Estimation of daily design rainfall in Argentina from satellite-derived data

Abstract

The results of the estimation of the daily design rainfall in Argentina are presented for 97 % of the continental national territory. This analysis was based on the processing of the Satellite-Derived Precipitation Data (DPDS) of the CHIRPS product (Climate Hazards Group InfraRed Precipitation with Station data), with a spatial resolution of 5 km and a temporal coverage of 37 years. The extraction of the Annual Maximum Daily Precipitation (pdMa) maps was carried out by means of ad-hoc codes developed through the Google Earth Engine platform. The pdMa series from CHIRPS were compared with those obtained from 64 rainfall stations provided by the National Meteorological Service (SMN), determining the slopes of the linear regression. These regression parameters were interpolated to the territory under study, to enhance the pdMa maps. These corrected maps were processed through codes developed in Python, to associate non-exceedance empirical probabilities and adjust the optimal theoretical probability distribution to each of the 106 778 pixels considered. From these results, daily design rainfall maps were generated for 2-100-year return periods. These results were validated against 30 stations from the National Water Information System, obtaining an acceptable agreement. It is considered that the results obtained will be useful in hydrological design, especially in regions that lack adequate rainfall records for a traditional statistical analysis.