Introducing Physical Geography

Citation

Strahler, A. H. (2013). Introducing Physical Geography (6th ed.). Wiley.

Chapter Summary

The sixth edition runs to 672 pages: an introductory chapter, seventeen numbered chapters, three appendices, a glossary and an index. Most chapters open with an "Eye on Global Change" feature on a current environmental issue, several contain a "Focus on Remote Sensing" section, and each ends with "A Look Ahead" linking it to the next. The book moves in a conventional order for the subject: tools and Earth–Sun geometry, then energy and the atmosphere, climate, the living world and soils, and finally the solid Earth and its landforms.

Introduction: Physical Geography and the Tools Geographers Use

Introduces geography and physical geography, the idea of spheres, systems and cycles, and the link between environment and global change. About half the chapter is a toolbox: maps and cartography, the Global Positioning System, geographic information systems, remote sensing and Earth visualisation tools.

Chapter 1: The Earth as a Rotating Planet

The shape and rotation of the Earth, the geographic grid, map projections, global time and the Earth's revolution around the Sun, which sets up the seasons.

Chapters 2–3: The Earth's Global Energy Balance; Air Temperature

Chapter 2 covers electromagnetic radiation, insolation over the globe, the composition of the atmosphere, energy transfer, the global energy system and net radiation by latitude, with the ozone layer as its global-change feature. Chapter 3 turns to surface and air temperature, the temperature structure of the atmosphere, daily and annual cycles, world temperature patterns, and the temperature record and global warming, opening with rising carbon dioxide.

Chapters 4–6: Atmospheric Moisture and Precipitation; Winds and Global Circulation; Weather Systems

Chapter 4 covers water in the environment, humidity, adiabatic processes, clouds and fog, precipitation types, thunderstorms, tornadoes and air quality, introduced by acid deposition. Chapter 5 deals with pressure, wind, cyclones and anticyclones, global wind and pressure patterns, winds aloft and ocean circulation, with El Niño as its feature. Chapter 6 treats air masses and fronts, midlatitude and tropical weather systems and the poleward transport of energy and moisture.

Chapter 7: Global Climates and Climate Change

The keys to climate and climate classification, followed by tours of low-, mid- and high-latitude climates (Groups I–III) and a section on climate change. Drought in the African Sahel is the opening case, and a special supplement presents the Köppen climate system alongside the book's own grouping.

Chapters 8–10: Biogeographic Processes; Global Biogeography; Global Soils

Chapter 8 covers energy and matter flow in ecosystems, ecological biogeography, succession, historical biogeography and biodiversity, opening with human impact on the carbon cycle. Chapter 9 surveys natural vegetation and the biomes (forest, savanna and grassland, desert and tundra) and climate and altitude gradients. Chapter 10 treats the nature, chemistry, moisture and development of soils and their global distribution, introduced by global change and agriculture.

Chapters 11–12: Earth Materials and Plate Tectonics; Tectonic and Volcanic Landforms

Chapter 11 covers the structure of the Earth, Earth materials and the rock cycle, global topography and plate tectonics. Chapter 12 deals with tectonic landforms, earthquakes and volcanic activity, with the 2011 Tohoku earthquake as its opening case.

Chapters 13–14: Weathering and Mass Wasting; Freshwater of the Continents

Chapter 13 covers weathering, slopes and slope processes and mass wasting, introduced by the Madison Slide. Chapter 14 follows freshwater through the hydrologic cycle: groundwater and its management, surface water and streamflow, flooding, lakes and freshwater as a resource, opening with the Aral Sea.

Chapters 15–17: Landforms Made by Running Water; Landforms Made by Waves and Wind; Glacial and Periglacial Landforms

The landform chapters close the book: fluvial erosion, transport and deposition, stream gradation and fluvial processes in arid climates; waves, tides, coastal landforms, wind action and eolian landforms; and glaciers, glacial landforms, periglacial processes and the link between global climate and glaciation, with ice sheets, sea ice and global warming as the final chapter's opening case.

Key Concepts

Introduction and Chapters 1–3: Tools, Earth–Sun Relations and Energy

• Spheres, systems and cycles: the framework the introduction uses to organise the physical environment.
• Geographic tools: maps, GPS, GIS and remote sensing, introduced early and revisited in "Focus on Remote Sensing" sections.
• Global energy balance: the budget of incoming solar and outgoing radiation, and how net radiation varies with latitude.

Chapters 4–7: Atmosphere and Climate

• Adiabatic processes: temperature change in rising and sinking air, the basis of cloud and precipitation formation.
• Global circulation: the pattern of pressure belts, winds and ocean currents that moves energy poleward.
• Climate classification: grouping climates by latitude and by temperature and precipitation regimes, with the Köppen system as a supplement.

Chapters 8–10: Biosphere and Soils

• Ecosystem energy and matter flow: how energy and nutrients move through living systems.
• Biomes: the major vegetation formations and their relation to climate and altitude.
• Soil development: how soils form and how their chemistry and moisture vary across the globe.

Chapters 11–17: Solid Earth and Landforms

• Plate tectonics: the movement of lithospheric plates that creates major relief features, earthquakes and volcanoes.
• Mass wasting: downslope movement of weathered material under gravity.
• Hydrologic cycle: the movement of water through atmosphere, surface and groundwater.
• Fluvial, coastal, eolian and glacial landforms: landscapes shaped by running water, waves, wind and ice.

Critical Analysis

Strengths

• Written for non-science readers. Wiley describes the book as helping non-science readers to visualise and understand Earth processes and to learn the basic language of physical geography, and highlights its clear writing and distinctive photographs and illustrations. Its "Visualization" theme and "Putting You in the Picture" features are designed for that audience.
• Global change built in. An "Eye on Global Change" case opens most chapters, from the ozone layer and rising carbon dioxide to El Niño, Sahel drought, the Aral Sea and polar ice, so environmental change is part of every topic rather than a final chapter. The sixth edition updated the climate-change data and strengthened this coverage.
• Tools taught early. The introduction gives the geographer's toolbox (cartography, GPS, GIS, remote sensing) a full section, and remote sensing returns in many chapters, reflecting the author's research background in remote sensing of vegetation.
• Broad coverage. By the page numbers in the contents, about 200 pages go to energy, atmosphere and climate, about 110 to biogeography and soils, and about 215 to the solid Earth and landforms, so the book can support courses with different emphases. A glossary, appendices on climate definitions, conversion factors and topographic map symbols, and an instructor and student companion site come with it.

Limitations

• Dated edition. The sixth edition appeared in 2013, and its climate data and examples date from that time; the latest global-change material will need updating from current sources.
• Descriptive rather than quantitative. The publisher frames it for non-science readers; students who want the physics of radiation and circulation will need a more quantitative text.
• Long for one term. At 672 pages with eighteen chapters, a one-semester course must select, especially among the landform chapters.

Where It Fits in the Course

Strahler is the standard-length survey textbook for this course. Jeremy Patrich's Physical Geography is a free open textbook that is shorter and weighted towards geology and landforms, with no unit on the biosphere; Strahler covers the same ground and adds full chapters on climate regions, biogeography, biomes and soils, so the two pair well when cost or length matters. Christopherson and Birkeland's Geosystems is a comparable systems-based survey organised around atmosphere, hydrosphere, lithosphere and biosphere; a course normally chooses one of the two.

Smithson, Addison and Atkinson's Fundamentals of the Physical Environment explains the processes behind climate, landforms, soils and ecosystems in more depth and is a natural second-year follow-up. Hartmann's Global Physical Climatology treats in quantitative form the energy balance and circulation that Chapters 2–6 describe qualitatively, and suits students moving towards climate science.

How to Use This Book

The book suits first-year students, including those without a science background; secondary-school science is enough. A practical plan for a one-semester course:

• Core: the Introduction and Chapters 1–7 (tools, Earth–Sun relations, energy, atmosphere, weather and climate), then Chapter 11 on plate tectonics and Chapters 13–15 on weathering, freshwater and running water.
• By course emphasis: Chapters 8–10 for courses that include biogeography and soils; Chapters 12, 16 and 17 for courses that stress landforms.
• Use the features actively. Read each "Eye on Global Change" case as a short reading on its own and look up what has happened since 2013. Treat "A Look Ahead" as the bridge to the next chapter.
• Practise with the tools. Pair the introduction's toolbox section and the "Focus on Remote Sensing" sections with free online maps and satellite imagery, and use Appendix 3 when reading topographic maps.

Use the glossary while reading, and the Köppen supplement after Chapter 7 if the course uses that system.