Funções de pedotransferência para a estimativa da retenção de água na bacia hidrográfica do Arroio do Ouro – RS, Brasil

Abstract

The understanding of soil hydric characteristics is of fundamental importance in order to comprehend the process of storage of water in the ground and its availability to plants. These properties are of slow determination and high cost, being the pedotransfer function (PTFs) an easier and more inexpensive alternative to obtaining information. The objective of this work was to generate and validate pedofunctions to the watershed of “Arroio do Ouro”. The work was done using data of water physic analysis of soil gotten through soil collection, in the 0-20 and 20-30cm layers, and from information belonging to the data bank from the Center of Study, Research and Extension HidroSedi, from Federal University of Pelotas. Totalizing 267 samples, information of texture (sand, silt and clay), density of soil, porosity (macro, micro and total), content of remaining water (Vo) and content of extracted water (V1) from the soils potentials of -1kPa, besides that, information of the content of water at potentials of -33, -100, -500 e -1500kPa were used. The variables were subjected to an interconnection test and afterwards, multiple regression analysis were made to obtain PTFs, using the option stepwise of the statistic program Systat®. The PTFs that were obtained presented a satisfactory development of the water retention curve in soils to the area of watershed of “Arroio do Ouro”.