A novel spatial downscaling approach for climate change assessment in
regions with sparse ground data networks
Abstract
This study proposes a novel approach that expands the existing QDM
(quantile delta mapping) to address spatial bias, using Kriging within a
Bayesian framework to assess the impact of using a point reference
field. Our focus here is to spatially downscale daily rainfall sequences
simulated by regional climate models (RCMs), coupled to the proposed
QDM-spatial bias-correction, in which the distribution parameters are
first interpolated onto a fine grid (rather than the observed daily
rainfall). The proposed model is validated through a cross‐validatory
(CV) evaluation using rainfall data from a set of weather stations in
South Korea and climate change scenarios simulated by three alternate
RCMs. The results demonstrate the efficacy of the proposed model to
simulate the bias-corrected daily rainfall sequences over large regions
at fine resolutions. A discussion of the potential use of the proposed
approach in the field of hydrometeorology is also offered.