Michael F. Thomas
Articles
Extreme events in the context of late Quaternary environmental change
Geographia Polonica (2003) vol. 76, iss. 2, pp. 139-156 | 
Full text
Abstract
The significance of extreme events in landform change is discussed in the context of the late Quaternary. Millennia-scale cycles of climate change are less than the relaxation times of most landform systems and have led to widespread disequilibrium in natural landscapes. Slope failu-res and fluvial systems show parallel evolutionary trends in high and low latitudes, resulting from late Quaternary environmental changes. The transformation of geomorphic systems appears to require millennia of preparation time and research needs to establish the role of individual events within this timescale of enquiry.
Keywords: climate change, extreme events, fluvial systems, slope failures
, School of Biological and Environmental Sciences, University of Stirling, Stirling FK9 4LA, Scotland, UK
Purpose, scale and method in land resource surveys
Geographia Polonica (1977) vol. 34, pp. 207-224 | Full text
Abstract
The diversity and urgency of land use planning problems throughout theworld have led to a proliferation of reports and recommendations concerningland resource surveys and evaluations. These publications are notable as muchfor their different viewpoints as for their common aims, and recent attemptsto coordinate land classification procedures have not always clarified the issues.Many discussions appear to spring from an implicit assumption that all surveysshould have a common methodology and follow an accepted sequence of operations(Brink et al. 1966; Brinkman and Smyth 1972). Differences of purpose andof scale may invalidate such assumptions (Beckett 1968), but most if not allsuch surveys attempt spatial subdivisions of the land surface and are thereforeconcerned with the delimitation of areas having known properties of importanceto the prediction of land potential and performance under different uses ormanagements.
The identification and mapping of land areas (land units) at varying scalesof enquiry are therefore central aims and problems in land resource surveys.But many reports avoid discussion of issues inherent in such a situation. Furthermore,although most land units have been defined in part on the propertiesof their geological and geomorphological foundations, geomorphologists havecommonly ignored the difficulties underlying this task. Before exploring thissituation in greater depth a number of general principles may be considered.
, School of Biological and Environmental Sciences, University of Stirling, Stirling FK9 4LA, Scotland, UK