| dc.description.abstract | The scale 'jump" in hydrology and agriculture from the ,small scale at which individual processes such as infiltration, soil
water redistribution, evapotranspiration, soil loss or crop development/yield have been studied, to the global scale at which
climate change impacts and international trade in agriculture manifest themselves, has presented agrohydrologists with conceptual
as well as practical problems of scales and scaling. In this context, selected scaling issues are, therefore, identified and
highlighted. The paper discusses why scaling problems arise, defines concepts and types of scales, poses what are considered
key questions with regard to up scaling and down scaling, as well as to dis-aggregation to homogenous landscape response units
(HLRUs and to re-aggregation. Examples from southern Africa are then given of space/time scaling approaches, ranging
from country to local-scale levels, followed by an evaluation of types of errors associated with scaling. The paper concludes
by identifying what, in the author's perception, some of the challenges are which relate to scaling applications of the "real
world" I d which hydrologists and agriculturists face in the next few years | en |
