direct discharge, {Q}(d) and base flow, {Q}(b)), we observed the response of {Q}(s) to the fraction of water that quickly leaves the catchment after a rainfall event ({Q}(d)). {S}imilar results between the mountain and piedmont and the absence of hysteresis simplify the behavior of {Q}(s) into a linear relationship with {Q}(d) over the entire catchment and lead us to propose that sediment mobilization to the river along the {B}iobio catchment is primarily controlled by overland flow. {O}ur findings highlight the importance of an adequate hydrological model for understanding the erosion and transport processes of a catchment, and which can be applied to other natural and modeled mountain-piedmont systems.},
  keywords = {sediment flux dynamics ; catchment erosion ; {B}iobio {R}iver ; {CHILI} ; {ANDES}},
  booktitle = {},
  journal = {{J}ournal of {G}eophysical {R}esearch. {E}arth {S}urface},
  volume = {119},
  numero = {12},
  pages = {2730--2753},
  ISSN = {2169-9003},
  year = {2014},
  DOI = {10.1002/2014jf003105},
  URL = {https://www.documentation.ird.fr/hor/fdi:010063708},
}