Global gridded dataset of lake coverage and lake depth for use in numerical weather prediction and climate modelling

ABSTRACT

A global dataset of lake coverage and lake depth was developed for use in numerical weather prediction and climate modelling. It provides the global gridded information on lake depth with the resolution of 30 arc sec. (approximately 1 km). It was obtained by mapping data on mean lake depth for ca. 13 000 freshwater lakes. Apart from the mean depth, the bathymetry for 36 large lakes is included. Information for individual lakes was collected from regional databases, water cadastres and public sources. For mapping, the land cover map ECOCLIMAP2 was used. A new automatic probabilistic mapping method was developed and is described here. We discuss also how to project the lake depth data onto the numerical atmospheric model grid and how to achieve the consistency of physiographic datasets when several maps are used in a model.

• parameterization of lakes
• surface processes
• physiographic data

7. Acknowledgements

The authors thank Suleiman Mostamandi and Sergey Kondratiev (Russian State Hydrometeorological University) for the help with digitising the bathymetry, Dmitrii Mironov (Deutscher Wetterdienst), Patrick Samuelsson (Swedish Meteorological and Hydrological Institute) and Patrick Le Moigne (Météo-France) for useful discussions. Special thanks to Vladimir Kurzenev and Alina Barbu for discussions on mathematical aspects of the mapping method. Two anonymous reviewers made many useful remarks. The dataset for individual lakes was made possible by people who kindly provided lake data, their names are listed in the dataset header. The project was supported by COSMO, Deutscher Wetterdienst, by the HIRLAM consortia and by Météo-France.

Notes

¹In fact, it is not correct because with a certain map resolution, some lakes with long narrow straits may break down into several non-conterminal areas.

²Although this assumption is not always true.

³Here we ignore the resolution issue and assume that the pixel belongs to the lake entirely.