Lake level variations and global hydrological change: A spatio-temporal analysis.

Abstract

Variations in the global hydrological cycle occur at many time and space scales. An important source of evidence about past variations in the hydrological balance are records of lake level fluctuations. The spatial extent and depth of a lake varies in response to changes In the water balance over its surface and catchment. These variations may result from local factors or climate change. However, spatial climatically-induced patterns can be identified when most lakes in a region change in a similar way. A global lake-level database was constructed from three previously developed databases, and used to investigate large-scale patterns present in the lake-level data during the Holocene. Using the geostatistical approach, regional patterns were objectively identified by examining the spatial correlation between sites and gridded using ordinary and indicator kriging at 3,000 year intervals. These maps were produced using two assumptions. First, the data were used under the assumption that climate is continuous in space, and hence, the data were treated as spatial continuous interval data. Then, the data were used under the assumption that the data is spatial categorical and that the classes are mutually exclusive. (Abstract shortened by UMI.)