Publications des scientifiques de l'IRD

Mangiarotti Sylvain, Sekhar M., Berthon L., Javeed Y., Mazzega P. (2012). Causality analysis of groundwater dynamics based on a Vector Autoregressive model in the semi-arid basin of Gundal (South India). Journal of Applied Geophysics, 83, p. 1-10. ISSN 0926-9851.

Titre du document
Causality analysis of groundwater dynamics based on a Vector Autoregressive model in the semi-arid basin of Gundal (South India)
Année de publication
2012
Type de document
Article référencé dans le Web of Science WOS:000306455000001
Auteurs
Mangiarotti Sylvain, Sekhar M., Berthon L., Javeed Y., Mazzega P.
Source
Journal of Applied Geophysics, 2012, 83, p. 1-10 ISSN 0926-9851
Causal relationships existing between observed levels of groundwater in a semi-arid sub-basin of the Kabini River basin (Karnataka state, India) are investigated in this study. A Vector Auto Regressive model is used for this purpose. Its structure is built on an upstream/downstream interaction network based on observed hydro-physical properties. Exogenous climatic forcing is used as an input based on cumulated rainfall departure. Optimal models are obtained thanks to a trial approach and are used as a proxy of the dynamics to derive causal networks. It appears to be an interesting tool for analysing the causal relationships existing inside the basin. The causal network reveals 3 main regions: the Northeastern part of the Gundal basin is closely coupled to the outlet dynamics. The Northwestern part is mainly controlled by the climatic forcing and only marginally linked to the outlet dynamic. Finally, the upper part of the basin plays as a forcing rather than a coupling with the lower part of the basin allowing for a separate analysis of this local behaviour. The analysis also reveals differential time scales at work inside the basin when comparing upstream oriented with downstream oriented causalities. In the upper part of the basin, time delays are close to 2 months in the upward direction and lower than 1 month in the downward direction. These time scales are likely to be good indicators of the hydraulic response time of the basin which is a parameter usually difficult to estimate practically. This suggests that, at the sub-basin scale, intra-annual time scales would be more relevant scales for analysing or modelling tropical basin dynamics in hard rock (granitic and gneissic) aquifers ubiquitous in south India.
Plan de classement
Sciences fondamentales / Techniques d'analyse et de recherche [020] ; Hydrologie [062]
Description Géographique
INDE ; ZONE SEMIARIDE
Localisation
Fonds IRD [F B010057062]
Identifiant IRD
fdi:010057062
Contact