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M.G.C. Martins & J. Aranha 2010. Electrical network hazard assessment for the avifauna in Portugal
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Table 2: Electrical power line classification, according to hazard level
Electrocution
Collision
Class Death_class Number of lines Length (km) Length (%)
1 [0 ; 0,83] 6447 1597,375 9,21
2 [0,83 ; 1,66] 4386 1698,577 9,79
3 [1,66 ; 2,49] 14926 6024,488 34,72
4 [2,49 ; 3,33] 11267 4899,044 28,24
5 [3,33 ; 4,16] 8223 3130,009 18,04
1 [0 ; 1,32] 6248 2649,333 17,28
2 [1,32 ; 2,65] 9360 3439,777 22,46
3 [2,65 ; 3,97] 10557 3761,530 24,53
4 [3,97 ; 5,30] 6365 2356,527 15,37
5 [5,30 ; 6,63] 7685 3128,657 20,40
Final results enable to state that Portuguese country areas with lower degree of birds’ electric
shock danger are: the north and part of the center, as well as the southwestern district of Lisbon,
and the coastline of the districts of Setúbal and Beja.
In the districts of Guarda, Castelo Branco; Bragança, Braga, Porto, Portalegre, Santarém (North),
Setubal and Viana do Castelo dominates the middle class of danger (see Figure 1 for location).
The regions under high hazard level are: the districts of Évora, Santarém (South), Lisboa
(northeast) Beja (central and northern) and Faro.
According to the power line network characteristics and location, the south of Portugal is the
results most concern as well the central coast.
4. Discussion
The objectives of this study were successfully achieved. The entire power line net work was
classified and analysed, for the entire country, the relationship between power network and
environmental characteristics, with special relevance for Natural Regions and Protected Areas.
We would like to highlight the following results:
the worst case scenario, related to collision hazard, indicates that the high and very high hazard
classes of collision are present in more than 36% of the total analysed kilometres,
for electrocution hazard, the worst forecast indicates the prevalence of high and very high
hazard classes in approximately 50% of the total analysed kilometres.
These results are worrying in terms of ecology, and should wherever possible, be eliminated or
minimised in order to reduce negative effects on avifauna,
for Natural Regions and Protected Areas, the results indicate that the high and very high hazard
classes of collision are present in more than 43% of the total analysed kilometres, the high and
very high hazard classes of electrocution are present in more than 34% of the total analysed
kilometres and 43% classified as middle class.
References
Bernhardsen, T. 1999. Geographical Information Systems, an introduction – Second
Edition. John Wiley & Sons, Inc. New York. U.S.A.
Forest Landscapes and Global Change-New Frontiers in Management, Conservation and Restoration. Proceedings of the IUFRO Landscape Ecology
Working Group International Conference, September 21-27, 2010, Bragança, Portugal. J.C. Azevedo, M. Feliciano, J. Castro & M.A. Pinto (eds.)
2010, Instituto Politécnico de Bragança, Bragança, Portugal.