Environmental Engineering Reference
In-Depth Information
Alternative models were developed to predict the ecological impacts of different
projections of future tourism development. The impacts of alteration to the land-
scape were examined with change scenarios in relation to modeled policy changes
(these are described in Steinitz et al. 2005). The selection of scenarios was intended
to represent the widest reasonable range of possibilities concerning development
and conservation (Karish and Faris 2004). Each model assumed a different but
escalating level of development as measured by the number of beds of new tour-
ism facilities that were applied in the scenarios as being a representative marker of
tourism growth. Beds were allocated to different locations on the island using GIS
analysis along consequent developmental attributes such as new roads, recreational
facilities, and so on.
In order to evaluate these development changes on the land, the environmental
impact of the alternative futures was assessed in relation to their influence on
estimated species loss on Coiba (Karish and Faris 2004; Steinitz et al. 2005).
Different species were selected based on their rarity or endemism in the area
(Karish 2007). Some of the species, such as the scarlet macaw, were only found
on Coiba Island, whereas others were also found or predicted to occur on the
mainland. The amount of habitat and its quality (the latter broken down into the
three levels of primary, secondary, and tertiary) were mapped. Habitat was thus
tied to the predicted success of a suite of species under current land use condi-
tions as well as the varying future development impacts. Coral species were also
modeled in the same fashion.
An ecological impacts model was used to evaluate the influence of each sce-
nario's land use changes on the potential habitats of each of the selected species
as well as on the summary index of species richness (Karish and Faris 2004).
The proposed changes in land use for the scenarios were aggregated into groups
based upon their levels of disturbance associated with construction, maintenance,
or landscape modification. These groups were then assessed for the potential dis-
turbance in the area surrounding the site of the allocation. So, for example, when
a road was built, the greatest impact may be right beside the road, but there are
also additional impacts due to runoff beyond the site itself (Forman et al. 2003;
see also chapter 17). These surrounding areas and their associated disturbance
values were combined with the species habitat models to calculate the areas of
habitat that would be affected by the changes in each scenario. The calculated
map grid contained a range of values based on the cross between the sensitivity of
the habitat for that species and the severity of the projected impacts. The resulting
outputs could then be grouped into five general impact levels (Karish and Faris
2004). The impact could be beneficial, meaning there's a positive improvement in
habitat quality. This occurred for some species that actually exist better in edge
habitats or make use of agricultural lands. There could be a compatible impact,
in which case no perceivable changes are likely to occur in the landscape qual-
ity. There could be a moderate impact, meaning that maybe a natural mitigation
procedure might be necessary to alleviate the deleterious effects. Severe impacts
are possible, such that there would have to be some sort of engineering type of
solution in order to alleviate the impacts. And then, of course, terminal impacts
might occur in which case there is no possible mitigation. An example of this
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