Environmental Engineering Reference
In-Depth Information
support embedded models with more realistic spatial characteristics of the entities,
than simple box models. The capabilities of a GIS are eminent: it can calculate
dimensions of objects (even if they are dynamic) represented in different coordinate
systems and projections. Together with information on the velocity of processes,
the according rates can be calculated. Being spatially explicit, it is possible to
connect data and models based on their determined location.
Nevertheless, attention has to be focused on the spatial fitting of the data,
models and methods. Distribution of abiotic as well as biotic phenomena tend to
be heterogeneous and inconsistent. The representativeness of the measurements
has to be secured. Especially in complex systems, driving forces and resulting
impacts might act on different spatial levels (Levin 1992) underpinning its
importance (Schreier et al. 2002). Naiman (1992) argues a number of issues
related with the possible mismatch of scales. Important issues concerning man-
agement aspects are:
1. The mismatch between local controls and system-wide needs and priorities.
2. The discrepancy between the scale or level of available factual information and
the dimension of a phenomenon, e.g. between the catchment level and the level
at which important decisions are made (Aspinall et al. 2000).
3. An absence of systematic investigation of processes on a suitable scale.
Furthermore, on a more institutional level, misfits between natural system
boundaries and legal units can exist (Young 2003). Institutional arrangements
like administrational units or protected areas are not necessarily based on natural
borders (and vice versa). Especially in the context of resource management and
environmental politics, solving the conceptual problems arising from fixed but not
fitting borders is a challenge: the validity area of an environmental law might end at
a border, but ecosystems' patterns and processes do not. Transition sections and
buffer zones (created by a GIS tool) are appropriate technical and conceptual
methods dealing with this aspect of spatial fitting.
22.3.1 Methods of Integration
Consideration of dynamics requires specialized integrated approaches. IEM are
supposed to describe spatial and temporal distributions of the entities and should
consider the different units and conceptual levels of the parameters. Consequently,
they need to deal with a high level of complexity. Moreover, to answer questions of
management and policy making, they have to provide information from diverse
institutional levels, rather than any conceptual level or scale.
Various functions offered by common GIS-applications support coupling of data
and models and aggregating of the resulting information. The following workflow
focuses on the main steps in a common software framework.
As an example, Fig.
22.3
shows the stepwise integration of a simple model on
land use. Integration aims to identify areas that are based on the intensity of land
