Evaluating surface and subsurface water storage variations at small time and space scales from relative gravity measurements in semiarid Niger
Artikel i vetenskaplig tidskrift, 2013

The acquisition of reliable data sets representative of hydrological regimes and their variations is a critical concern for water resource assessment. For the subsurface, traditional approaches based on probe measurements, core analysis, and well data can be laborious, expensive, and highly intrusive, while only yielding sparse data sets. For this study, an innovative field survey, merging relative microgravimetry, magnetic resonance soundings, and hydrological measurements, was conducted to evaluate both surface and subsurface water storage variations in a semiarid Sahelian area. The instrumental setup was implemented in the lower part of a typical hillslope feeding to a temporary pond. Weekly measurements were carried out using relative spring gravimeters during 3 months of the rainy season in 2009 over a 350 × 500 m2 network of 12 microgravity stations. Gravity variations of small to medium amplitude (≤220 nm s-2) were measured with accuracies better than 50 nm s-2, revealing significant variations of the water storage at small time (from 1 week up to 3 months) and space (from a couple of meters up to a few hundred meters) scales. Consistent spatial organization of the water storage variations were detected, suggesting high infiltration at the outlet of a small gully. The comparison with hydrological measurements and magnetic resonance soundings involved that most of the microgravity variations came from the heterogeneity in the vadose zone. The results highlight the potential of time lapse microgravity surveys for detecting intraseasonal water storage variations and providing rich space-time data sets for process investigation or hydrological model calibration/ evaluation.

magnetic resonance soundings

microgravimetry

groundwater

vadose zone

semiarid

surface water

Författare

Julia Pfeffer

Université de Strasbourg

Cédric Champollion

Université de Montpellier

Guillaume Favreau

IRD Montpellier

Bernard Cappelaere

IRD Montpellier

Jacques Hinderer

Université de Strasbourg

Marie Boucher

IRD Montpellier

Yahaya Nazoumou

Abdou Moumouni University

Monique Oï

IRD Montpellier

Maxime Mouyen

Université de Strasbourg

Academia Sinica

C Henri

IRD Montpellier

N. Le Moigne

Université de Montpellier

S. Deroussi

Université Paris Diderot

J. Demarty

IRD Montpellier

N. Boulain

University of Technology Sydney

N. Benarrosh

IRD Montpellier

O. Robert

Université Paris Diderot

Water Resources Research

0043-1397 (ISSN)

Vol. 49 6 3276-3291

Ämneskategorier

Vattenteknik

Havs- och vattendragsteknik

Annan naturresursteknik

DOI

10.1002/wrcr.20235

Mer information

Senast uppdaterat

2022-02-09