UHI in the Metropolitan Cluster of Bologna-Modena: Mitigation and Adaptation Strategies

  • Stefano Zauli SajaniEmail author
  • Stefano Marchesi
  • Paolo Lauriola
  • Rodica Tomozeiu
  • Lucio Botarelli
  • Giovanni Bonafè
  • Graziella Guaragno
  • Federica Fiumi
  • Michele Zanelli
  • Lodovico Gherardi
  • Marcello Capucci
  • Catia Rizzo
  • Filippo Bonazzi
Open Access


The pilot action took place in a district of Modena, the Villaggio Artigiano, characterized by the presence of disused small industrial buildings, which is part of a wider redevelopment context and regeneration process.

The innovative mixture of instruments proposed by the Municipality to better re-use the territory and to estimate the environmental restoration achieved with the urban interventions, is a starting point to give the planner flexible and easy to use instruments.


Cluster Bologna-Modena Villaggio Artigiano Urban redevelopment Urban planning Urban indexes 

6.1 Implementing Solutions for Climate Change in Urban Context

The effect of climate change on urban scale is often seen as a simple projection of a global risk. In fact, the urban environment is certainly characterized by particularly critical in relation to the effects of extreme events alluvial and heat waves, which is closely connected to the “climate change”. In reality, however, the local and the global influence each other mutually shaping opportunities and constraints. In this sense, an integrated approach to mitigation and adaptation is the only way to reduce the impact of climate change and to turn a threat into an opportunity for sustainable territorial development, economic and social too.

Measures to reduce heat island effect in this regard are a prime example of an action that fits both the perspective of adaptation to climate change and their mitigation. Reduce hardship bioclimatic in urban involves not only the ability to innovate in terms of use of materials and construction techniques but also to change economic and social structures, ensuring over time the quality of life and the environment.

In this chapter we want to draw a picture of the relevance of the heat island phenomenon in relation to climate change and illustrate the potential of the interventions of urban planning. The urban heat island is certainly one of the best known effects of urbanization on local climate.

6.2 The Metropolitan Cluster Of Bologna-Modena

6.2.1 Urban and Environmental Framework

Emilia-Romagna Region’s territory, in the Padan area, includes the metropolitan area of Bologna and other main conurbations located in the Emilian area and in the coastal area. The first main urban conurbation develops from Bologna along via Emilia (Emilia Street), including the cities of Modena, Reggio Emilia up to Parma, and is characterized by high density settlements with high-intensity exchanges; the second one, distributed along the coastline, concerns the intensely built-up touristic area from Rimini to Cervia.

Emilia-Romagna’s location makes it part of two National corridors which respectively connects the Apennine Mountains to the Adriatic Sea and North and South Italy, including: A1 and A14 highways, Piacenza-Rimini railway and a stretch of the high speed railway Milan-Bologna-Rome. Consequently, with a road network of 10.792 Km (which consists of 643 Km of highways and connection roads, 2907 Km of state roads and 7242 Km of provincial roads), the region has a key role for transport integration within National and European contexts (Fig. 6.1).
Fig. 6.1

Hierarchy of urban centres – Road and rail network

In the past forty years, a high intensity construction activity has affected the region and this has led to the spreading of settlements and of production and service sector activities. The main cities have lost inhabitants to the hinterland and consequently a sort of “city-area” characterized by a high and widespread urbanization index (153 inhabitant/kmq) has grown along via Emilia.

In addition to that, during the past twenty years Bologna’s metropolitan area has doubled, and the conurbations of central Emilia and along the coastline (where the 50 % of the regional population lives). have been affected by an increase in urbanization and land consumption up to 8–13 % of the total surface (Fig. 6.2).
Fig. 6.2

Urbanization 1976-2008

The pilot area is located in the core of this regional system described above. It is among the more developed areas at the regional and European level as far as its socio-economic development is concerned. The three provinces of Bologna, Modena and Reggio Emilia host 56 % of the regional industries. The local economy is based on the manufacturing sector, especially ceramic, which contributes to make Modena’s province a key productive centre within Europe.

The presence of firms, together with service providers and houses, has a negative impact on road conditions and on the quality of live in the cities and it is the cause of polluting emissions reaching emergency levels for increasingly longer periods. The use of renewable energies in this area is also still low.

In the metropolitan cluster of Bologna-Modena, despite the presence of some of the bigger rivers in the region, the high density settlements (which characterize the area) have reduced the space for natural environment. Furthermore, the development of man-made infrastructures has a negative impact on landscape and creates more obstacles to policies aimed at (1) integrating the metropolitan areas of Bologna and Modena; (2) decongesting the central areas (along via Emilia) and (3) mitigating the environmental alterations linked to critical traffic conditions (air and noise pollution), which have negative consequences, especially on the health of children and the elderly; (4) improving the connection infrastructures and public transport.

The regional climate is sub-continental with strong difference between summer and winter: summers are hot and muggy and winters are cold, rainy, foggy, moderately snowy and long. On average, the temperature reaches minimum values at dawn and maximum during mid-afternoon. Since 2001 an absolute maximum of 38,7°C and a minimum of −10°C has been detected.

The urban area of Modena is usually hotter and drier than the rural one. The biggest temperature differences are at night, and go from 2 °to 8°C, especially in the summer.

Furthermore, while variations in humidity tend to be wider at night, they can also be quite considerable in the daytime, during the winter months.

During the last 20 years the climate has undergone a strong change, if compared to the period 1961–1990: the average temperature has increased (+1,1 °C) and so has the maximum temperature (especially in summer, + 2 °C) and changes have been registered with regards to seasonal cycles and the intensity of rainfall.

Issues such as the quality of the air, energy and water cycles, renewable energy and land consumption reduction have been set as priorities by the regional governments.

Appendix A contains rules and regulation set up by Emilia-Romagna local governments and Appendix B contains a summary of incentives, financing and regulatory actions implemented at local levels to facilitate a sustainable land use and to support environmental restoration, energy conservation and reduction of phenomena related to climate change.

6.2.2 Pilot Area Identification Methodology and Description

Emilia-Romagna Region has decided to select the pilot area of the “Villaggio Artigiano” (Craftsman Village) in Modena as the Administration was preparing the Municipal Operational Plan (POC prescribed by the regional planning law) called “Urban Redevelopment of the West Face of Modena”, and expressed an interest in experimenting and integrating practical solutions aimed at containing the UHI phenomenon into urban planning (Fig. 6.3).
Fig. 6.3


In this framework, the Municipality of Modena has concluded the approval of a specific Plan of Urban Redevelopment of the Villaggio Artigiano (

Given the new environmental context in which the Village is included, the plan entails interventions aimed at fostering high-performance at the overall urban as well as environmental systems.

The pilot action lies in the urban area of Modena, in the western sector of the city; this is an area which might have been considered “almost suburban” until recently, but is now a rather central location of the city. Today, the Villaggio Artigiano is an area that is immediately identifiable by its unique triangular shape, framed by two streets coupling to the surrounding urban fabric and by the historical Bologna-Milano railway line (Fig. 6.4).
Fig. 6.4

Villaggio Artigiano – Planimetry

The idea of the Village was conceived in 1954. Modena’s municipal authorities decided to create a “craft area”, after the economic crisis of the postwar period, with the aim of boosting the economic recovery.

The Council allocated 15 ha of land to a “village for craftsmen” on the far western outskirts of the city, in the district Madonnina.

Within six years, 74 new companies, their owners, new entrepreneurs (especially workers who had been laid off by large companies, people with specific expertise) found a place and started their trade in the wasteland between the railway and the Via Emilia.

Participation in the project, however, greatly exceeded the initial expectations of the Administration: the two triangular areas divided into 60 lots initially planned were immediately granted, the Village was then extended to the current size (almost 500,000 square meters), with about 200 businesses set up.

The “Villaggio Artigiano” presents a building structure that is rather recognizable even nowadays: perpendicular roads constitute a mesh with traditional orientation, deriving from Roman centuriation and subpartition of rural areas: 4 long streets are oriented from north-east to south-west and other shorter roads, orthogonal to the former, delimit all built lots.

The lots are all rectangular in shape. In the north, where the oldest portion of the Village is located, lot sizes are smaller, whereas those in the more recent south portion are larger.

The elements that make the Villaggio Artigiano a privileged project area today derive mainly from two sets of issues: one of an urban, economic and social nature, related to the ongoing problems of the area, and the other linked to the context of the Villaggio Artigiano and its strong, untapped potential.

In a nutshell, the themes considered in the redevelopment plan are:
  • Identity value of the Villaggio Artigiano: it is a “piece” of the city history and an example of that “model Modena” that mainly contributed to the economic and social development of the city. For this reason, it is important, from the perspective of identity and business, to promote the renewal of the Village without compromising on its productive nature, and to boost the vitality of the area that seems to derive from the building typology and flexibility, which combines “home & shop” with very particular architectural languages.

  • Economic and entrepreneurial value: seen in retrospect, and with a modern perspective, Villaggio Artigiano was a major help in what today is called the start-up of new businesses. To this one should add, the opportunity for artisans to have their houses built in the vicinity of their workshop, thus reducing significantly their personal and family costs of residence and transport. This particularly applies to the early settlements

  • Urban planning value: with regards to urban design and urban planning, the Village, located next to the Old Town, but also well connected to the extra-urban transport axes, is a center of gravity as far as the redevelopment of the whole western sector of the city is concerned. This feature will be greatly enhanced by new road connections and new forms of public transport. In fact, the Village is highly affected by the planned diversion of the railway line bounding the area, which will leave a large “diagonal” line of interconnection to the city center for new public spaces and transport services.

These features make the Village an ideal testing ground from the point of view of urban sustainability through the recovery of the existing fabric, ground-saving oriented, and the increase in the functional mix.

One of the main goals of this redevelopment plan is to renew the buildings in the Village, by means of a deep restructuring of the existing edifices, respecting the size and volume relations among them and producing a new estate body, which carries on and updates the typical evolution process of the Villaggio Artigiano (Fig. 6.5).
Fig. 6.5

Villaggio Artigiano – Urban morphology

Therefore, the proposed regulatory actions are aimed at promoting the transformation of the Village, increasing the functional mix among production, which remains prevalent, services and residence, the latter to be rethought in new and experimental ways (home studio, new types of home-workshop, residential complexes with shared facilities etc.). In addition to these possible changes, on the public side, the main object of the redevelopment Plan is to redesign public spaces for meeting and socializing: rethinking and reorganizing the street mobility, creating parking areas and green spaces (using, for example, the large diagonal line on which the Village is grafted), signposting the presence of trade and services as an opportunity to generate significant spaces for urban quality of the neighborhood.

To date, the administration has launched a series of initiatives aimed at urban regeneration (buildings and public areas), as well as at economic and social improvement, summarized as follows:
  • new urban-building rules;

  • coordinated project for public space: the Village has its only public spaces in the streets, which have a very small section, are anonymous and not suitable for a non-automotive mobility. Through simulations and sectorial studies various options were examined for the transformation of the road network aimed to interconnect pedestrian, bicycle and automobile paths and to facilitate public accessibility and therefore the settlement of business and services.

  • to exploit the dis-used railroad area, to be reinvented as “gateways” to the Village, as a large walk urban connecting two parts of the city historically divided; the Village has indeed a well-defined urban morphology, which makes it easy to identify, but it’s also “closed” to the rest of the city (Fig. 6.6).
    Fig. 6.6

    Villaggio Artigiano – Planimetric view

Taking the modified environmental conditions of the area into consideration, the redevelopment plan aims to promote measures envisaging high-level performances, in order to ensure the environmental, as well as urban, upgrade of the area.

To counteract the alarming impact of UHI phenomenon the municipality of Modena began to consider the main environmental problems, to identify effective methods of construction.

The Plan aims to identify a synthesis of the main environmental issues related to the area of intervention, in order to derive a calculation method that can show the environmental performance achieved in the redevelopment of the individual lots.

The main environmental issues focalized in the Village are:
  • reduction of the Urban Heat Island

  • reduction of energy consumption

  • reduction of the hydraulic risk

The “Artisan Village Guidelines” summarize the main features of the environmental method prepared by the administration. It is worth stressing that there are various analyses still under way for the final validation of various technical and procedural issues; as a consequence, although the structural characteristics have already been defined, the approach implemented may still be modified or emended.

In any case, the following items were thoroughly considered:
  • Appropriate Building Massing:

  • Energy Efficiency

  • Passive strategies including: highly insulated; massing well arranged for summer radiation and also winter – optimized utilization of daylight,

Also using:
  • Buffer zones (such as winter gardens) to harvest passive solar energy and allow natural ventilation under cold/windy conditions

  • External solar shading

6.2.3 UHI Phenomenon in the Urban Area of Modena and Application of Models to Simulate Mitigation Measures

Analyses on the UHI phenomenon in the urban area of Modena have been performed with a focus on the summer season. We compared data from stations located within the urban area and from stations located in the rural area. The findings showed that minimum temperatures in the urban area were higher than in the rural one. The differences between urban and rural minimum temperatures were generally larger during spring and summer, when they reached values up to 6 °C. The highest intensities of urban heat island effect were found around midnight. On the other hand, the correlation between maximum values of temperature was the opposite: rural temperatures tend to be about 1 °C higher than the urban ones. Relevant positive trends were present in the 30-year time-series of temperature. Long term trend of Heating Degree Days (HDD) and Cooling Degree Days (CDD) were also analysed (Figs. 6.7 and 6.8). These parameters show to what extent the temporal trend of temperatures is either below (HDD) a predefined bioclimatic thresholds or above (CDD). A markedly decreasing trend was present in HDD time-series, while an opposite, less marked trend, appears for CDD.
Fig. 6.7

Long term trend of Heating Degree Days (HDD) for the urban and the rural area

Fig. 6.8

Long term trend of Cooling Degree Days (CDD) for the urban and the rural area

Two main simulation tools have been applied to the pilot area in order to estimate the effect of some mitigation measures from a quantitative point of view. These simulations were aimed at assessing the effects of types of mitigation actions, and not the effects of specific interventions.

The first model applied in the pilot area was RayMan, a simulation model able to calculate short- and long-wave radiation fluxes inside a complex urban environment. Output from RayMan model consists in the values of several thermal indices derived from human heat-balance model. RayMan calculates the mean radiant temperature using a simplified radiation balance applied to a person which is exposed to:
  • direct solar radiation;

  • long wave radiation from ground, building walls and vegetation

  • reflected radiation from the same surfaces.

In the present study, RayMan model was applied on a car parking area inside the Villaggio Artigiano. Firstly, the model was run for the actual situation in the domain (reference run) in a typical summer day in August. Then, some changes were introduced in the model domain (scenario runs) and the net effects of the mitigation measures on the thermal field and on the bio-meteorological conditions were estimated. A number of tests were carried out considering various combination of vegetation, type of materials for pavements and facades, height of buildings. From the point of view of thermal comfort, it was quite clear that most effective discomfort reductions were obtained introducing trees in the domain.

The shade from trees produced the largest impact and the mitigation effect was estimated in around 2 °C in the peak hours. A further point worth of notice is that, the pervious surface obtained by replacing the asphalt and/or concrete pavement with grass had a positive impact on the thermal comfort in its turn; however, the absolute value of this effect was much lower than in the scenario where trees were introduced, and the temperature reductions were below 0.5°. Modification of building heights showed rather small differences in the values of bio-climatic indices.

The second model used to simulate the impact of different scenarios was ENVI-met, a three dimensional, non-hydrostatic model of the atmosphere, based on the fundamental laws of fluid-dynamics and thermodynamics. ENVI-met is a much more complex model than Rayman and is able to simulate the tri-dimensional field of the usual meteorological variables taking into account the interaction between atmosphere, urban surfaces and vegetation characterizing the complex urban fabric.

The model domain was a square of 400 m × 400 m, about a half of the whole Villaggio Artigiano (Fig. 6.9). The horizontal resolution was 5 × 5 m (81 × 81 grid points). Vertical resolution was set to 3 m, with the exception of the first model layers, which were split into 4 additional layers with the aim of showing a better representation of the interaction between the atmosphere and the surface elements. The simulation were run for the typical summer conditions for the city of Modena. Various mitigation measures were considered: insertion of green elements (grass and trees), change of the albedo of walls, roofs and pavements, insertion of pervious surfaces in substitution of asphalt and pavements. The findings showed a well-defined ranking in the impact of mitigation measures (Fig. 6.10).
Fig. 6.9

Example of 2-m height field of temperature as simulated by ENVI-met model

Fig. 6.10

Vertical profiles of “all day” mean differences between each scenarios, labeled as indicated in the legend, and the control run

“Green courtyard with trees” was the most effective mitigation measure. A reduction of temperatures was evident for the entire course of the day. The “green roofs” scenario showed a peak of the cooling effect with respect to the control run at a height of around 10 m, with a slightly smaller impact at ground level. On the contrary, “cool roofs” and “pervious courtyard” scenarios showed a peak of cooling at ground level with a relevant decrease of the impact going upwards. On the other hand, scenario with “cool walls” showed a negative effect in terms of mitigation of urban heat island. The cooling effect induced in this scenario was possibly explained by the unsatisfactory consideration of heat balance in model equation for buildings.

6.2.4 Experimental Environmental Quality Index to Assess the UHI’s Mitigation Actions in a Building Lot

As described in the previews paragraphs, in the Villaggio Artigiano pilot area the following main environmental issues are taken into consideration:
  • reduction of the Urban Heat Island

  • reduction of energy consumption

  • reduction of the hydraulic risk (not strictly connected to UHI phenomenon)

Starting from the experiences carried out by other cities, the Municipality of Modena decided to create a new calculation methodology, to be tested in the redevelopment of the Village.

Several municipalities are already equipped with calculation methodologies, in order to highlight the environmental performance achieved by the redevelopment of urban lots.

These calculation methodologies, also known as “urban indexes”, are mainly focused on the urban impact created by the analysed phenomena, and are usually characterized by a simple algorithm.

The main existing urban indexes are the BAF, “Biotope Area Factor”, used in Berlin, Malmo and Seattle, and the RIE, “Reduction of the Building’s Impact”, used in Bolzano and Bologna.

Both indexes calculate the ecological value of an urban lot.

Unfortunately, these indexes have limitations which make their application to “Villaggio Artigiano” impossible.

The Biotope Area Factor considers only the “green” surfaces and is therefore not suitable to assess the positive effect of a “cold roof”.

The index of Reduction of the Building’s Impact considers only the horizontal surfaces and is therefore not suitable to assess the positive effect of a “green” wall.

The main goal of Modena Municipality was to create a calculation methodology capable to:
  • analyse all the surfaces that make up the urban lot, like the courtyard areas, building walls and roof,

  • analyse different types of surfaces, like green or cool surfaces,

  • stand up to existing indexes in terms of simplicity of data input,

  • make appropriate approximations, like urban indexes typically do,

  • highlight the environmental performance on the basis of indicators that predict physical tangible phenomena,

  • implement procedures and values already defined by laws or municipal regulations.

The three main environmental issues (reduction of the Urban Heat Island, reduction of energy consumption, reduction of the hydraulic risk) have been linked to two indicators that have been used to derive two indices, the index “RATE” of “reduction in the absorption of thermal energy” and the index “HYPER” of “reduction of hydraulic risk”.

The creation of the index “RATE” followed four stages:
  1. 1.

    a list of types of surfaces that include the typical materials of the existing context and the materials used today in new projects.

    Altogether 20 types of surfaces has been identified: 7 for the courtyard areas, 6 for the walls and 7 for the roofs. Some of these describe existing interventions, typical of the existing context, while others describe innovative interventions of recent use. The interventions that can be implemented in the courtyard areas are: garden or flower bed, tree or shrub, self-locking pavement, lawn driveway, “cold” asphalt, normal asphalt, gravel pavement.

    The interventions that can be implemented in the walls of the building are: green wall with frame on wall, green wall integrated into the wall, ventilated wall with frame on wall, light plaster, dark plaster, wall with exposed brick.

    The interventions that can be implemented on the roof of the building are: green roof, “cold” roof, tiled “cold” roof, photovoltaic roof, tiled roof, light flat roof, dark flat roof.

  2. 2.

    identifying a physical quantity, as an indicator, and a calculation methodology.

    The indicator chosen to estimate the index “rate” is the thermal energy absorption of each surface of the lot, due to the incident solar radiation.

    The absorption of thermal energy of a surface represents the amount of energy that that area is not able to reflect and disperse instantaneously, and therefore represents the amount of thermal energy that will be released for a certain period of time. The absorption of thermal energy is therefore able to highlight the capacity of a material to affect the Urban Heat Island.

    In order to calculate the absorption of thermal energy a formula is used, which correlates the technical and physical characteristics of a surface with the incident solar radiation.

    The technical and physical features used for the calculation of a generic surface, are: solar reflectance, emissivity and thermal resistance.

    The index “RATE” calculates the sum of the absorption of thermal energy of all surfaces that constitute the urban lot.

  3. 3.

    analysing the technical and physical features of every surface in the list and of the existing context, to estimate the indicator. For each of the 20 types of interventions, the respective values of solar reflectance, emissivity and thermal resistance have been estimated. As for walls and roof, different values of thermal resistance have been calculated, depending on the year of construction.

    To quantify the incident solar radiation, the values defined by the norm UNI 10349 are used. Municipality of Modena has obtained a value to be applied on the roof and different values to be applied to the walls, depending on their orientation. Regarding courtyard areas, an average value was estimated, taking into account the loss of energy caused by the shading by building volume.

  4. 4.

    adopting the typical/needed approximations of urban indexes.

The Artisan Village Guidelines “Feasibility study of environmental quality indexes to be applied to building lots”, made by Municipality of Modena, are attached in Appendix C and the link to the calculation software can be found on the website of the Municipality of Modena:and on the website of the Emilia-Romagna Region:

6.2.5 Adaptation Strategy to Heat Risk: Assessment of a Possible Development of the Heat Risk Alert System Based on the Use of Emergency Ambulance Data

Increased temperatures and extreme heat can lead to a rise in mortality. In EU countries, mortality is estimated to increase by 1–4 % for each one-degree rise in temperature, meaning that heat related mortality could rise by 30 000 deaths per year by the 2030s and 50 000–110 000 deaths per year by the 2080s.

As regard to the National level the Ministry of Health, in cooperation with the Ministry of Civil Protection, an “Early warning national system to prevent heat waves” has been operating since 2004, after the terrible summer of 2003. Furthermore, in 2005 a “National Operational Plan to prevent effects on human health from heat waves” was issued, and in 2006 “Guidelines to prepare monitoring plans in order to respond to heat waves” were provided to assist local authorities:

In coordination with national plan in Emilia-Romagna, a risk prevention local plan was designed and implemented to reduce the risk of damage and casualties due to summer heat waves.

Every year the plan guidelines are updated by the Emilia-Romagna Regional Government while ARPA (Regional Agency for Environmental Protection) issues forecasts throughout the summer.

The adaptation action then consists of:
  • Alert system managed by ARPA, alerting when temperature and humidity level raise above a risky threshold

  • Emilia-Romagna Regional Government coordination actions to assist most exposed people groups. Alert System

ARPA Emilia-Romagna has been endeavouring to provide forecasting systems of some environmental risk factors to local authorities for several years now. Among such factors, the prediction of heat waves has gained relevance, particularly in relation to climate change projections for the coming decades.

The heat waves forecast service has been operating since 2004. ARPA Emilia-Romagna manages a specific website platform:

The forecast service is active between 15 May and 15 September. The forecast is done with 72 h forewarning.

The Risk Alert alarm is based on the Thom’s Discomfort Index (DI). DI is a measure of the reaction of the human body to a combination of heat and humidity (Fig. 6.11).
Fig. 6.11

Thom’s discomfort index table

This index combines the values of humidity and temperature parameters to describe the conditions of physiological discomfort due to heat and humidity. The threshold of bioclimatic discomfort used for the Alert system were identified through a study of mortality conducted in the urban area of Bologna for the years 1989-2003.
  • Weak discomfort

    Weak discomfort conditions are defined when DI average daily value is 24. Under such conditions, the population feels discomfort but there are no increases in mortality.

  • Discomfort

    Discomfort conditions are defined when DI average daily value is 25. Under these conditions the weaker sections of the population, and especially the elderly, may experience health effects of various kinds, including headaches, dehydration. Such symptoms may cause fatalities in some extreme cases. The total mortality, natural causes and cardiovascular diseases increase on average by about 15 %, and mortality from respiratory causes up to 50 %.

  • Strong discomfort

    Strong discomfort conditions are defined when DI daily average value is 26 (the average daily index values never surpass this mark) or when an index level more or equal to 25 persists for 3 or more days. Under these conditions the categories of persons suffering from heat-related illnesses increase. The total mortality, natural causes and cardiovascular ailments, rise by an average of about 30 %. The mortality from respiratory causes raises of about 80 %.

Every day the system automatically alerts all concerned institutions (Healthcare District Services, Civil Protection…) via an email. The email states ALERT or NO ALERT in the object field, depending on if the DI is higher or equal to 24, or if it is lower than 24. Then the email itself specifies the Discomfort Level forecasted.

The following graphics show as an example the trend registered in 2012 and the one registered in the very hot summer in 2003 (Figs. 6.12 and 6.13).
Fig. 6.12

DI trend registered in 2012

Fig. 6.13

DI trend registered in 2003 Emilia-Romagna Regional Government Coordination Actions

Emilia-Romagna Regional Government coordinates actions to assist people groups who are most exposed to heat waves, through Health Care regional system, Civil Protection, non-profit sector. These actions are activated by the ARPA alert system and they include two main activities:
  1. 1.
    Home care assistance:
    • Set up and coordination of Local Networks of all the actors involved in home care assistance, i.e.: Local Health Authorities (AUSL), City Councils, Voluntary associations;

    • Map High Risk Groups to be monitored during Heat Waves Alert, i.e.:elder people [>75 Y/old] living alone at home (in particular Local Health Authorities are obliged to notify all cases of elder people discharged from hospital in summer period and living alone), disabled people;

    • To strengthen home care assistance services, using all possible collaborations with Civil Protection volunteers and non-profit associations active in welfare.

  2. 2.

    Information actions


It has been shown that information on potential threats can be extremely useful in preparing the public for adverse events, as well as facilitating the response when such events occur. Starting form this assumption, a strong effort has been dedicated to produce an effective communication to citizens regarding heat waves effect on health and practical suggestions to prevent heatstroke.

In particular specific information contents have been prepared on:
  • Heat effect on Health: direct effect (sunstroke, heatstroke, heat exhaustion, heat cramps), indirect effect (i.e. health condition worsening of people weakened by physical or psychological diseases), risk groups (elderly people, children, people affected by specific diseases – diabetes, cardiovascular disease…);

  • Practical suggestions to prevent Heatstroke: telling how to limit the discomfort (what to eat/drink and what not, most dangerous day time, how to dress, how to manage home air conditioning…); telling what to do in emergency case (symptoms, 1st aid, who to call…). All this information are spread out both through the specific web platform on Heatwave managed by ARPA ER ( and through specific awareness campaigns managed by Local Health Authorities, addressing the specific high risk groups. (i.e. leaflets have been created by local health governments and addressed to home care staff, informing them on what to do in case of heat waves, what to eat, how to dress, relation with medicines, how to behave at home and outside, early warning signs of a heat stroke). Proposed Pilot Action: Preliminary Assessment of a Possible Development of the Heat Risk Alert System Based on the Use of Emergency Ambulance Data

The suggested pilot action aims at verifying a possible improvement of the Heat Risk Alert System currently operational in the Emilia-Romagna region. The development would be based on the use of emergency ambulance data.

Today the discomfort index threshold levels have been identified via epidemiological analysis based on historical mortality data. A study developed by Arpa on all most important cities of the Emilia-Romagna region, except Rimini, evaluated the exposure–response curve of ambulance dispatches in relation to biometeorological conditions using time series techniques showing a strong correlation between ambulance dispatches increase and apparent temperature. The effects of high temperatures on health were evaluated for respiratory and cardiovascular diseases as well as for all non-traumatic conditions.

For apparent temperatures lower than 25 °C, ambulance dispatches were not affected by changes in biometeorological conditions. Above that threshold, an increase of ambulance dispatches associated with respiratory diseases has been found, while cardiovascular diseases remained unaffected by variations in apparent temperature. For apparent temperatures higher than 30 °C, the percent increases associated with each unit increment of apparent temperature became very high, with the main effect seen with cardiovascular diseases.

The findings of the study demonstrated the usefulness of ambulance dispatch data due to their strong link with heat and their real-time availability. As a matter of fact, these data are collected and stored with the same software and the same protocols across the region Emilia–Romagna, and are the only health data available in real-time.

Based on these reasons ARPA tried to test the possibility of the use of these data for a development of the heat risk alert system. The main goal of the analysis was to verify how strong was the relationship between bioclimatic discomfort conditions and increased ambulance dispatches across the Region on a daily basis.

ARPA defined as “alert day” a day when apparent temperature averaged among the main towns of the region is above 25 °C. The expected number of ambulance dispatches for each summer day was calculated averaging the daily ambulance dispatches in a 15-day period centered in the selected day over the years 2003-2006 (excluding all the alert days from the computation); a standard deviation was also computed as a variability indicator. Days with a number of ambulance dispatches exceeding the expected number for that day plus twice the standard deviation were considered as days with an elevated number of dispatches (“case day”).

The strength of the correlation between case and alert days was tested using sensitivity, specificity and positive predictive value defined as follows.

Sensitivity refers to the proportion of days showing elevated heat-related disease counts detected by the surveillance system during ON Alert Day - ONAD (reported cases correctly classified). Specificity refers to the proportion of days with normal numbers of heat-related diseases during Off Alert Day - OFAD. Positive predictive value (PPV) refers to the number of days with a significant count of ambulance dispatches during the ONAD among the total number of days with a significant count of heat-related ambulance dispatches. For example, a true positive is defined as the number of above-threshold days in terms of the number of ambulance dispatches during ONAD.

The fist results of our analysis were



IC95 %(0.14, 0.26)



IC95 % (0.92, 0.99)

Positive predictive value


IC95 % (0.76, 0.97)

These findings shows a correlation in terms of specificity and positive predictive value: in fact, almost every day in which an elevated number of ambulance dispatches occurred was an alert day, i.e. a hot day. In addition, the high value of specificity shows that almost no false positive are produced by the model. On the other hand, low sensitivity shows that a relevant fraction of alert days (i.e. hot days) doesn’t imply a large number of ambulance dispatches.

We also tested the calculation of the same indicators in single towns. The average value of sensitivity, specificity and positive predictive value obtained across the region were 0.13, 0.97, 0.83, respectively.

These preliminary results confirm the usefulness of a surveillance system based on ambulance data. An additional level of alert for the health prevention system would be suitable when alert days are associated with exceptionally elevated number of ambulance dispatches.

The most appropriate spatial scale for the alert system (e.g. single towns, “area vasta”, whole region), a more sophisticated definition of hot days (with the inclusion of information on persistence), alternative definition of threshold values for apparent temperature are currently under investigation. The forthcoming availability of longer time series of ambulance dispatch data will also improve the robustness of the analysis.

The use of Ambulance dispatches to evaluate the risks associated with biometeorological discomfort has the following advantages respect the current use of mortality data:
  • A higher number of data to correlate with Discomfort Index (10X), taking into account a wider range of the effect of heat on health.

  • The ability to monitor the effect on health during heat episodes (real time monitoring)

  • Additional information which can be gathered with ambulance dispatches (location of the calls) could allow spatial analysis to identify geographical areas at higher risk.

  • A better categorization of diseases in ambulance dispatches could enable to better define effect of heat waves in human health (cardiovascular diseases, respiratory diseases…)

In conclusion, the encouraging results of this preliminary analysis point to the setting-up of a surveillance system, whose actual implementation should be arranged in cooperation with Health Authorities both at local and regional level.

6.2.6 Conclusions

The UHI project sought to boost transnational discussion among policy makers, local administrators and professionals in order to bring about developing policies and actions with the purpose of adapting and mitigating the natural and man-made risks arising from the UHI phenomenon. For this purpose the pilot action of “Villaggio Artigiano” was aimed at:
  • providing a deeper knowledge on man-made risk of the UHI and its interactions with global climate change,

  • setting up suitable strategies for the mitigation of - and adaptation to UHI,

  • improving current land-use planning tools and civil management systems according to mitigation and adaptation strategies.

As explained above, the purpose of this case study was to find ways/rules that can mitigate and tackle the UHI phenomenon. Expected results are:
  • mitigation of UHI phenomenon through the definition of appropriate construction requirements and standards (green roofs, reflective materials etc..) in accordance with urban quality,

  • definition of guidelines to develop a specific project.

In this regard the Villaggio Artigiano is a suitable area to tackle UHI phenomenon, because it is part of a wider redevelopment context and regeneration process, strongly supported by public institutions and citizens.

The main objective of the regeneration plan is to allow a redevelopment of the housing stock in the Village, through a deep renewal of existing buildings, including demolition and reconstruction of a new building while maintaining the shape of the previous one, thus preserving the system of dimensional and volumetric relationships that characterizes the Village, and achieving a new building organism that continues and updates the typical evolutionary process of the “Villaggio Artigiano”.

Given the new environmental context in which the Village is included, the plan entails interventions aimed at fostering high-performance at the overall urban but also environmental systems.

For this purpose, the Municipality of Modena has defined a set of environmental indexes focused on the assessment of 3 main affecting phenomena: the Urban Heat Island, the energy requirements and the hydraulic risk. Consequently, a new calculation methodology has been defined, to be tested in the redevelopment of the Village, capable to measure the environmental effects and the achievement of the planning targets and to estimate the benefit-cost ratio in the redevelopment of urban lots.

Identifying indexes to measure the multiple environmental effects of the urban transformations is the challenge for urban planners.

6.3 Next Steps

The City of Modena is collaborating with the EELab Department of the University of Modena, to refine the scientific approach adopted in the analysis of phenomena.

Furthermore, Modena is collaborating with engineers from ARPA, the Regional Agency for Environmental Protection, within the European project UHI, in order to analyze the correlation between types of intervention described in the index “rate” and the reduction of the Urban Heat Island phenomenon

The Municipality of Modena is awaiting the conclusions from the ongoing analysis, to finally validate the experimental indexes and put them into practice.

The indexes, evaluating the achievement of valuable solutions from the environmental point of view, could be useful to set the potential reward to be given to requalification projects. The municipality is considering to provide the use of the indexes within the redevelopment plan of the Village, so to regulate rewards, through discount on the contribute for requalification, or through the introduction of “bonus” related to the architectural and urban value of the adopted interventions.

The urban indexes represent an experimental approach with huge potential, a starting point to give the planner flexible and easy to use instruments.


  1. 1.

    “The Biotope Area Factor as an Ecological Parameter” – Berlin, 1990.

  2. 2.

    Grabs Expert Paper 6 - The Green Space Factor and the Green Points System – 2011.

  3. 3.

    The project involves the following countries: Austria, Greece, Italy (Genoa, Catania), Lithuania, Netherlands, Slovakia, Sweden, United Kingdom.

  4. 4.

    “Manuale d’uso del foglio di lavoro Excel per il calcolo del RIE” – Comune di Bolzano – Ufficio Tutela dei Beni Ambientali.

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  6. 6.

    “SOLE – Stima Ombreggiamento Locale Edifici” – Dott. Ing. Giulio de Simone – Dipartimento di Ingegneria Meccanica – Università degli studi di Roma “Tor Vergata” – Excel file.

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Authors and Affiliations

  • Stefano Zauli Sajani
    • 1
    Email author
  • Stefano Marchesi
    • 1
  • Paolo Lauriola
    • 1
  • Rodica Tomozeiu
    • 1
  • Lucio Botarelli
    • 1
  • Giovanni Bonafè
    • 1
  • Graziella Guaragno
    • 2
  • Federica Fiumi
    • 2
  • Michele Zanelli
    • 3
  • Lodovico Gherardi
    • 4
  • Marcello Capucci
    • 5
  • Catia Rizzo
    • 6
  • Filippo Bonazzi
    • 7
  1. 1.ARPA Emilia-RomagnaBolognaItaly
  2. 2.Territorial Planning and Mountain Development ServiceEmilia Romagna RegionItaly
  3. 3.Urban Quality and Residencial Policy DepartmentEmilia Romagna RegionItaly
  4. 4.Territorial Cooperation Contact PointEmilia Romagna RegionItaly
  5. 5.Urban planning departmentModenaItaly
  6. 6.Urban Design and Transformation officeModenaItaly
  7. 7.Territorial Planning and Private Building officeModenaItaly

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