• JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  Bookmark and Share
Master's Dissertation
Full name
Roberto Rezende
Knowledge Area
Date of Defense
Piracicaba, 1992
Title in Portuguese
Desempenho de um sistema de irrigação pivô-central quanto a uniformidade e eficiência de aplicação de agua, abaixo e acima da superfície do solo
Keywords in Portuguese
Abstract in Portuguese
Este trabalho teve como objetivo avaliar as características de desempenho do equipamento de irrigação pivô central operando em condições de campo e também analisar o comportamento da agua abaixo da superfície do solo quanto a uniformidade de distribuição. Para tanto utilizaram-se os coeficientes de uniformidade de Christiansen e de distribuição calculados conforme metodologia proposta por MERRIAN e alii (1973) e também com dados de umidades do perfil de solo em três profundidades. O pivô foi ensaiado em três velocidades 20, 40 e 60% com a linha lateral em duas posições sendo uma em nível e a outra em aclive. Os resultados obtidos mostram que em todas as profundidades os coeficientes de uniformidade foram superiores aos obtidos acima da superfície os valores dos coeficientes de uniformidade aumentaram com o tempo em todas as profundidades, os altos valores alcançados pelos coeficientes de uniformidade abaixo da superfície do solo mostraram que a uniformidade subsuperficial pouco depende da uniformidade acima da superfície
Title in English
Performance of center pivot irrigation system about uniformity and eficience water aplication over and down ground surface
Abstract in English
The objective of this research was to evaluate the performance characteristics of a center pivot irrigation equipment operating at field conditions and analyze the under the surface of the soil water behavior in regard to its distribution uniformity. The performance of the system was evaluated by Christiansen uniformity coefficient (CUC) and the coefficient of uniform distribution (CUD). Both were calculated from precipitation data collected according to the method of MERRIAN et alii (1973) as well as with moisture data from the layer of the soil at three depths. The experiments were conducted on the campus of Universidade Estadual de Maringá. Paraná, in a Red Earth (Paleudult) type of soil. The center pivot was tested at 20%,40% and 60% velocities with the lateral line at level and 5,78% upward. The equipment of irrigation operated with all emissaries opened and with ten of them clased in order to obtain high and low values of coefficient of uniformity. Those values were compared to those from the under the surface of the soil. The results of this research all owed the following conclusions: the Application Potencial Efficiency reduced with the increase of the ambient temperature and the reduction of the air reIative humidity; - the coefficients of uniformity were always greater for conditions under the surface of the soil than for conditions above it; -the under the surface of the soil coefficients of uniformity increased with time, at all depths investigated; - the high values obtained by the under the surface of the soil coefficients of uniformity in short periods of time, even in those tests where the uniformity of the water supplied to the surface was low, indicate that the uniformity under the surface of the soil is almost independent of the above, the surface of the soil uniformity
WARNING - Viewing this document is conditioned on your acceptance of the following terms of use:
This document is only for private use for research and teaching activities. Reproduction for commercial use is forbidden. This rights cover the whole data about this document as well as its contents. Any uses or copies of this document in whole or in part must include the author's name.
RezendeRoberto.pdf (4.32 Mbytes)
Publishing Date
WARNING: Learn what derived works are clicking here.
All rights of the thesis/dissertation are from the authors
Digital Library of Theses and Dissertations of USP. Copyright © 2001-2022. All rights reserved.