Reanalysis of monthly precipitation fields in colombian territory

Abstract

The historical monthly precipitation fields in Colombia are estimated and studied for the period 1975 - 2006 at a spatial resolution of 5 minutes of arc, calculated using an optimal integration of information available at rain gauges and distributed monthly series of fields from satellite measurements and studies of reanalysis at different periods and various spatial resolutions. Space interpolation of point observations uses a variant of the PRISM model [1]. Based on a MDT, the relationship between precipitation and topography was studied, allowing the development and implementation of a model of interpolation similar to PRISM to estimate monthly precipitation fields. Considering the topographic effect as the most important factor in explaining the spatial variability of rainfall, the study area is discretized in homogeneous regions that allowed to represent adequately the presence of the pluviometric optimal height and the temporal variability imposed by the ITCZ.