Bathymetry, lake area and volume mapping: A remote-sensing perspective
Book Chapter
Ayana, EK, Philpot, WD, Melesse, AM et al. (2014). Bathymetry, lake area and volume mapping: A remote-sensing perspective
. 9783319027203 253-267. 10.1007/978-3-319-02720-3_14
Ayana, EK, Philpot, WD, Melesse, AM et al. (2014). Bathymetry, lake area and volume mapping: A remote-sensing perspective
. 9783319027203 253-267. 10.1007/978-3-319-02720-3_14
A major challenge in constructing the storage characteristics for a lake is the inaccessibility to the shores due to operational limitation of survey campaigns. Lake bottom profiles are often extrapolated beyond the actual survey lines. The potential of satellite images to construct the storage characteristics of the shore areas is explored. Moderate-resolution Imaging Spectroradiometer (MODIS)-Terra images with 250- and 500-m resolutions are used to map the area of Lake Tana, Ethiopia, where daily-observed lake level data are available. The area estimates were obtained using two simple image calculation procedures: normalized difference vegetation index (NDVI) and normalized difference water index (NDWI)-enhanced NDVI (ENDVI). The lake level for each image day is used to reconstruct the shore bathymetry. The accuracy gains over the existing storage characteristics curve are evaluated by using the new shore bathymetric map to estimate lake levels. The result suggested that the existing bathymetric model is not applicable for the near-shore area where lake bottom depths are extrapolated. A new bathymetric model using MODIS images reproduced the water level with root-mean-square error (RMSE) of 0.20 m as compared to 0.87 m using the existing bathymetric model. Despite their coarser resolution, MODIS images can be a valuable tool for lake area mapping and can be used to improve lake storage measurement accuracy.
