文档介绍：Table of ContentsCrop evapotranspiration - Guidelines puting crop water requirements - FAO Irrigation and drainage paper 56Table of ContentsbyRichard G. AllenUtah State UniversityLogan, Utah, USA Luis S. PereiraInstituto Superior de AgronomiaLisbon, Portugal Dirk RaesKatholieke Universiteit LeuvenLeuven, Belgium Martin SmithWater Resources, Development and Management ServiceFAO FAO - Food and anization of the United rep/X0490E/ (1 sur 11) [19/03/2003 14:28:12]Table of ContentsNationsRome, 1998The designations employed and the presentation of material in this publication do not imply the expression of any opinion whatsoever on the part of the Food and anization of the United Nations concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or -56ISBN 92-5-104219-5 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying or otherwise. without the prior permission of the copyright owner. Applications for such permission, with a statement of the purpose and extent of the reproduction, should be addressed to the Director, Information Division, Food and anization of the United Nations, Viale delle Terme di Caracalla, 00100 Rome, Italy. ? FAO 1998This electronic document has been scanned using optical character recognition (OCR) software and careful manual recorrection. Even if the quality of digitalisation is high, the FAO declines all responsibility for any discrepancies that may exist between the present document and its original printed of ContentsPrefacerep/X0490E/ (2 sur 11) [19/03/2003 14:28:12]Table of ContentsAcknowledgementsList of principal symbols and acronymsChapter 1 - Introduction to evapotranspirationEvapotranspiration processEvaporationTranspirationEvapotranspiration (ET)UnitsFactors affecting evapotranspira