ABSTRACT
Several factors interact to determine the form of an individual hillslope, but it is probably climate that has been the subject of greatest investigation. To some extent, of course, this interest in the role of climate stems from, and is part of, climatic geomorphology. The notion that different landform assemblages can be associated with different climates can be traced back to Davis's writings on the temperate fluvial cycle (1899), the arid cycle (1905) and the glacial cycle (1900, 1906). In the more recent past German and French geomorphologists (e.g. Biidel, 1948, 1963; Tricart and Cailleux (1965) have been particularly active in emphasising the role of climate in landform development. Within this general context some, though perhaps remarkably little, attention has been given to the question of climatic influences on hillslope form. For the broad category of sub-aerially formed hillslopes "surprisingly little objective morphometric evid ence exists .... and the recognition of distinct landform assemblages has depended less on total landscape morphometry than on the occurrence of less frequent but more spectacular type-landforms, such as inselbergs or pediments," (Stoddart, 1969, p.174)
The issue is a complex one involving several questions whose separate identity has not always been recognised. These questions are as follows:
(a) Does the form of hillslopes differ from one climatic zone to another? If so, is this because:
(i) climate affects hillslope form directly (i.e. by modifying the effects of processes) so that if all other factors
are held constant, differences in hillslope form will be observed solely as a result of moving from one climatic zone to another, or (ii) climate affects other factors con trolling hillslope form (e.g. surface materials, drainage density) so that the effects of climate are manifested only in an indirect way?
