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Advances in Meteorology
Volume 2013 (2013), Article ID 237126, 9 pages
http://dx.doi.org/10.1155/2013/237126
Research Article

Spatial Downscaling of TRMM Precipitation Using Geostatistics and Fine Scale Environmental Variables

Department of Geoinformatic Engineering, Inha University, Incheon 402-751, Republic of Korea

Received 6 September 2013; Revised 19 November 2013; Accepted 27 November 2013

Academic Editor: Chung-Ru Ho

Copyright © 2013 No-Wook Park. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

A geostatistical downscaling scheme is presented and can generate fine scale precipitation information from coarse scale Tropical Rainfall Measuring Mission (TRMM) data by incorporating auxiliary fine scale environmental variables. Within the geostatistical framework, the TRMM precipitation data are first decomposed into trend and residual components. Quantitative relationships between coarse scale TRMM data and environmental variables are then estimated via regression analysis and used to derive trend components at a fine scale. Next, the residual components, which are the differences between the trend components and the original TRMM data, are then downscaled at a target fine scale via area-to-point kriging. The trend and residual components are finally added to generate fine scale precipitation estimates. Stochastic simulation is also applied to the residual components in order to generate multiple alternative realizations and to compute uncertainty measures. From an experiment using a digital elevation model (DEM) and normalized difference vegetation index (NDVI), the geostatistical downscaling scheme generated the downscaling results that reflected detailed characteristics with better predictive performance, when compared with downscaling without the environmental variables. Multiple realizations and uncertainty measures from simulation also provided useful information for interpretations and further environmental modeling.