Advances in modeling Land Dynamics in mountainous environments
Veldkamp, A., Schoorl, J.M., Claessens, L.,
Chair Land Dynamics
Wageningen University
P.O. Box 47
6700 AA Wageningen
The Netherlands
Mountainous landscapes are often strongly influenced by gravity dominated processes
such as rock fall & flow and landslides. These processes are usually related to
instabilities in slopes. It is usually possible to identify one or more location factors
that make a slope vulnerable to failure.
Of the main location factors, geological factors such as material properties and
morphological factors such as slope angle and length, been most intensively studied at
the landscape scale. Human factors, although often mentioned have not been
systematically studied within the landscape context apart from very obvious events
such as deforestation.
Given the location factors of mass movements it is not surprising that they usually
occur in areas with steep relief and relatively wet climates. In order to maintain steep
gradients the regions dominated by mass movements coincide with areas
characterized by rapid uplift rates. It is also for this reason that a lot of
groundbreaking research on landslides dynamics was done in areas along the Pacific
margin such as Japan, Taiwan, Philippines and New Zealand. These areas are
excellent to study landslides as they occur frequently at the landscape level.
Because landslides have a large societal significance in terms of their impact and
casualties it is essential to unravel the location factors, not only the more natural
unavoidable factors but also the factors that can be managed by policy measures, such
as land use/cover change and other actions that change local topography and
hydrology. These interactions between natural and human processes of processes are
often referred to as feedback mechanisms in the coupled human environmental
system. One way of studying these interactions in a controlled environment is by
means of modeling.
After giving an overview of current developments and challenges in land science
modeling, the focus of this presentation will be on the concepts of dynamic modeling
of feedback mechanisms between land use change and geomorphic processes.
Examples of water redistribution, land sliding and rock fall will be discussed. The
functioning of different types of feedbacks (bio-physical constraints and human
decision making) will be discussed. Preliminary conclusion is that we need to develop
new techniques to separate the different sources of uncertainties in these models in
order to gain meaningful insights in these feedbacks.