Haie, Naim

Irrigation and Drainage

Universidade do Minho: RepositoriUM

COMMENT: EFFICIENT IRRIGATION; INEFFICIENT COMMUNICATION;FLAWED RECOMMENDATIONSC. PERRY (2007) IRRIGATION AND DRAINAGE 56: 367–378N. HAIE*Water Resources and Environment Group, Civil Engineering Department, University of Minho, Campus of Azurem, Guimara˜es, Portugal1. OBJECTIVESIt seems that the paper (essentially an irrigation paper) has the following basic objectives:a) Evidence based demonstration of the inadequacy of efﬁciency to promote ﬂawless recommendations and, assuch, the need to abandon ‘‘efﬁciency’’ altogether.b) Conceptual based demonstration of ‘‘fractions’’ and their adoption by ICID for further use.2. STRUCTUREThe general structure of the paper does not focus on the objectives mentioned above. For example one sectionentitled ‘‘The Irrigation Approach to Accounting’’ deals with a vast array of issues such as: Classical Efﬁciency(CE, also irrigation efﬁciency), Effective Efﬁciency (EE), basin efﬁciency, water saving, fractions, EuropeanWaterFramework Directive (WFD), water productivity, evidences, etc. Consequently, the treatment of these issues iscursory at best. A few of these points are discussed below:A. The paper puts CE into spotlight by making it clear through various evidences that it does not work and givesﬂawed recommendations. This is indeed true (for a formal rejection of CE, both through equations andthrough examples, one can refer to the upcoming paper by Haie and Keller). However because of the fallacyof one type of efﬁciency, the paper is making a generalization for all types of efﬁciencies. Also, except forCE, the paper does not make the deﬁnition of the efﬁciencies clear, such as ‘‘basin efﬁciency’’ or theefﬁciency that ‘‘frequently exceeds 100%’’. It is generally assumed that the evidences put forth by the paperas problematic have indeed used CE.B. The paper mentions two weaknesses about EE but without any evidence, contrary to the objective of thepaper. These are:a) ‘‘nature of the pollutant’’: since this is an irrigation paper and salt is a major quality problem, EE is wellposed to solve it with the current knowledge (as acknowledged by the paper). This by itself, and the factthat EE includes in its formulation irrigation return ﬂow, makes this type of efﬁciency an indicator thatpromotes sustainability and worthy of serious consideration.For a combination of quality problems, an index (such as chemical status in WFD, water quality indexin Kaurish and Younos, 2007, etc.) should be used for EE calculations.On the other hand, if quality is to be analyzed separately, a point that the paper insists, a quantity onlyversion of EE (Haie and Keller) that includes return ﬂow will solve all the problems brought about in theIRRIGATION AND DRAINAGEIrrig. and Drain. 57: 245–247 (2008)Published online in Wiley InterScience (www.interscience.wiley.com) DOI: 10.1002/ird.422*Correspondence to: N. Haie, Water Resources and Environment Group, Civil Engineering Department, University of Minho, Campus ofAzurem, 4800-058 Guimara˜es, Portugal. E-mail: naim@civil.uminho.ptCopyright # 2008 John Wiley & Sons, Ltd.paper as evidences for rejecting efﬁciency. Including recycled water, as mentioned above, is one of theadvantages of EE over the problematic CE.Finally it should be noted that even if one uses fractions - valid and important in various analysis - nomanagement decision can be made without somehow integrating quality and fractions (quantity). Howthis gets done in order to promote ﬂawless recommendations is not clear from the paper. So comparing anindex such as EE to fractions seems not justiﬁed.b) ‘‘nature of the downstream use’’: This issue is also important whether one uses fractions or efﬁcienciesand should not be mentioned as an exclusive weakness of one or the other. However, as mentioned before,EE incorporates reused water and can correctly explain the impact of interventions on the downstreamusers - a rather important aspect of EE in relation to say CE.C. WFD is a European wide policy for water adopted in a process of co-decision by both the European Union(EU) Parliament and the Council. The paper should have mentioned that the provision of improvingefﬁciencies referred to in that policy is coupled with securing sustainability, for example it states that‘‘measures to promote an efﬁcient and sustainable water use in order to avoid compromising the achievementof the [environmental] objectives’’ should be adopted. So the real and practical question is how to develop asustainable and efﬁcient water system rather than simply rejecting the whole idea of efﬁciency.3. EVIDENCESA. Some of the evidences mentioned in the paper (for example on page 373) do not have references and hence itis not possible to verify the validity of their conclusions. This is rather important, particularly for an evidencebased paper. Note number 4 about WFD and efﬁciencies is not relevant: not only does it not have a date butmore importantly it is a personal view of an individual about an institutional policy (please also see 2Cabove).B. The ﬁrst evidence explained is the example given by Peter Gleick. We are familiar with this example and donot agreewith the following statement of the paper: ‘‘However, claims implying the most obvious ‘‘saving’’ –of physical, wet, useful water – are misleading, indeed wrong.’’ The example was referring (as mentioned inthe paper) to a type of saving which can be designated as ‘‘diversion saving’’ (other type being ‘‘depletionsaving’’ – more in Haie and Keller). Consequently, this particular evidence of Peter Gleick gave a properrecommendation (diversion saving).C. Finally, in order to formally demonstrate through evidence that the use of efﬁciency brings about ‘‘InefﬁcientCommunication’’ and ‘‘Flawed Recommendations’’, one needs to develop a sample population of evidences,make a hypothesis and test its signiﬁcance by an appropriate statistical test. This, of course, was not done inthe paper, and although the conclusions taken by Chris Perry are correct as to the validity of the use ofhydrological fractions, we feel that the paper should not form the basis for ICID rejection of all types ofefﬁciency.4. TERMINOLOGYA. Although the terms ‘‘adopted’’ in the ‘‘Conclusions and Recommendations’’ section of the paper areindividually valid and useful, they may not add to clariﬁcations sought by the paper. In other words, there isno methodology recommended for the use of the fractions, nor are examples set forth to clarify their practicalusage. Consequently, one can easily fall into the same trap that the paper is trying to unravel. For example,one can use the ‘‘Beneﬁcial Consumption Fraction’’ which is ‘‘Beneﬁcial consumption’’ deﬁned in item‘‘3.b.i’’ divided by Withdrawal, item ‘‘2’’. However the use of this fraction under the disguise of newterminology is as harmful as before since it is actually CE, which the paper is trying to reject. It should also benoted that this fraction is value-laden (Molden and Sakthivadivel, 1999) contrary to the implications of thepaper.Copyright # 2008 John Wiley & Sons, Ltd. Irrig. and Drain. 57: 245–247 (2008)DOI: 10.1002/ird246 N. HAIEB. The paper proposes a framework that is the totality of the fractions themselves, i.e., items 2 and 3 of theConclusions section. It tries to give validity to this framework by stating that ‘‘it meets the criterion ofcontinuity of mass.’’ However, this should be completed by including other sources of water besidesWithdrawal that enter the system of analysis and have to be considered to satisfy mass continuity. Besides,the fractions themselves may be partially deﬁned, for example, a ‘‘beneﬁcial consumption’’ has been deﬁnedas ‘‘Water evaporated or transpired for the intended purpose’’. However, it can also include those that are notpart of the ‘‘intended purpose’’ (Molden and Sakthivadivel, 1999).C. ‘‘Withdrawal’’ as one of the ‘‘water use’’ types provokes ‘‘change in storage’’ (item 3.a) of the source ofwater. Part of it can become ‘‘recoverable fraction’’ and goes back to the source and makes a ‘‘change instorage’’. This is a rather typical situation which causes quality degradation of the ‘‘storage’’. However thepaper in its conclusions mentions that ‘‘The key characteristic of storage is that thewater entering and leavingis essentially of the same quality.’’ACKNOWLEDGEMENTSThe author would like to express appreciation for review of these comments by Dr. Andrew A. Keller and Dr. DavidSeckler.REFERENCESHaie N, Keller AA. Effective efﬁciency as a tool for sustainable water resources management. Journal of the American Water ResourcesAssociation (in press).Kaurish FW, Younos T. 2007. Developing a standardized water quality index for evaluating surface water quality. Journal of the American WaterResources Association (JAWRA) 43(2): 533–545.Molden D, Sakthivadivel R. 1999. Water accounting to assess use and productivity of water. International Journal of Water ResourcesDevelopment 15(1): 55–71.Copyright # 2008 John Wiley & Sons, Ltd. Irrig. and Drain. 57: 245–247 (2008)DOI: 10.1002/irdCOMMENT 247

Comment: Efficient irrigation; inefficient communication; flawed recommendations

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Comment: Efficient irrigation; inefficient communication; flawed recommendations

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