TY - JOUR
T1 - Hydraulic Causes for Basin Hydrograph Skewness
AU - Collischonn, Walter
AU - Fleischmann, Ayan
AU - Paiva, Rodrigo C.D.
AU - Mejia, Alfonso
N1 - Publisher Copyright:
© 2017. American Geophysical Union. All Rights Reserved.
PY - 2017/12
Y1 - 2017/12
N2 - It has been suggested that hydrograph skewness depends on the relative dominance between hillslope and channel network transport processes, where the former ones make the hydrograph positively skewed while the latter tends to make it negatively skewed. More recently, however, the role of river hydraulics in shaping the hydrograph has been highlighted. We present a set of numerical modeling experiments using a hydrodynamic model of river networks in which we investigate how channel hydraulics influence the shape of the hydrograph, particularly its skewness. We further investigate the influence of base flow, rainfall intensity, cross section geometry, and basin scale on unit hydrograph response. We show that river hydraulics has a decisive role because positively skewed hydrographs may occur even when water inputs to the river network are negatively skewed, and in catchments whose width function is also negatively skewed. We show additional results related to the effect of the degree of nonlinearity in the relationship between celerity and discharge, the effects of base flow and rainfall intensity. These further confirm that hydraulic factors may be decisive in determining hydrograph shape.
AB - It has been suggested that hydrograph skewness depends on the relative dominance between hillslope and channel network transport processes, where the former ones make the hydrograph positively skewed while the latter tends to make it negatively skewed. More recently, however, the role of river hydraulics in shaping the hydrograph has been highlighted. We present a set of numerical modeling experiments using a hydrodynamic model of river networks in which we investigate how channel hydraulics influence the shape of the hydrograph, particularly its skewness. We further investigate the influence of base flow, rainfall intensity, cross section geometry, and basin scale on unit hydrograph response. We show that river hydraulics has a decisive role because positively skewed hydrographs may occur even when water inputs to the river network are negatively skewed, and in catchments whose width function is also negatively skewed. We show additional results related to the effect of the degree of nonlinearity in the relationship between celerity and discharge, the effects of base flow and rainfall intensity. These further confirm that hydraulic factors may be decisive in determining hydrograph shape.
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U2 - 10.1002/2017WR021543
DO - 10.1002/2017WR021543
M3 - Article
AN - SCOPUS:85040833379
SN - 0043-1397
VL - 53
SP - 10603
EP - 10618
JO - Water Resources Research
JF - Water Resources Research
IS - 12
ER -