Author(s): Bellie Sivakumar; Fitsum M. Woldemeskel; Vijay P. Singh
Linked Author(s):
Keywords: Rainfall; Spatial variability; Interpolation; Correlation; Scale; Threshold
Abstract: Rainfall data at fine spatial resolutions are needed for various applications in the fields of hydrology, water resources, and environment. However, high spatial resolution rainfall data are not widely available, especially in developing regions. A common practice to obtain such data is through interpolation, based on rainfall data available at coarser resolutions or nearby points. A fundamental assumption in the development of many of the interpolation schemes is the existence of correlation in rainfall across space, with nearby points considered to be more correlated than distant ones. Although this assumption is reasonable, it is also important to note that rainfall correlation alone is not sufficient to examine the spatial rainfall estimation problem, since other factors (e. g. scale, threshold) also play important roles. In the present study, we propose a methodology that combines rainfall correlations, spatial scale, and correlation thresholds for representing spatial rainfall correlations in a region. We apply this method to high-quality monthly rainfall data at a resolution 0. 25° x 0. 25° latitude/longitude across Australia. Important implications of the results are also discussed.
Year: 2013