Precipitation and rainwater pH spatial distribution in Bahía Blanca and Tandil, Argentina

CAMPO A.; ZAPPERI, P.; PICONE, N.

Dublin

Congreso; 8 International Conference Urban Climate; 2012

Abstract Microscale climate variation produced by urban areas are called urban climate. While the occurrence of rainfall is a regional scale phenomenon, cities influence on precipitation spatial distribution patterns and their characteristics. These influences had been studied for a very long time especially in the Northern Hemisphere. Tandil and Bahía Blanca are middle cities of Argentina located in the South of Buenos Aires province. Both present continental template climate. The aim of this research is to analyze the spatial distribution patterns of precipitation and the rainwater pH values for the period October 2010 - September 2011 in Tandil and Bahía Blanca. Gauge rain nets were installed in both cities. In each event of precipitation amount and pH values were recollected. Isohytes plotting was included in the thematic cartography that was made using ArcGis 9.3 ® software. Although natural rains are generally considered as being weakly acid, the rainwater pH measurements demonstrated that in both cities the rain is alkaline. Regarding to the spatial distribution of the precipitation amounts, the isohyets of the annual records showed that the highest values were registered in areas of higher elevation, South-Southwest zones in Tandil and North-Northeast areas in Bahía Blanca, instead the lowest values where presente in the downtown. Key words: precipitation - pH ? Bahía Blanca - Tandil.