Publications des scientifiques de l'IRD

Beaufort A., Carreau Julie, Sauquet E. (2019). A classification approach to reconstruct local daily drying dynamics at headwater streams. Hydrological Processes, 33 (13), p. 1896-1912. ISSN 0885-6087.

Titre du document
A classification approach to reconstruct local daily drying dynamics at headwater streams
Année de publication
2019
Type de document
Article référencé dans le Web of Science WOS:000470932200008
Auteurs
Beaufort A., Carreau Julie, Sauquet E.
Source
Hydrological Processes, 2019, 33 (13), p. 1896-1912 ISSN 0885-6087
Headwater streams (HSs) are generally naturally prone to flow intermittence. These intermittent rivers and ephemeral streams have recently seen a marked increase in interest, especially to assess the impact of drying on aquatic ecosystems. The two objectives of this work are (a) to identify the main drivers of flow intermittence dynamics in HS and (b) to reconstruct local daily drying dynamics. Discrete flow states-"flowing" versus "drying"-are modelled as functions of covariates that include information on climate, hydrology, groundwater, and basin descriptors. Three classifiers to estimate flow states using covariates are tested on four contrasted regions in France: (a) a linear classifier with regularization (LASSO for least absolute shrinkage and selection operator) and two non-linear non-parametric classifiers, (b) a one-hidden-layer feedforward artificial neural network (ANN) classifier, and (c) a random forest (RF) classifier. The three classifiers are compared with a benchmark classifier (BC) that simply estimates dominant flow state for each month based on observations (without using covariates). The performance assessment over the period 2012-2016 carried out by cross-validation shows that the three classifiers for flow state based on covariates outperformed the BC. This demonstrates the predictive power of the covariates. ANN is the classifier that globally achieves the best performance to predict the daily drying dynamics whereas both RF and LASSO tend to underestimate the proportion of drying states. The covariates are ranked in terms of relevance for each classifier. The monthly proportion of drying states provided by the discrete observation network has a major importance for the three classifiers ANN, LASSO, and RF. This may reflect the proclivity of a site to flow intermittence. ANN gives higher importance to climatic and hydrological covariates and its non-linearity allows a greater degree of freedom.
Plan de classement
Hydrologie [062] ; Informatique [122]
Description Géographique
FRANCE
Localisation
Fonds IRD [F B010076124]
Identifiant IRD
fdi:010076124
Contact