loading page

Comparison of methods to derive the height-area relationship of shallow lakes in West Africa using remote sensing
  • +7
  • Félix Girard,
  • Laurent Kergoat,
  • Hedwige Nikiema,
  • Maxime Wubda,
  • Roland Yonaba,
  • Tazen Fowé,
  • Amadou Abdourhamane Touré,
  • Ibrahim Maïnassara,
  • Mathilde de Fleury,
  • Manuela Grippa
Félix Girard
Géosciences Environnement Toulouse (Université de Toulouse, CNRS, IRD, CNES)

Corresponding Author:[email protected]

Author Profile
Laurent Kergoat
Géosciences Environnement Toulouse
Author Profile
Hedwige Nikiema
LERMIT, Universite Joseph Ki-Zerbo
Author Profile
Maxime Wubda
Université Joseph Ki-Zerbo, UFR-SVT/DST
Author Profile
Roland Yonaba
2iE Institute
Author Profile
Tazen Fowé
Laboratoire Eaux, Hydro-Systèmes et Agriculture (LEHSA), Institut International d'Ingénierie de l'Eau et de l'Environnement (2iE)
Author Profile
Amadou Abdourhamane Touré
Université Abdou Moumouni, Faculté des Sciences et Techniques, Département de Géologie
Author Profile
Ibrahim Maïnassara
IRD, Représentation au Niger
Author Profile
Mathilde de Fleury
Géosciences Environnement Toulouse (Université de Toulouse, CNRS, IRD, CNES)
Author Profile
Manuela Grippa
Géosciences Environnement Toulouse, Univ. Toulouse, CNRS, IRD, CNES
Author Profile

Abstract

In West Africa, lakes and reservoirs play a vital role as they are critical resources for drinking water, livestock, irrigation and fisheries. Given the scarcity of in situ data, satellite remote sensing is an important tool for monitoring lake volume changes in this region. Several methods have been developed to do this using water height and area relationships, but few publications have compared their performance over small and medium-sized lakes. In this work we compare four methods based on recent data from the Pleiades, Sentinel-2 and -3, ICESat-2 and GEDI missions over 16 lakes in the Central Sahel, ranging in area from 0.22 km² to 21 km². All methods show consistent results and are generally in good agreement with in situ data (height RMSE and volume NRMSE mostly below 0.30m and 11% respectively). The obtained height-area relationships show very little noise (fit RMSD mostly below 0.10m), except for the Sentinel-3-based method which tends to produce higher dispersion. The precision of the estimated water height is about 0.20m for Pleiades Digital Surface Models (DSMs) and less than 0.13m for the other methods. In addition, fine shape patterns are consistently observed over small height amplitudes, highlighting the ability to monitor shallow lakes with non-linear bathymetric behavior. Inherent limitations such as DSM quality, temporal coverage of DSM and lidar data, and spatial coverage of radar altimetry data are identified. Finally, we show that the combination of lidar and radar altimetry-based methods has great potential for estimating water volume changes in this region.
05 Mar 2024Submitted to ESS Open Archive
13 Mar 2024Published in ESS Open Archive