Satellite technology to monitor and fight against climate change in cities: urban heat islands
Urbanization and climate change are increasingly interconnected, with metropolises and cities often affected by heat waves and storms – extreme weather events that typical cityscapes amplify with significant effects on their populations. With this in mind, architects and engineers are experimenting with new interpretations of the relationship between people, cities and nature by developing sustainable infrastructure, in accordance with the Sustainable Development Goals (SDGs) of the United Nations 2030 Agenda. In this case, SDG 9 – Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation.
Milan, Italy. Image WorldView-2 © DigitalGlobe (2020)
This month’s photo is a very high resolution photo of Milan’s business district, complete with Piazza Gae Aulenti and the vertical forest. It is a territory designed with sustainability in mind, rich in biodiversity, green spaces and bodies of water, which makes us reflect on how the increasing attention paid to the climate and the environment more and more influence on urban projects.
Space technology is making an important contribution to monitoring this phenomenon through international programs focused on the region. Leonardo plays an important role in these initiatives through the manufacture of satellites alongside Thales Alenia Space, in data acquisition, services and applications with Telespazio and e-GEOS, and by developing sensors – the “eyes” satellites – many of which are created in laboratories. Cultivating the potential of space technologies to support sustainable development is one of the pillars of the company Be tomorrow – Leonardo 2030 strategic plan and is part of our overall sustainable development plan.
We spoke to Monica Palandri, project manager at the e-GEOS Geographic Information Center to find out more.
What can satellites do to monitor and counter extreme weather events at the urban level, while promoting the development of sustainable infrastructure?
e-GEOS has carried out several studies and projects related to climate change – from the melting of glaciers, to the reduction of available water resources, to the assessment of the increase in desertification. These phenomena, which often overlap, occur quickly and are therefore difficult to manage. Designing new urban spaces taking these factors into account is not easy, even in the face of a constantly growing urban population. Among the most interesting projects on which e-GEOS has worked is the identification of the hottest urban areas – the “heat islands” – in support of the city of Milan. During the summer, a 4 to 5 day heat wave period, satellite data has enabled e-GEOS to map the neighborhoods and areas most exposed to these phenomena, which can be five degrees warmer than other areas of the region. This data is obtained directly from NASA and ESA satellites, such as Sentinel 3, which, when integrated with satellite data at a higher resolution (30 meters), allows us to estimate temperature measurements. at the sub-district level thanks to downscaling algorithms. Once the heat island maps have been defined, geoinformation tools are superimposed on the vulnerability maps of urban centers which indicate, for example, the presence of children under 10 or people over 70. With this image available, the public administration can develop solutions, encouraging the implementation of sustainable infrastructure such as green roofs, vertical gardens and water structures such as ponds and lakes that help to lower the temperatures. These natural solutions also have additional positive impacts; Being made from plant-based materials, they increase soil permeability, improve water capacity, and dampen runoff to counter flooding. This capacity has, however, been reduced over the years due to land use, especially in urban areas.
What are the advantages of e-GEOS services?
Satellite data provided by e-GEOS can be superimposed on public administration maps. The maps, which are constantly updated, provide very useful information for those involved in town planning and the design of public spaces, thanks to the information that is integrated into the data collected by the sensors in situ. This gives town planners the ability to define the planning of all green spaces.
This data is also important for Civil Protection during extreme weather conditions, allowing them to organize immediate responses during heat waves, to establish how and where to intervene, as well as to pre-alert nearby hospitals.
What are the additional applications of the platform?
Once the design and implementation of sustainable and resilient infrastructure within urban spaces is completed, we can monitor and assess the benefit provided by these new urban typologies. For example, in the case of the business district of Milan, we can predict the level of temperature drop in this area compared to its previous conformation. These evaluations can also be extended to measure the quality of the territory or to other parameters, to provide local authorities and public planners with the data and tools necessary for decision-making, while taking into account all the factors of interaction of the territory.
For example, e-GEOS recently concluded the Life METRO ADAPT project – climate change adaptation strategies and measures in the metropolitan city of Milan. This project is now in the reporting phase with the European Community, which has expressed great satisfaction with the results obtained. In addition to having adopted maps to monitor heatwaves, vulnerability, hazard and risk, e-GEOS undertook a study of the variation in the decrease in green indices due to the increase in temperature in the areas. of the Parco Sud in Milan. The city used this valuable information to develop the Metropolitan Territorial Plan which was adopted in July 2021.
Other relevant studies were also carried out in Rome with the help of the Italian environmental association Legambiente. In this case, data from Copernicus (Sentinel-3) was used to identify a synthetic heat island map. In one of the hottest neighborhoods, we were able to identify intervention priorities. This analysis is useful for planning where to focus investments and / or incentives to get the most out of the redevelopment (town planning offices, businesses, individuals, etc.).
To learn more about Earth observation technologies and solutions, visit other interviews.
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