Alkema, Dinand
INTEGRATED DATASETS, GIS AND 3-D SYSTEM ANALYSIS FOR ENVIRONMENTAL
IMPACT ASSESSMENT IN A LARGE ALPINE VALLEY NORTH OF TRENTO (ITALY)
D. Alkema!, D.Geneletti >, A. Cavallin ‘, Th. Van Asch ?, A. Fabbri ?, A. Zanchi ‘, M. De Amicis ', T. Bonomi ‘, F.
De Francesch ; A. Moltrer s L. Tomasi “.
! University of Milano - Bicocca, Italy
? ITC, Enschede, the Netherlands
? University of Utrecht, the Netherlands
* Geologic Survey of the Autonomous Province of Trento, Italy
>E.LA. office of the Autonomous Province of Trento, Italy
KEY WORDS: Analysis, Dynamic processes, Hazard, GIS, Model based processing.
.ABSTRACT
The incorporation of geomorphologic considerations in an Environmental Impact Assessment (EIA) is usually hindered
by the complexity of geomorphologic systems. This paper intends to make a contribution to integrate knowledge of
geomorphologic processes into EIA procedures. More detailed elaboration of geomorphologic systems through
modelling will enable to forecast change in indicators due to a development. As an example, the preliminary results of a
case study near Trento (Italy) are presented. The objective of this case-study is to show how the construction of a new
motorway will interact with the flood-propagation on the plain in case of a flooding. Such a study will be a contribution
to reduce flood risk.
1 INTRODUCTION
An environmental impact can be described as the change in an environmental parameter, over a specific period and
within a defined area, resulting from the development compared with the situation which would have occurred had the
development not been initiated (Wathern, 1989). The assessment of environmental impact (EIA) of a development has
become an important management tool in the decision-making process in many countries. It provides decision-makers
with a systematic analysis of the environmental consequences of a development, so that they can include environmental
considerations in the decision process (Beinat 1999).
Traditional EIA tends to focus on ecology and pollution. But many of the major effects are actually connected to the
physical and geomorphologic conditions (Cavallin et al., 1994). Important ecotopes for instance are often characterised
by their geomorphologic setting. This observation is not new, as can be demonstrated by numerous papers on the role of
geomorphology in EIA (e.g. van Asch & van Dijck, 1994; Rivas et al. 1994). Still few EIA-examples of are available
where geomorphology plays a central role. The inherent complexity and multi-disciplinary character of geomorphology
makes it difficult to integrate it into an EIA. A stepwise approach is needed.
2 GEOMORPHOLOGIC ASSETS AND PROCESSES IN RELATION TO A DEVELOPMENT
Panizza (1994) suggests to divide geomorphology into two main components: 1) processes, that can cause hazardous
situations; 2) assets, that comprise landforms and raw (extractable) materials. Geomorphologic hazards are natural
conditions that can cause loss of life or damage to property. They can be described as the probability that a certain
geomorphologic process will occur in a certain territory with a certain intensity in a given period of time.
Geomorphologic assets are sites or landscapes of great scientific heritage value or — in the case of raw materials — of
(potential) economic value. A development interacts differently with either of these two components according to
Cavallin et al. (1994) who identified five different potential effects:
direct impact: the development damages a geomorphologic asset;
indirect impact: the development induces another hazard that can cause damage to a geomorphologic asset;
risk: the possibility that the development is damaged due to a geomorphologic process (hazard);
direct risk: the possibility that the development changes the characteristics of a geomorphologic process (induced
hazard) which in turn may damage the development;
e indirect risk: the possibility of damage to the surrounding environment due to changes in the characteristics of a
geomorphologic process, caused by the development (induced hazard).
54 International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B7. Amsterdam 2000.
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