Chapter 16
Clean and Healthy – Natural Hazards
and Resources
Carlo Bisci, Bernardino Gentili, Alessio Acciarri, Gino Cantalamessa,
Giorgio Di Pancrazio, Massimiliano Fazzini, Alessandro Fusari,
Matteo Gentilucci, and Maria Chiara Invernizzi
Data Sources
To identify natural hazards and resources, we used publicly available data with good
homogeneity. In particular, we used:
– vector Regional Technical Maps (CTR), 1:10,000: http://www.ambiente.marche.it/
Territorio/Cartografiaeinformazioniterritoriali/Archiviocartograficoeinformazion
iterritoriali/Cartografie/CARTATECNICANUMERICA110000.aspx
– raster Regional Geological Maps (CARG), 1:10,000: http://www.ambiente.marche.
it/Territorio/Cartografiaeinformazioniterritoriali/Archiviocartograficoeinformazion
iterritoriali/Cartografie/CARTAGEOLOGICAREGIONALE110000.aspx
– raster Regional Geomorphological Maps (CARG), 1:10,000: http://www.ambiente.
marche.it/Territorio/Cartografiaeinformazioniterritoriali/Archiviocartograficoe
informazioniterritoriali/Cartografie/CARTAGEOMORFOLOGICAREGION
ALE110000.aspx
– raster Regional Soil Maps (ASSAM) 1:50,000: http://suoli.regione.marche.it/
ServiziInformativi/Cartografia.aspx
– Landsat 7 multispectral imagery; http://earthexplorer.usgs.gov/
– vector Land Use Map CORINE, 2012, level 3: http://www.sinanet.isprambiente.
it/it/sia-ispra/download-mais/corine-land-cover/corine-land-cover-2012/view;
– climatic records from SIRMIP: http://84.38.48.145/sol/indexjs.php?lang=it.
C. Bisci (*) • B. Gentili • A. Acciarri • G. Cantalamessa • G. Di Pancrazio • M. Fazzini
A. Fusari • M. Gentilucci • M.C. Invernizzi
School of Science and Technology, University of Camerino, Camerino, Italy
e-mail: carlo.bisci@unicam.it; bernardino.gentili@unicam.it; alessio.acciarri@gmail.com;
gino.cantalamessa@unicam.it; giorgio.dipancrazio@unicam.it; massimiliano.fazzini@unicam.it;
alessandro.fusari@unicam.it; matteo.gentilucci@unicam.it; chiara.invernizzi@unicam.it
© Springer International Publishing Switzerland 2018
R. Cocci Grifoni et al., Quality of Life in Urban Landscapes,
The Urban Book Series, https://doi.org/10.1007/978-3-319-65581-9_16
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Natural Hazards
Natural hazards are weaknesses and threats that limit land use and transformability
and negatively influence the quality of life, both directly and indirectly.
Floods
Following intense rainfall (and/or fast snowmelt), rivers may overflow, inundating
part of the neighbouring plains. This natural behaviour may result in a locally high
hazard rate.
As a rule, flood-prone areas are identified based on the maximum flood in the last
century, possibly applying a safety margin. Unfortunately, in recent decades, many
streams have been rectified, narrowed, and/or diverted (mostly in their mid/final
reaches) by building levees, thus strongly modifying flood dynamics and the geometry of flood-prone areas. Moreover, land-use modifications in river basins have
changed both ground permeability and runoff features, while interventions along
the streams have modified the flooding behaviour. In addition, narrow bridges often
constitute an important obstacle to the free flow of debris (mostly tree trunks) carried by floods, thus causing upstream overflows. Anthropogenic modifications
accompanied by climate change have resulted in an increase in both frequency and
intensity of heavy rainfall. As a consequence, historical climate records should be
used while considering recent trends.
Based on these considerations, flood-prone areas were identified based on their
elevation above the levees and on the elevation of the levees over the thalweg, classifying them according to the presumed water depth.
Mass Movements
The potential energy of a terrain derives from its relief (i.e. elevation over the valley
bottom). This is naturally transformed into kinetic energy (i.e. down-slope movement) whenever resistant forces are weak.
Therefore, potential slope instabilities should be studied based on detailed analyses of both the spatial distribution of the mechanical properties of terrains and their
variations deriving from other factors (e.g. water saturation, seismic shocks, etc.).
Unfortunately, this approach was not affordable in this project. The analysis was
therefore based on available geological and geomorphological maps, digitizing the
polygons corresponding to the landslides identified, maintaining their classification
(Cruden and Varnes 1996), and merging active and dormant phenomena.
The danger and possibility of stabilizing the mass movements were evaluated
based on their speed (inferred from their type and slope) and dimension (surface
area, since no thickness data is available).
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Soil Erosion
Runoff deriving from intense precipitation causes the removal of material (mostly
fine grained) from the uppermost soil layer, resulting in thinning and a local reduction in crop productivity.
To evaluate the rate of this phenomenon, we adopted the RUSLE (Revised
Universal Soil Loss Equation; USDA, 2014), simplified according to the available
data. An evaluation of slope angle was based on the TIN, calculated based on the CTR
(manually corrected where appropriate). Soil types were inferred based on the regional
maps produced by ASSAM (2006), redrawing the boundaries according to local topographic and geological features. Due to a lack of better maps, vegetation and crops
were evaluated based upon the CORINE (EEA, 2010) level 4 map, attributing an
average index of the most common local crops to arable areas. Precipitation was
regionalized starting from the SIRMIP records, and topography was also considered.
Only areas with a high erosion rate were included in the hazard evaluation.
Coastal Erosion
Sea waves reshape beaches, transporting finer sediments offshore during severe
storms. If these sediments are not replaced (mostly with debris carried by rivers as
solid load), shorelines retreat, exposing inland areas to storms and locally undermining cliffs, thus inducing slope instability.
The study area has been affected by shoreline retreat in the last century as a result
of many natural factors (the current wet, warm climate favours vegetation growth,
thus reducing soil erosion and, in turn, the solid load of streams) and anthropogenic
factors. In recent decades, dams and check dams have been built, blocking debris
upstream; fields were also abandoned, thus reducing soil erosion. Moreover, until
the late 1970s, debris was dug up from riverbeds, reducing the solid load and locally
reaching the (mostly pelitic) bedrock. As a result, severe shore retreat has been
counteracted locally by adopting different types of countermeasures (transverse
barriers, breakwaters, groynes, artificial nourishment, etc.). However, most of these
measures interfere with shore dynamics, making the study of evolutionary beach
trends more complex and locally worsening the situation.
Continuous, long-term monitoring of beach profiles accompanied by an accurate
analysis of local wave climates and the features of neighbouring river basins is required
to accurately evaluate local trends. Since this procedure is beyond the scope of this
project, we have simply distinguished between artificially protected and “natural”
beaches (delimiting the latter), taking into account the average features of local storms.
Seismic Shocks
As in most of Italy, the study area is tectonically active. Based on the available
instrumental data, it was possible to define the range of earthquake intensities that
could be possible in the future.
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Since the area is quite small, the intensity of such a seismic shock can be taken
to be homogeneous throughout the area. Therefore, to evaluate seismic risk, we
based the analysis upon scenarios capable of increasing the vulnerability of exposed
artefacts and buildings.
For conditions inducing an increase in shaking, the DEM was used to map the
morphological irregularities (scarps, peaks, and ridges) and loose granular terrains
(sand and gravel) based on the geological maps. With the same geological maps,
stratigraphic contacts and tectonic lines, which could potentially result in differential shaking, were identified, along with the areas where saturated sands may lead to
liquefaction (i.e. alluvial deposits).
Climate
Climate has always profoundly influenced urbanization and land use, as well as the
quality of life. Particularly relevant aspects include extreme precipitation, droughts,
severe sea storms, very high summer temperatures, and gusts of wind. Statistics
demonstrate that on average, all these phenomena have become increasingly frequent and intense almost everywhere (IPCC 2014). Global climate change has a
high spatial and interannual variation, thus making the analysis of local time series
more complicated, since short- and midterm trends need to be identified for every
parameter investigated. It is also necessary to recognize that older structures were
often built based on the distinctly different needs of the Little Ice Age, which ended
in the eighteenth century. Similar considerations can be applied to trees that are
more than a hundred years old.
Considering the climate of the area of interest, the study of climatic hazards was
limited to identifying potentially vulnerable sites and areas where heat peaks may
be higher and evaluating the probability of particularly strong sea storms. All the
studies above were based on climate records available at the SIRMIP website, yielding an acceptable assessment of the study area. Since the area is quite small, precipitation was considered to be homogeneous throughout.
Flood-prone areas were based on the DEM, mapping hollows (both natural and
anthropic), and bottlenecks located at the foot of a sufficiently wide catchment area.
To evaluate heat peaks, the spatial distribution of theoretical insulation was calculated using the DEM once more and compared with local albedo and vegetal biomass
deriving from multispectral remote-sensing imagery (Landsat 7/8 TM). Particularly
strong potential sea storms were examined to analyse possible shoreline retreat.
Volcanoes
Volcanoes are among the most dangerous natural phenomena. However, since volcanism has never affected the area under consideration, we have disregarded this
type of hazard.
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Glaciers
Ice and frost significantly influence land use and the quality of life, but considering
the climate of the area, they were not taken into account.
Natural Resources
Natural resources represent strengths and opportunities. When used and managed
wisely, they may significantly contribute to enhancing the value of territory and
improve the quality of life.
Water
Water is the main source of life, not just for humans; it is also a source of socioeconomic development. Therefore, it is instrumental to identify and characterize, as
well as enhance and protect, water resources, particularly those offering highquality drinking water.
The study area encompasses both large (Monte Conero) and minor but nonnegligible calcareous aquifers housed within coarse-grained turbidite levels (sandstones and conglomerates) lying between predominantly pelitic levels, as well as
(often polluted) sand-gravel alluvial deposits, and ancient beaches. Given the type
of research, individual aquifers were not studied or evaluated. Instead, these three
types of reservoirs were merely distinguished based on the geological maps.
Seas/Lakes
Seas and lakes represent remarkable natural resources. They constitute a very
important line of transportation, provide food through fishing and fish farming, generate wealth through the tourism industry, offer recreational opportunities to inhabitants, and represent strong landscape value.
All sea and lake evaluations were based on the topographic map and the
DEM. The port area was not classified according to its use (commercial, touristic,
etc.), since this matter is more typical of urban analyses. As for fishing, only areas
offering the opportunity to fish from the shore were mapped. Touristic attractiveness
and recreational potential were evaluated by mapping all accessible beaches without
marking distinctions. The landscape value of the sea was evaluated among the landscape resources.
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Landscape
The physical environment may hold primary landscape value. Therefore, the presence of relevant sites (geosites, relevant geological and geomorphological features,
etc.) may not marginally increase the quality of life besides representing a noticeable natural resource.
In the study area, all the relevant sites were mapped based on the geological and
geomorphological maps. Moreover, based on the DEM, an intervisibility analysis
was performed to identify all the places from which they are visible.
Climate
A sound knowledge of the climate is instrumental for urban planning and evaluating
the quality of life, especially in this period of rapid change.
Potentially “favourable” climatic features such as natural resources were therefore considered, mapping (using criteria similar to those adopted for the climate
hazards) all the areas deemed “fresh” on summer days and those considered to have
a milder climate in winter. Based on the annual and seasonal distributions of insulation, we also mapped the most productive potential sites for solar energy.
Unfortunately, without detailed data regarding wind distribution, it was not possible
to make a similar study for the installation of wind generators.
Geothermal Energy
In a general context of being increasingly aware of problems connected to the production of greenhouse gases and other pollutants, alternative eco-friendly sources of
energy should be strongly encouraged. Within this framework, the study of anomalous geothermal gradients is particularly relevant.
This type of investigation, however, requires detailed temperature data taken in
perforations at different depths. Lacking these, we could only reconstruct a geological structural model according to which it would be possible to more accurately
interpolate any geothermal data produced in the future.
Minerals
Humans have always extracted from the Earth the elements needed to develop and
adopt technologies. The presence of this type of usable resource is therefore a very
relevant natural resource for the economy of any area. Unfortunately, to our knowledge, no relevant deposit has ever been found or hypothesized in the study area, and
this important theme was therefore not addressed.
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Classification
Classification of the various phenomena was simplified as much as possible, reducing the number of hazard classes to six and resource classes to four.
Natural Hazards
Disregarding their typology, dimension, and genesis, potentially hazardous phenomena were classified into three merely qualitative classes of increasing potential hazard (“high”, “intermediate”, and “low”, corresponding to codes “A”, “B”, and “C”,
respectively). In turn, each of these classes was divided into two subclasses according to the possibility of reclaiming or recovering the area affected by the phenomenon, assigning a second digit to the code: “1”, for areas where recovery is unlikely
or impossible, and “2”, where its substantial recovery could be possible (Table 16.1).
Floods
Hazards deriving from potential flooding were assessed by evaluating the maximum
possible level reached by cresting water, using the following codes: “A”, where it is
more than 1 m above ground level; “B”, where it is between 30 cm and 1 m; and
“C”, where it is less than 30 cm. Wherever it appears possible to build an adequate
levee, the second digit “2” was applied, otherwise it was “1”.
Mass Movements
High hazard values were attributed both to fast landslides (only rock falls in the
study area), because of their danger for people, and to presumably thick slower ones
(only rotational slides in the study area), capable of severely damaging most structures. An intermediate value was attributed to other non-superficial mass
Table 16.1 Classification codes
and representation for natural
hazards
Code
Hazard
A1
Raclaim /
Recover
No
High
A2
Yes
B1
No
Intermediate
B2
Yes
C1
No
Low
C2
Yes
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movements (minor rotational slides in this area), which can damage structures that
are not particularly resistant. The lowest value was assigned to surface phenomena
(earth flows in this area) and plastic deformations. Only for larger rock falls and
deep-seated landslides do present-day techniques not reasonably allow for
reclamation.
Soil Erosion
Where the erosion rate (in T ha-1 y-1) exceeds 6 (OCSE 2001), the hazard was
considered to be intermediate, and where it ranges from 2 to 6 mm/year, it was considered to be low. Since agricultural practices can significantly reduce erosion,
wherever the slope angle is lower than 20%, the area was classified as recoverable.
Coastal Erosion
Lacking any long-term monitoring of beaches, we were unable to evaluate their
actual erosion rate. Therefore, an intermediate hazard value was assigned to nonprotected beaches, extending up to 20 m inland. All of them were classified as
recoverable, since both relatively simple interventions (artificial nourishment) and
more intensive engineering works can always be carried out.
Seismic Shocks
We assigned a high hazard level to the 10-m-wide belts running along lithologic
boundaries and tectonic discontinuities; all other scenarios were classified as intermediate. Only highly hazardous areas were classified as non-remediable, since technical measures are always viable for the remaining situations.
Climate
All climate hazards were classified as low, since flooding phenomena are not
expected to result in severe damage and heat peaks are never extreme. All the situations above were considered to be remediable since for flood-prone areas, drainages
and/or sewage systems can solve the problem, and “hot” sites can be cooled with
shading devices or vegetation.
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Table 16.2 Classification codes
for natural resources
Code
Relevance
a1
Exploitable
Yes
High
a2
No
b1
Yes
Moderate
b2
No
Natural Resources
Natural resources were classified into two levels of relevance (“high” and “moderate”, coded “a” and “b”, respectively). The second digit of the classification indicates the possibility of exploiting the resource (1 for exploitable ones; 2 for weakly
exploitable ones) (Table 16.2).
Water
High relevance was attributed to the calcareous and larger turbidite aquifers (i.e.
those potentially providing a noticeable amount of water throughout the year). Low
relevance was assigned to minor turbidite aquifers and those located in suspended
alluvial deposits because of their reduced volume. This group also includes those
directly in contact with rivers, because of the very low water quality. Present-day
beaches were disregarded because of the presence of salt water close to the ground
surface. Lacking systematic data on the depth of and seasonal fluctuations in the
water tables, as well as the chemical properties of the water, all aquifers were classified as exploitable.
Sea
Except for the harbour area, the entire 5-m-wide belt bordering the shoreline was
classified as adequate for fishing, attributing a low relevance to it. All accessible
beaches were classified as highly relevant. Both were classified as exploitable
whenever they can be easily accessed from inland.
Landscape
All natural peculiarities were classified as highly relevant. Low relevance was
attributed to the sites from which they are visible. All accessible sites were classified
as exploitable.
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Climate
Both areas identified as “fresh” in summer or “warm” in winter were considered to
have a low relevance, since thermal differences are not very high. Similarly, sites
characterized by a theoretically higher insulation were considered to have low relevance, since again, the differences are not striking. The exploitability of these sites
was also based upon accessibility.
Database and Mapping
All the basic information layers were stored in a geodatabase (georeferencing and
digitizing them when necessary). Natural hazards and resources, classified as briefly
described above, were stored in the same geodatabase as vector layers with an associated attribute table describing whatever was deemed important for the project in
each situation. Points and polygonal chains were converted into polygons by applying an adequate buffer depending on the potential area of influence of each.
Each of the above polygon layers was then rasterized according to a regular grid
(cell size 5 m) containing the code attributed to each type of phenomenon. From
these rasters, two maps portraying the overall hazards and resources were created,
attributing to each cell the maximum value present in any of the source maps. These
maps were then converted into polygonal maps with representations according to
Tables 16.1 and 16.2.
The map of natural resources (varying shades of green) was then superimposed
on the map of natural hazards (full colours, shades from yellow to red) to obtain a
synthetic map representing the spatial distribution of the influence of the physical
environment on the territory and the quality of life. This map can be easily superimposed on other maps produced by other working groups within the framework of
this project.
All steps in this study were carried out using ESRI ArcGIS ArcInfo (Lab of GIS
and Computer-Assisted Mapping, University of Camerino, principal investigator:
Prof. C. Bisci).
References
ASSAM (2006) Carta dei Sottosistemi di terre in scala 1:250.000. http://suoli.regione.marche.it/
ServiziInformativi/Cartografia.aspx
Cruden DM, Varnes DJ (1996) Landslide types and processes. In: Turner AK, Shuster RL (eds)
Landslides: investigation and mitigation, Transportation Research Board, Special Report 247.
Transportation Research Board, Washington, pp 36–75
European Environment Agency (2010) Land use—SOER 2010 thematic assessment. http://www.
eea.europa.eu/soer/europe/land-use
IPCC (2014) Climate change 2014. Synthesis report. http://www.ipcc.ch/report/ar5/syr/
OCSE (2001) Environmental indicators for agriculture. http://webdominio1.oecd.org/comnet/agr/.