ABSTRACT
Trend-surface analysis is designed to detect the general, or regional trend in a variable which can be mapped across, or within, an area. There are, inevitably, local deviations from any regional trend, and these may be a response to an underlying controlling influence or they may be random error values. Within geomorphology trend-surface analysis has been applied most commonly to data concerning the altitude of subaerial planation surfaces and raised beaches. Trend-surface analysis, like any other regression technique, produces a statement of both the general trend of the data and of the individual deviations of each observation from that trend. The higher the order of the trend-surface the more it can accommodate undulations in the mapped variable. When the predominant interest in any trend-surface analysis is to be focused upon the computed surface itself then certain conditions regarding both the data and the deviation values need to be fulfilled.
