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flow is considered to be approximated by a sequence of steady-state situations. The author validates his model in a s tudy of soil-water and groundwater behaviour in a s tudy area in The Netherlands. Useful sensitivity analyses are given to indicate the effect of varying the physical parameters in the model.

The book will interest those using similar modelling techniques in soil- water movement studies. However, readers may consider that the work could have been reported more usefully in a briefer form in a scientific journal rather than in book form.

E.G. YOUNGS (Harpenden, Great Britain)

SALINITY IN IRRIGATION AND WATER RESOURCES

Salinity in Irrigation and Water Resources. Dan Yaron (Editor). Marcel Dekker, New York, 1981. vii + 432 pp., CHF 160/US$80.00, ISBN 0-8247- 6741-1.

This compendium of papers on salinity, Number 4 in the Series Civil Engineering, deals with an important subject in a disappointing way. With each chapter wri t ten by different authors, the editor quite appropriately made an a t tempt to provide a broad, multi<lisciplinary overview of many of the aspects involved in the subject. There are chapters on chemistry and physics, on physiology and engineering, on economics and law, on planning and social science. Perhaps it is this broad coverage that contr ibuted to the disappoint- ment this reviewer experienced: the book lacks focus.

Some chapters -- or parts of chapters -- are very elementary and very general, while others pack in substantial detail; often, however, this detailed t reatment is not developed very satisfactorily. Some deal with a topic clearly appropriate to the subject, such as Bernstein's crop tolerance to salt; others are only vaguely related, as Heady and coworkers ' discussion of modelling soil conservation practices to enhance erosion control. Thus, the question arises: What is the intended readership?

The book also is rather badly dated. Even though it shows a publication date of 1981, the latest citation noted was 1975 and much of the text reflects a lag of at least 5 years be tween writing and publishing. Editorial standards were not particularly high. Misprints are common; some authors use appended citation lists, others footnotes .

Dan Yaron's opening chapter a t tempts to establish a systems framework for assessment of the salinity problem in irrigation and then proceeds with a brief commentary on each following chapter within this framework. This int roduct ion is fol lowed by B.L. McNeal's discussion of water quality. Al- though it offers a useful introduct ion to the subject, it suffers several short-

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comings. It perpetrates the conversion from TDS to EC by 640 without adequate hedges; it places unfortunate emphasis on pHc, a concept that prob- ably has outlived its usefulness and should be permitted to rest in peace.

L. Bernstein's lucidly written chapter on crop tolerance has no new infor- mation or interpretation, other than an ingenious a t tempt to demonstrate the interrelation of irrigation frequency and water quality. E. Bresler provides a very competent t reatment of water and solute transport through soils. This chapter seems technically more detailed than the others, and possibly a bit too detailed. This is especially apparent when some of the material is not adequately explained or connected; for example, his fig. 8 is neither self- contained nor properly explained in the text. The chapter by J.J. Jurinak and R.J. Wagenet deals with a subject -- fertility--salinity interactions -- about which little of interest can be written. It shows: the primary conclusion of the chapter is that, other than the obvious increase in osmotic pressure of the soil solution from the addition of fertilizer, few significant generalizations can be made.

G.V. Skogerboe and W.R. Walker present a very general description of the many components entering into a total irrigation water management project or system, emphasizing the need for "management" as well as "development" and stressing the need for water use efficiency in relation to its effect on downstream water quality. They then describe in considerable detail a part of their approach to modelling and illustrate their use of such models with an example of the cost effectiveness of canal lining. The chapter's title " Impact of Irrigation on the Quality of Groundwater and River Flows" leads the reader to expect quite a different t reatment from that actually encountered.

Here the book shifts direction and chapters 7 to 12 deal with economic subjects. C.V. Moore addresses the impact of an increase in the salinity of the irrigation water in Imperial Valley, California. He outlines an analytical procedure that uses a crop yield response function with water quanti ty and quality as independent variables and then uses linear programming techniques to optimize return to land and water. R.J. Hanks and J.C. Andersen combine extensive field data, a physical model and an economic model to evaluate the consequences of techniques to reduce the amount of salt in irrigation return flows. They effectively illustrate some of the policy questions that must be resolved -- e.g., who pays? -- but unfortunately the specifics of their analysis cannot be accepted for extrapolation. The water contributed to the crop from groundwater in the field data and the relative rooting depths and root sink functions assumed severely limit the value of the conclusions.

R.A. Young and K.L. Leathers assess the economic impacts of several alter- native strategies for reducing salt in return flow from the Grand Valley in Colorado. They conclude that only on-farm measures to improve water manage- ment are justified, and those only on the assumption that farmers wish to implement such measures voluntarily. Costs of enforcing mandatory controls and of off-farm measures are thought excessive. The question of equity -- who pays, who benefits? -- is raised again.

2 7 9

C.W. Howe and J.T. Young expand the area of consideration to the whole Colorado River Basin and estimate the changes in regional income expected from agricultural damages imposed by salinity. They also estimate the costs of various control measures to reduce the salt loading of the river and then compare such costs with expected benefits.

The last five chapters mentioned have all dealt with aspects of the Colorado River, an indication of its dominance in salinity considerations in the U.S.A. The next chapter, however, not only leaves the River; it leaves salinity and irrigation as well. E.O. Heady, K.J. Nicol and J.C. Wade consider elaborate models, sometimes including 10,000 equations and 150,000 variables, that have been used for assessing the economic implications for the U.S.A. as a whole of measures to reduce erosion (and thus, non-point pollution). The authors do present some interesting results, such as the expected increase in farm prices needed to achieve prescribed levels of control.

G. Fishelson and G.S. Tolley,write on cost sharing and pricing for water quality. Not an economist , this reviewer may have missed the point. However, he failed to find any relevance in this chapter to the question of water pricing and salinity control cost sharing in agriculture. The conclusion reached, that society should not be concerned with income redistribution consequences of water quality policies, but only with economic efficiency, was not per- suasive.

R.W. Johnson, under the heading of Legal and institutional approaches to salinity management, gives a readable account of the history of laws and agreements concerning the Colorado River. He notes, surprisingly, that water use regulations have not been tested as legal tools and would probably fail. He notes correctly, bu t with misleading connotat ions, that a decision was made for the Government to purchase 4000 ha (10,000 acres) of authorized irrigable land in the Wellton-Mohawk District of Arizona; he fails to mention that, wi thout that purchase, this land could not be irrigated because of the lack of sufficient water rights -- thus the purchase was an inducement to, not a concession from, the District and its landowners.

A chapter on desalting by N. Arad and P. Glueckstern, has as its main message that desalting is not for agriculture. Cost estimates per m 3 (1975!) of $0.35 to $0.54 for brackish water RO and $0.97 to $1.57 for distillation compare with value for irrigation of $0.01 or $0.02. The description of the various processes (reverse osmosis, electrodialysis, distillation), their thermo- dynamic efficiencies and actual performance, is of general interest to the nonspecialist.

Chapter 15, by A. Wiener, concerns a strategy for water resources manage- ment. He uses a jargon -- phase space, decision space -- that makes the mes- sage less palatable and unnecessarily obtuse. He makes the important , if obvious, observation that water resource management is indispensable in arid regions and more needed every day in humid regions. His proposal to extend the planning horizon to take account of the interests of future generations is laudable, but probably utopian.

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A.V. Kneese and J.E. Zamora close the book with a philosphical and fairly pessimistic discussion of the future of arid lands. Noting that in arid lands is found the cradle of civilization, they express the hope that such a cultural blossoming is possible again in the future. However, they note that today arid lands tend to have a disproportionate share of poverty, as measured by per capita income; their development faces greater difficulties than climatic- ally more blessed regions.

In a book as diverse as this one, one may expect to encounter conflicting as well as mutually supporting viewpoints. Such contrasts are indeed present; they are healthy and add some spice to the package. For example, Kneese and Zamora estimate the cost of desalting as $0.06 per m 3 and judge that too high for irrigation; the experts ' cost estimate is much higher, but they appear enthusiastic about its potential uses. Skogerboe and Walker advocate an in- f low--outf low analysis to check for salt balance, while McNeal counsels caution, pointing out some of the pitfalls in the concept.

JAN VAN SCHILFGAARDE

(Riverside, CA, U.S.A.)

SALINE IRRIGATION WATERS - - A N N O T A T E D BIBLIOGRAPHY 1950--1980

International Research on Saline Irrigation Waters - -an Annota ted Biblio- graphy 1950--1980. I.C. Gupta and K.N. Pahwa. Agricole Publishing Academy, D-76 Panchsheel Enclave, New Delhi- l10017, India, 1981. xiii + 389 pp., India-Rs. 170,00/US$ 34.00.

The authors have gathered into 394 pages about 900 references to original articles in scientific journals, some few books and official reports. Each individual reference is annotated to give a precis of its contents, either from the authors ' own reading of it, or more rarely from the original author 's summary. There are 9 books referenced, of which 5 are of Indian origin and 23 proceedings of symposia. Most of the 900 articles referred to have been drawn from more than 240 journals, which therefore supply the sources, at about 3 or 4 papers per journal, on the average.

The best known journals for soil science provide numerous entries. For example, the Soil Science Society of America Journal, and its predecessor, the Proceedings, affords 27, Soil Science (Baltimore) 29, Pochvovedenie 12. There are some mistakes, including the amusing Queensland Journal of Agronomy, University of Palermo, Australia, which is entered in the Source Index for one reference. (It really is Palermo and the authors are Italians). The Journal of the Indian Society of Soil Science appears to provide the most numerous sources with 53, then followed by the Indian Journal of Agricul- tural Science with 44.