ABSTRACT

This chapter pursues the subject of the field-based view of phenomena, looking at the ways in which they are represented and analysed in surface models. The chapter describes surface modelling procedures which are found on a field-based view of geographic reality. Environmental studies of air and ground pollution and of the distribution of soil types and minerals also depend heavily upon the use of abstract surface modelling tecniques. The chapter introduces simple techniques of the interpolating unknown values from given sampled values, and also introduces the concept of spatial autocorrelation, which underlies a theoretical understanding of interpolation techniques. Surface representations consisting of discrete samples are usually based upon points or lines or a combination of both. A very versatile approach to surface representation is to triangulate the sample points to produce a Triangulated Irregular Networks (TIN). Point-sample representations may be either irregularly or regularly distributed.