Classification of worldwide drainage basins through the multivariate analysis of variables controlling their hydrosedimentary response

• Published in: Global and Planetary Change
• Main Authors: Raux, Julie, Copard, Yoann, Laignel, Benoît, B., Fournier, Matthieu, Massei, Nicolas
• Other Authors: Morphodynamique Continentale et Côtière (M2C), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2011
• Subjects: Cluster Analysis (CA); sediment load; Principal Component Analysis (PCA); river discharge; drainage basin; [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; [SDE.MCG]Environmental Sciences/Global Changes; Arctic
• Online Access: https://hal.science/hal-00861218; https://doi.org/10.1016/j.gloplacha.2010.12.005

International audience Quality and amount of waters and sediments conveyed within large drainage basins are crucial for human societies and biodiversity concerns. This work aims to determine the factors controlling the hydrosedimentary response (water discharge and sediment load) of 24 worldwide large drainage basins. In this respect, eleven geomorphologic and climatic variables routinely used in the literature were considered and others as fractal dimension, elongation and mean channel slope are novel for such an issue. In addition, two variables, land cover and lithology indexes, somewhat different from the literature in terms of calculation principles, were also included. All these variables were then subjected to multivariate statistical analyses (CA and PCA) and confronted in a matrix correlation. On the whole, our results display that water discharge is controlled by runoff, precipitation, basin area, elongation and fractal dimension while sediment load is governed by runoff, precipitation and maximum elevation. Mean channel slope and land-use have a minor role while other parameters (hypsometry, lithology, length, slope, mean elevation and temperature) do not play a significant role in the hydrosedimentary response. Such statistical analyses also bring out a classification of these drainage basins, comprising five to six main clusters which are ranged according to the main variables ruling their hydrosedimentary response. Two clusters are essentially governed by geomorphometric parameters (area, elongation, fractal dimension, mean elevation and hypsometry) while one cluster is rather controlled by transfer processes (runoff) and by active tectonic (maximum elevation). Hydrosedimentary response of arctic and continental rivers is controlled by low temperature while two drainage basins show any trend. A comparison of our results with other previous works dealing with this same issue points to some significant disagreements essentially based on the number of drainage basins considered, the number of nature ...