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_16 195 196 C. Bisci et al. 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). 16 Natural Hazards and Resources 197 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. 198 C. Bisci et al. 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. 16 Natural Hazards and Resources 199 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. 200 C. Bisci et al. 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. 16 201 Natural Hazards and Resources 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 202 C. Bisci et al. 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. 16 203 Natural Hazards and Resources 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. 204 C. Bisci et al. 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/.