Review of Hydrology: An Introduction by Wilfried Brutsaert: Cambridge University Press, Cambridge, U.K., 2005.

As stated by the author, the goal of this book is “to present a coherent introduction to some of the concepts and relationships needed to describe the distribution and transport of water in the natural environment.” The book admirably accomplishes this goal through the wealth of information contained in 14 chapters and one appendix. Chapter 1 furnishes an excellent introduction to hydrology; the remaining chapters are divided into four parts: Part I covers water in the atmosphere, Part II covers water on the surface, Part III covers water below the surface, and Part IV covers flows at the catchment scale in response to precipitation. After beginning with the definition and scope of hydrology, Chapter 1 discusses the hydrologic cycle, the global water balance, methodologies, and procedures and conservation laws. The discussion is lucid and informative. Since this chapter is introductory, it would have been desirable to provide a broader discussion of hydrology—including water quality, erosion and sedimentation, land use effects, snow and glaciers, ecosystems, design considerations, and measurements—and then limit the scope to what is treated in the book.

Part I—on water in the atmosphere—includes three chapters. Chapter 2 succinctly presents elements of fluid mechanics of the lower atmosphere—including water vapor, atmospheric stability, turbulent transport, atmospheric boundary layer, turbulence similarity, and energy budget constraints. The discussion is excellent and is much better than what is presented in most hydrology textbooks. Chapter 3 discusses precipitation. It begins with a discussion of the formation of precipitation, including cooling of the air, moisture supply, water recycling, and types of precipitation. The chapter then discusses major precipitation weather systems—including extratropical cyclones and fronts, extratropical convective weather systems, seasonal tropical systems, large-scale tropical convective systems, and orographic effects; precipitation distribution on the ground, including spatial distribution, temporal distribution, and runoff design rainfall data; and interception, including interception loss mechanisms, vegetation structural parameters, and empirical equations. The chapter concludes with a discussion of operational precipitation measurements. This chapter is excellent and comprehensive. Chapter 4 deals with evaporation. It discusses evaporation mechanisms, mass transfer formulations, energy budget and related formulations, water budget methods, and evaporation climatology. The entire discussion is detailed and well illustrated with graphs and tables. Part I of the book stands out, especially when compared with other hydrology textbooks. It is rich in information, and the discussion is very appealing.

Part II—about water on the surface—consists of three chapters. Water on the land surface constitutes the subject of Chapter 5. It discusses free surface flow, shallow-water wave equations, friction slope, and features of free surface flow. Overland flow is presented in Chapter 6. Included are the standard formulation, kinematic wave approach, and lumped kinematic wave approach. It does not include any treatment of infiltrating flow. Chapter 7 treats streamflow routing. Beginning with a discussion of two extreme cases of large flood wave propagation, including surge or dynamic shock and monoclinal rising wave or kinematic shock, it presents the Muskingum method. It does not treat flow in channel networks and flow routing in abstracting channels. On the whole, Part II is comprehensive and is an excellent treatment of flow over the land surface.

Part III—about water below the surface—contains three chapters. Water beneath the ground is presented in Chapter 8, which discusses porous materials, hydrostatics of pore-filling water in the presence of air, water transport in a porous material, and field equations of mass and momentum conservation. Chapter 9 presents infiltration and related unsaturated flows. Included are general features of the infiltration phenomenon, infiltration capacity in the absence of gravity, infiltration capacity, rain infiltration, catchment-scale infiltration and other losses, and capillary rise and evaporation at the soil surface. Groundwater outflow and baseflow are discussed in Chapter 10. Beginning with a discussion of flow in an unconfined riparian aquifer, it treats four approximations of groundwater flow, including free surface flow (the first approximation), hydraulic groundwater theory (the second approximation), linearized hydraulic groundwater theory (the third approximation), and kinematic wave in sloping aquifers (the fourth approximation); and catchment-scale base flow parameterizations. Part III presents a comprehensive and thorough discussion of flow below the surface.

Part IV, about flows at the catchment scale in response to precipitation, includes four chapters. Streamflow generation is the subject of Chapter 11. Included are riparian areas and headwater basins, storm runoff mechanisms in riparian areas, and a summary of mechanisms and parameterizations. Chapter 12 deals with streamflow response at the catchment scale. The chapter discusses the unit hydrograph, identification of linear response functions, stationary and nonlinear lumped response, and nonstationary linear response. Elements of frequency analysis in hydrology are treated in Chapter 13, which discusses random variables and probability, descriptors of a probability distribution function, probability distributions for discrete variables, probability distributions for continuous variables, and extension of available records. Chapter 14 is a concluding chapter and presents a short historical sketch of theories about the water circulation on earth. Starting with a discussion of the earliest concepts of the atmospheric water cycle, it then discusses Greek antiquity, the Latin era, and the transition from philosophy to science by experimentation. Myths, beliefs, and concepts held even today in Asian countries are not well represented. On the whole, this part is well covered.

The book is well written, topics are well organized, the prose is easy to read and understand, the style is lucid, and the book includes a wealth of information—reflecting the author’s vast knowledge and experience. The intended audience is the senior undergraduate engineering student or beginning graduate student. For a student in hydrology, it should be compulsory reading. Except for Chapter 13, the book represents a deterministic treatment. Teachers and researchers in hydrologic science and engineering will find the book extremely useful and enlightening.