Geomorphic responses to climatic change. William B. Bull, 1991, Oxford University Press, xviii + 326 pp., $59.95 (clothbound)
✍ Scribed by Michael D. Blum
- Book ID
- 102225982
- Publisher
- John Wiley and Sons
- Year
- 1993
- Tongue
- English
- Weight
- 240 KB
- Volume
- 8
- Category
- Article
- ISSN
- 0883-6353
No coin nor oath required. For personal study only.
✦ Synopsis
Geomorphic Responses to Climatic Change by W. B. Bull uses a selected set of detailed case studies as a vehicle to examine responses of fluvial systems to Late Quaternary climatic change. It was designed to attract a readership consisting of advanced students and professionals in geomorphology and allied fields, and perhaps for use as a text in advanced geomorphology courses. The author notes this is the first of two volumes, with the second devoted to fluvial response to active tectonics.
Contents of the book can be subdivided into three parts. Chapter 1 provides an overview of some of the major concepts in fluvial geomorphology; for example, base level of erosion, equilibrium states, geomorphic thresholds, response and relaxation times, the relationship between stream power and resisting power, and the importance of spatial and temporal scale. In doing so, this chapter draws on some of the standard geomorphological literature, as well as the author's own conceptual model, where fluvial response to changes in external controls can be understood in terms of the threshold of critical power. This is a slightly modified version of older conceptual models that discussed aggradational and degradational responses to changes in the relationship between sediment transport efficiency and sediment load. The chapter closes by discussing genetic types of stream terraces, where an important distinction is made between the spatial and temporal scale of allocyclic climatic and tectonic terraces as compared to those produced as a consequence of autocyclic complex response mechanisms.
Chapters 2-5 constitute the main body of this volume, and present a series of detailed case studies performed for the most part by the author, former students, and colleagues. Each case study is drawn from different climatic and geologic settings, ranging from relatively simple to very complex, where sufficient field work, laboratory analyses, and chronological controls permit development of an integrated story. Chapter 2 is focused on small desert streams draining tectonically inactive, monolithologic terrains in the southwestern United States, but also includes some discussion of the history of the lower Colorado River (western United States), and the role it plays as a regional base level for smaller tributaries. Chapter 3 begins by discussing lithologic controls on hillslopes and fluvial response to climatic change in the hot deserts of Israel and western Sinai, and ends with a more general discussion of these concepts that incorporates examples from northern Mexico and the southwestern United States. Chapter 4 is again set in the American West, examining small streams in the tectonically active, high altitude San Gabriel Mountains of Southern California. And finally, Chapter 5 addresses the Charwell River in New Zealand, within an overall humid-temperate climatic setting, but where vertical zonation of climate and vegetation is strongly pronounced, and where tectonic activity is very important. Each chapter proceeds by outlining geologic and climatic controls, paleoclimatological data, Quaternary geology and the basic morphostratigraphic framework, soil-geomorphic relations, and the available relative and chronometric age control. Each chapter closes with an explanatory model for fluvial response to climatic change in the particular study area.