HYDROLOGICAL PROCESSESBOOK REVIEW

Hydrol. Process. 18, 393–394 (2004)Published online in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/hyp.5215

Spatial patterns in catchment hydrology—observationsand modellingRoger Grayson and Gunter Bloschl (eds)Cambridge University Press, 423 pp, 2000, ISBN 0-521-63316-8

Reviewer: Alan Hall*17 Crisp Street, Cooma NSW, 2630Australia

*Correspondence to:Alan Hall, 17 Crisp Street, CoomaNSW, 2630 Australia. E-mail:hallalan@acr.net.au

This book directly addresses the known spatial variability of catchmentbehaviour and documents the relatively few examples we have wherespatial variability has been investigated in detail in research catchments.Although a specialized book, the editors deliberately avoided filling its400 pages with detailed mathematics, instead referring the reader tothe original sources and concentrating on what inferences can be drawnfrom the observations and the models employed. The editors’ three intro-ductory chapters and summary chapter provide a good framework forthe book to examine in more detail the catchment patterns and organi-zation in precipitation and evaporation, and the resulting variations insnow (in some cases), soil moisture, groundwater and runoff. Case stud-ies include the resulting runoff from patterns of precipitation and soilmoisture in a semi-arid area, where transmission losses are an importantfactor, and spatial snow cover processes in alpine and rangelands envi-ronments, where radiation and snow drifting are respectively key factors.The use of active microwave observations greatly assists in identifyingsoil moisture patterns and can identify the saturated variable-source orsaturation-prone areas, particularly in humid areas. The development ofa Terrain Data Acquisition System enabled high-resolution soil mois-ture measurements to be made in a temperate climate catchment inan attempt to understand the spatial variability at a small catchmentscale and how this variability impacts on the hydrologic response of thelandscape. Such detailed observations enabled the effect on the spa-tial patterns of aggregating observations over different grid sizes tobe examined directly and, as in some of the other case studies, theeffects of smoothing of observations. A case study in a tropical rainfor-est examines the prediction of overland flow and the importance of thespatial variability of soil properties and the fast runoff that occurs frompipe networks. The spatial distribution of perched or shallow ground-water is shown to be significant in shallow soils, especially in humidregions. The groundwater–vadose zone interaction is found to be a crit-ical rate-limiting process governing the coupling of surface catchmentprocesses to the water table. These examples are generously illustratedby over 40 colour plates, which are necessary to give a visual displayof the spatial variability of catchment parameters and their complexity.Visual comparisons, data assimilation techniques and statistical methods

Received 31 July 2003

Copyright 2004 John Wiley & Sons, Ltd. 393 Accepted 6 November 2003

A. HALL

are discussed in covering the alternative approachesto describing catchment variability. Spatial patternsare shown to be valauble in assessing the reliabilityof distributed catchment models, as well as aiding inthe calibration of these models.

With over 540 references, this book, although spe-cialized, is most readable and will prove useful tothose seeking a general understanding of hydrologi-cal processes and, in particular, to those addressingthe issues involved in undertaking field studies ofspatial data parameters and the problems of the cal-ibration and validation of distributed models usingthese. This valuable book comes at a time when

there is a concerted effort to address the need foradequate scaling methodologies in distributed mod-els and the development of new techniques to modelcatchment behaviour in ungauged catchments wherethere is currently no hydrological information. Boththe IAHS and UNESCO have identified the need fornew theoretical developments to be supported by fieldexperiments, and for surface water hydrologists tofollow the lead of hydrometeorology with its large-scale field experiments and stochastic groundwaterhydrology in gathering spatial field data for modeldevelopment and testing. This book will assist in theseendeavours.

Copyright 2004 John Wiley & Sons, Ltd. 394 Hydrol. Process. 18, 393–394 (2004)