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| Titel |
Uncorrected land-use planning highlighted by flooding: the Alba case study (Piedmont, Italy) |
| VerfasserIn |
F. Luino, L. Turconi, C. Petrea, G. Nigrelli |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1561-8633
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| Digitales Dokument |
URL |
| Erschienen |
In: Natural Hazards and Earth System Science ; 12, no. 7 ; Nr. 12, no. 7 (2012-07-24), S.2329-2346 |
| Datensatznummer |
250010996
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| Publikation (Nr.) |
 copernicus.org/nhess-12-2329-2012.pdf |
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| Zusammenfassung |
Alba is a town of over 30 000 inhabitants located along the Tanaro River
(Piedmont, northwestern Italy) and is famous for its wine and white
truffles. Many important industries and companies are based in Alba,
including the famous confectionery group Ferrero.
The town suffered considerably from a flood that occurred on 5–6 November 1994.
Forty-eight percent of the urban area was inundated, causing severe
damage and killing nine people. After the flood, the Alba area was analysed
in detail to determine the reasons for its vulnerability.
Information on serious floods in this area since 1800 was gathered from
official records, state technical office reports, unpublished documents in
the municipal archives, and articles published in local and national
newspapers. Maps, plans and aerial photographs (since 1954) were examined to
reconstruct Alba's urban development over the last two centuries and the
planform changes of the Tanaro River.
The results were compared with the effects of the November 1994 flood, which
was mapped from aerial photographs taken immediately after the flood, field
surveys and eyewitness reports.
The territory of Alba was subdivided into six categories: residential;
public service; industrial, commercial and hotels; sports areas, utilities
and standards (public gardens, parks, athletics grounds, private and public
sport clubs); aggregate plants and dumps; and agriculture and riverine
strip. The six categories were then grouped into three classes with
different flooding-vulnerability levels according to various parameters.
Using GIS, the three river corridors along the Tanaro identified by the
Autorità di Bacino del Fiume Po were overlaid on the three classes to
produce a final map of the risk areas.
This study shows that the historic floods and their dynamics have not been
duly considered in the land-use planning of Alba. The zones that were most
heavily damaged in the 1994 flood were those that were frequently affected in
the past and sites of more recent urbanisation. Despite recurrent severe
flooding of the Tanaro River and its tributaries, areas along the riverbed
and its paleochannels have been increasingly used for infrastructure and
building (e.g., roads, a municipal dump, a prison, natural aggregate plants,
a nomad camp), which has often interfered with the natural spread of the
floodwaters. Since the 1994 flood, many remedial projects have been completed
along the Tanaro and its tributaries, including levees, bank protection,
concrete walls and floodway channels. In spite of these costly projects, some
areas remain at high risk for flooding.
The method used, which considered historical data, river corridors
identified by hydraulic calculations, geomorphological aspects and land-use
planning, can indicate with good accuracy flood-prone areas and in
consequence to be an useful tool for the coherent planning of urban
expansion and the mitigation of flood risk. |
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