Disponibilidade de horas de frio na região central do Rio Grande do Sul: 2 - Distribuição geográfica Chilling hours in the central region of Rio Grande do Sul state: 2 - Geographic distribution

Abstract

Foram traçadas as cartas da distribuição de disponibilidade de horas de frio na região Central do Rio Grande do Sul. Para tal, utilizaram-se os dados de disponibilidade de ocorrência do número médio acumulado de horas de frio Maps of chilling hours distribution in the central region of Rio Grande do Sul, Brazil, were drawn. Mean of chilling hours bellow 7°C (HF<7) and 13°C (HF<13) accumulating every 15 days up to certain date were used. Isolines of different intensities were drawn using average accumulated values of the number of chilling hours for the occurrence probability of 50%. Two distribution combinations were used to determine the occurrence probability of chilling hours. One was a discrete distribution to verify if there was chilling hours accumulated during the 15 day interval and the other one was a continuous distribution used to identify the accumulate chilling hours. Regression equations that adjusted chilling hours values as a function of the local latitude and altitude were used to simplify isolines drawing. Lower values of accumulate chilling hours below 7°C and below 13°C were observed in locals with low altitudes, such as Jacuí, Vacacaí and Ibicuí river valleys and main tributary streams. However, higher values were observed in high altitudes mainly in Serra do Sudeste and Planalto highland areas.

Keywords

• cartas climáticas
• horas de frio
• frutíferas caducifóleas
• chilling hours
• deciduous fruit tree
• regional distribution maps