Population Impact Assessment
Climate change is impacting and will continue to impact the European continent, leading to more frequent heat waves and extreme colds, floods, storms and draughts. In this context, it is even more important for urban residents, city authorities, national and EU institutions to receive information about how they will be affected and to plan accordingly. To do so, exact measurements on where the population is and how they are exposed to these threats are needed.
Today, most European cities have information on the population distribution and density available. Such information are mostly based on statistical census data. However, as these data are collected at various administrative levels (commune or district), they are often too coarse for a detailed analysis. Thus, additional information is needed to refine the datasets.
Within the DECUMANUS project, GeoVille uses freely available EO-based land cover and land use data (Basic Service) and locally-provided data from the cities (Premium Service) to refine this census information to better reflect the reality in terms of the spatial distribution of the population. Knowing e.g. the type of urban fabric (residential or non-residential) or the number of commuters and work places can allow for very detailed population estimates at night- and during day-time.
In a second step such spatial aggregated population data can then be used to assess the exposure of people to different climate and environmental threats.
>> Night-time population distribution and impact assessment based on freely available EO-based land cover and land use data (resolution: 200 m)
>> Day-time population distribution and impact assessment based on locally-provided data (resolution: building block or district level)
User feedback and usability
With the developed services, city planners can get a better understanding of where people are located in the night- and day-time, what the scale of the commuting is in reality and where the biggest agglomerations of people are. Thus, city planners can derive new information on the number of population exposed to climatic impacts such as bad air quality, floods, storm waters, heatwaves and sea level rise. The information can then be used to support effective climate change adaptation and mitigation.
Beyond the scope of the project, the service can furthermore be used for traffic or public transport planning, geo-marketing, the creation of emergency/evacuation plans or the calculation of health effects on the population e.g. on street level. Additionally, depending on data availability, demographic data can be used to further refine these datasets allowing for the division of e.g. age groups to focus on elderly or children.
”Alongside the regular census data, the day-time population product created by GeoVille gives the city officials and other actors of the Helsinki Metropolitan Area new insight into urban planning. The innovative dataset may be used e.g. in the planning of climate change adaptation measures or air quality improvements. Given the challenging initial data gathering and limited coverage, GeoVille has achieved well in producing plausible new information about day-time population agglomerations.” (Johannes Lounasheimo, Climate Specialist, HSY)
Example Premium/Local Products:
The DECUMANUS Premium Service analyses the impact of climate change scenarios to the day-time population in high resolution (building block level). The day-time population refers thereby to the number of people who are present in an area during normal business hours. The calculation is based on a variety of locally-provided input data such as commuting data, work places, universities and schools. The results are ready-to-use, easy-to-understand visualisations of the day-time population distribution which are web accessible and delivered in GIS ready formats. As for the Basic Service, the results are then further combined with information on environmental threats and climate change risks such as flood risk datasets or outcomes of urban climate models to derive the exposure of the population (see example). The aim of the service is to address specific problems in European cities and develop, based on the results, better and advanced adaption strategies.
Example Basic/Strategic Products:
The focus of the DECUMANUS Basic Service is to analyse the impact of climate change scenarios on the night-time (residential) population in a resolution of 200 m. The service uses statistical census data in combination with freely available EO-based land use and sealing density information (Urban Atlas & High Resolution Imperviousness Layer) as the basis for the disaggregation modelling. The results are ready-to-use, easy-to-understand visualisations of the night-time population distribution which are web accessible and delivered in GIS ready formats. For the impact assessment the results are then further combined with information on environmental threats and climate risks to derive information on the exposure of the population. The aim of the service is to provide comparable information layers for rankings across different cities on a European-wide scale.
Night-time (residential) population disaggregation in London based on official census population data combined with LULC data.