Análise espacial das variáveis hidrológicas, precipitação e balanço hídrico, como subsídio para o planejamento ambiental da bacia do Rio Pirapó-PR

Abstract

The objective of this study was to study and spatialize the hydrologic variables rainfall and water balance, in order generate information that indicate areas with skills and fragile environmental and helping the environmental planning Pirapó River Basin, which covers 33 municipalities with nearly one million inhabitants and is located on the third plateau of Parana. Have been used monthly rainfall data, obtained from the Hydrological Information System of the Water Institute of Paraná of 8 pluviometric stations the period 1976 to 2010. The monthly data of air temperature were acquired at weather stations in Maringá, Paranavaí and Apucarana. Later was carried out the application of descriptive statistics using the parameters, mean, standard deviation and coefficient of variation for the scales of analysis monthly, quarterly, seasonal and annual basis. For the spatial distribution of rainfall was elaborated by software Surfer 10.0 isohyetal letters with the outline of the study area and the average rainfall data for the respective scales of analysis. To calculate the water balance, was used the Thornthwaite and Mather (1955) method, using the program developed by Sentelhas et al. (1999) that, besides the data of temperature and precipitation, also considers the degrees, minutes and seconds of latitude and longitude and altitude of the desired point. The water balance was calculated only for some years as atypical, or dried or wet, according to the method of Monteiro (1976), applied to the choice of "standard year". The spatial distribution of rainfall showed a gradual decrease in the amount towards the downstream basin. The spatial and temporal variability of rainfall distribution on scales monthly, seasonal and annual, is strongly evident with the spatial distribution of rainfall data. The calculation and spatialization of the water balance showed that to the region north of the basin, for all the years analyzed, presented greater of water deficit, and longer periods of water scarcity in the soil, thus becoming the region with the highest probability deficit soil water. The spatialization and analyze of water balance and rainfall for the basin of the river Pirapó generated data and satisfactory results for a better understanding of the dynamics of hydrological phenomenon in the study area, these should be the basis for further studies that will discuss the best plan of impactant activities to the environment to be guaranteed the economic development as well as environmental preservation.