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Áreas de influência das estações pluviométricas na bacia rio do Peixe/SC pelo método de polígonos de Thiessen utilizando imagem de satélite e SIG
Karla Gomig1
Elfride Anrain Lindner1
Masato Kobiyama2
1
Universidade do Oeste de Santa Catarina - UNOESC
Rua Getúlio Vargas, 2125 - 89600-000 - Joaçaba - SC, Brasil eng.karla@yahoo.com.br; elfride.lindner@unoesc.edu.br
2
Universidade Federal de Santa Catarina – UFSC
Centro Tecnológico (CTC) – Campus Universitário – Trindade
88010-970 – Florianópolis – SC, Brasil kobiyama@ens.ufsc.br Abstract. The paper focuses on weight estimation employing internal ArcView routines to calculate areas and weight factors. The ArcView GIS, extension “Create Thiessen Polygons” was used to localize rainfall stations with areas of influence in the Peixe/SC river watershed which is a Uruguay river tributary. The total drainage area was divided into four sub-watersheds, regarding to the gauge stations of Rio das Antas (801 km2), Tangará
(2,017 km2), Joaçaba (3,721 km2) and Piratuba (5,238 km2). Nineteen rainfall stations have their own influence areas, aiming the mean precipitation calculation over the sub-watersheds. Considering the total area and year
2002 further the stations present weight of 13,68% (Salto Veloso); 12,34% (Caçador); 11,11% (Joaçaba);
10,29% (Videira); 8,88% (Macieira) and 7,29% (Campos Novos). The other thirteen stations compliment the remaining 36,4% of Peixe/SC watershed. Applying GIS is less time-consuming and easier for Thiessen polygons method application when mean precipitation over an area is calculated.
Palavras-chave: Thiessen polygons, watershed, mean precipitation; polígonos de Thiessen, bacia hidrográfica, precipitação média.
1. Introdução
A precipitação varia temporal e espacialmente. O conhecimento da distribuição e variação da precipitação, tanto no tempo como no espaço, é