Subsidy For Prevention And Fighting In Forest Fires Based On The Precipitation Behavior In Irati National Forest, Paran\ue1

Este trabalho foi desenvolvido na Floresta Nacional de Irati localizada, predominantemente, no munic\uedpio de Fernandes Pinheiro, Paran\ue1, com base em dados meteorol\uf3gicos de precipita\ue7\ue3o pluviom\ue9trica di\ue1ria, no per\uedodo de 1963 a 2006. Teve como objetivo analisar os aspectos do comportamento da precipita\ue7\ue3o, com a finalidade de utilizar esse par\ue2metro no planejamento de preven\ue7\ue3o e combate aos inc\ueandios florestais, em tal unidade de conserva\ue7\ue3o, sobretudo no que diz respeito \ue0 defini\ue7\ue3o do per\uedodo normal de inc\ueandios e sua influ\ueancia sobre o perigo de inc\ueandios florestais. Foram analisados a precipita\ue7\ue3o mensal, o n\ufamero de dias de chuva e a precipita\ue7\ue3o m\ue9dia por dia de chuva (mm) em termos de seus valores m\ue9dios, m\uednimos e m\ue1ximos, para o per\uedodo de 1963 a 2005. Posteriormente, esses dados foram agrupados, tendo sido feito um estudo da evolu\ue7\ue3o da precipita\ue7\ue3o para esses per\uedodos. Foram determinadas e analisadas as variabilidades interanual dos per\uedodos seco e chuvoso, para um per\uedodo de 44 anos. Observouse: a) que o per\uedodo normal de inc\ueandios se concentra nos meses de abril a agosto, per\uedodo de menor precipita\ue7\ue3o m\ue9dia mensal; b) um aumento da precipita\ue7\ue3o anual; c) diminui\ue7\ue3o no n\ufamero de dias de chuva por ano; e d) aumento da precipita\ue7\ue3o m\ue9dia por dia de chuva. Esses aspectos tamb\ue9m foram notados quando analisados por per\uedodos, tendo ocorrido o aumento de 128,78 mm na precipita\ue7\ue3o total anual m\ue9dia; um decr\ue9scimo de cerca de 3 dias de chuva e um acr\ue9scimo de 0,90 mm de precipita\ue7\ue3o m\ue9dia por dia de chuva, no per\uedodo considerado. O in\uedcio do per\uedodo das chuvas se concentra nos primeiros 20 dias de setembro (70,5%), tendo sido observado uma equival\ueancia entre os per\uedodos secos e das chuvas em 1968, 1978 e 1997, o que implica em um maior perigo de inc\ueandios florestais.This research was developed in the Irati National Forest, located predominantly in the county of Fernandes Pinheiro, Paran\ue1 State, Brazil, using daily rainfall data from 1963 to 2006. The objective of the study was to examine the precipitation behavior, an important variable in fire occurrence, to use the information in further work on forest fire prevention and control. It was analyzed the monthly precipitation, the number of days with rain, and average daily precipitation, in terms of means, minimum and maximum values. Afterwards, the data were grouped and an analysis of the precipitation evolution for that period was carried out. It was determined and analyzed the inter annual variability of dry and rainy seasons considering the 44 years. Results showed: a) the normal fire season was concentrated from April to August, a period of lower monthly average precipitation; b) an increase in the annual precipitation along the period being studied; c) a decrease in the number of rainy days per year; and d) an increase in the daily average precipitation. It was observed an increase of 128.78 mm in the total annual precipitation, a decrease of approximately 3 days of rain, and an increase of 0.90 mm of average rainfall per day over the period. The beginning of the rain season is concentrated in the first 20 days of September (70.5%). It was observed equivalence between the dry and rain seasons in 1968, 1978 and 1997, what resulted in a forest fire danger increase