Bertens, Jurjen
A number of such impacts are directly or indirectly related to geomorphological characteristics. For the purpose of an EIA
wh
within a geomorphological framework, a division can be made in three main groups of geomorphological components (Rivas inf
et al, 1997): (1) geomorphological resources (consumable); (2) geomorphological assets (non-consumable); and (3) anc
geomorphological processes. In the third group indirect, secondary, cumulative, etc. effects of impacts can be considerable. inf
When assessing impacts on processes, a problem arises due to the fact that predictions have to be made with respect to silt
dynamic rather than static qualities of the landscape. Impacts on static landscape features can be assessed with relatively
straight-forward methods. For example, consumable resources present in the area that will be affected by the activity can be
expressed as a volume and a corresponding market value. The volume change associated with the construction of the 3I
transportation system can be calculated and the comparison of pre- and post-values allows for a quantification of the impact
(Rivas et al., 1997). Impacts on dynamic landscape features will have to be evaluated in a different manner, since the impact
1
itself will be of a dynamic nature. Under certain conditions the use of models allows for deterministic or probabilistic 3
predictions. They are a tool which can contribute to the wider process of decision making, e.g. exploration of strategies, Fu
Although they cannot replace direct data sources, they allow the most to be made of existing data, where data are scarce or im]
unavailable such as data on future conditions (Bathurst & O'Connell, 1992). imi
ero
2 CASE STUDY Fu
prc
he study concerns the construction of the new Vitoria-Eibar (in
motorway in the Gipuzkoa territory (western part of the (an
Basque Country, Spain; figure 1). This motorway will provide
a shorter and faster link between the northern Castilian plateau If :
and San Sebastián and the French border. cot
in t
The length of the highway will be approximately 80 km and it an
will cross the Cantabrian Range from the Castilian Meseta to the
an area near the coast. A large part of the route will run am
through the watershed of the Deba River. The Deba River is de
situated in the most western part of the Gipuzkoa territory and
is 62 km long. Its watershed covers 539 km”. Annual average
rainfall and discharge are 1384 mm and 14,08m°s" mec AIRE 32
respectively. Figure 1 Location of study area
blastin excavation / i f machine operation ; I E
The goals to be achieved Leu accumulation ae and hea) Yshile ape s impacts d
through the construction of e are
the new motorway are |
new material
and landforms
: d D surface lithology
providing better conditions and landform
for economic development,
streamcourses
environmental
soil traffic components prc
of :
reducing the congestion of v | mo
National I road, reducing Introduction Stroamfiow LE a e] DO
deaths, injuries and damages of new chemicals SORA S
. LLA—— l1
due to traffic accidents and runoff sad bad effects In:
; ; ; infiltration qv 1 |
improving the environmental | v y WO
quality of urban areas erosion soil pre
affected by the present road. groundwater 1 quality ST
recharge sediment load Io
0
Main concerns with respect siltation SOI
to the potential impact of the AR’ ; des
motorway which have been groundwater surfacewater agricultural | concerns
initially identified are traffic quantity and quantity and productivity Re
increase through and at quay N flood hazard fos
either end of the new Y Y y Col
transportation axis resource human human productive | significant
: t or base health safety sectors qualities
introduction of a barrier
Figure 2 Expected effects on hydrology and related processes due to motorway construction
176 International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B7. Amsterdam 2000.