Would you like to learn more about the methodological approach taken to the development of the Urban Nature Atlas? 

On this page, you will be able to find details on how we view and define nature-based solutions, how the projects included in the database were selected, how the data was identified and reviewed.

Concepts and City Selection

Definition of nature-based solutions

The NATURVATION project defined nature-based solutions as deliberate interventions that can be inspired or supported by nature in addressing urban challenges, such as climate change mitigation, water management, land use and urban development (Bulkeley et al, 2017). These nature-based solutions can have a small scale such as pocket parks, community gardens or planting street trees, but they can also be large city-level projects such as the creation of a green corridor, a riverbank restoration or a city-wide biodiversity strategy that includes several green space elements.

Categorization of nature-based solutions

The Atlas distinguishes eight main types of nature-based solutions, including allotments and community gardens; blue areas; derelict areas; external building greens; green areas for water management; green indoor areas; grey infrastructures with green features and parks or semi-natural urban green areas. 

In most cases, identifying the type of the nature-based solutions is rather straightforward. For example, “Jardim das Oliveiras”, a green roof in Porto (Portugal) can be categorised as an “external building green” and be specified as “green roof”. However, nature-based solutions often belong to more than one urban setting and subdomain: as the development of a park can also include a creation of e.g. lakes (blue areas) or rain gardens (green areas for water management). 

Definition of sustainability challenges 

The NATURVATION project identified twelve challenges to which nature-based solutions can respond. Besides sustainable urban development, nature-based solutions can also address wider global development challenges, as defined by the UN Sustainable Development Goals (SDGs). The sustainability challenges, which were addressed by the studied nature-based solutions, were identified based on the specified project goals or implementation activities. The challenges could be chosen if the project description or a document presenting the project mentioned an objective that aimed to address a specific challenge. For example, if an urban park aimed to increase the quality of life and provide green recreational areas, we could conclude that the intervention is addressing the challenge of “health and well-being (in line with the SDG3). Search words for these challenges, in line with the relevant literature and the SDGs were provided to the data collectors in a Data Collection Guidance Manual.

Selection of cities included in the Urban Nature Atlas

During its creation, 100 European cities were included in the Atlas. A systematic approach was applied to select the 94 cities included in the survey, in addition to the project’s 6 partner cities (Barcelona, Győr, Leipzig, Newcastle, Malmö, and Utrecht). The aim was to select a city sample that ultimately represents the varied urban and environmental conditions across Europe and which has a broad geographical distribution. Applied indicators for the city selection included demographics, city size, unemployment, proportion of green space, access to green areas in Europe's cities, climate risk and vulnerability. By choosing a diverse sample of cities, the project aimed to analyse which types of nature-based solutions are being implemented, how they are being delivered and the issues they are seeking to address, what is their type, form, function and distribution.

UNA Cities

In order further expand the database, ​now cases from other cities are also included. 

Data Collection Process

Approach taken to the data collection

The original version of the database was developed between January and August 2017. As a first task (January to March 2017), the structure and attributes were developed and organized in a questionnaire format by the Central European University (CEU) and Ecologic Institute teams. The questionnaire was then tested in the NATURVATION partner cities and the database concept was finalized in April 2017. The technical design and testing of the web-based questionnaire took place in May 2017. 

The database was populated with data collected by 20 interns, drawn from the Master’s Programmes of CEU, Lund University and Utrecht University from June to Mid-August of 2017. Prior to the data collection, all interns took part in a one-day training based on the training manual developed by the CEU team. Data collection was supervised by the respective institutions for their own interns and had to pass a quality control by the project team at CEU. Data collection was completed by the end of August 2017. Data analysis and the development of the public database platform was launched in September 2017. 

By August of 2017, in total 997 questionnaires had been submitted and 976 processed for further analysis. In order to expand the Urban Nature Atlas to 1000 projects, additional nature-based solutions were included between July and September 2018. During this additional data collection, attention has been given to identify projects in cities with only 8-9 NBS in the Urban Nature Atlas and including nature-based solutions studied in the other Naturvation work streams (https://naturvation.eu/cities). 

During the months of June and November of 2020, a large database review process took place (please see Data Update), where the same data collection methods were applied.

Requirements for selecting nature-based solutions for the database

The data collectors were requested to identify up to 10 nature-based solutions per city, while aiming for a diversity of the selected interventions in terms of the urban setting where they take place, the sustainability challenges they address or the governance arrangements they employ.  Projects included in the Urban Nature Atlas had to fulfill the following criteria: 

  1. Address various urban societal challenges (e.g. climate mitigation, water management, coastal protection, human health and recreation, social justice); 
  2. Have function enhancing features, that change or enhance the function of an area/structure; 
  3. Use nature as an inspiration to address an urban problem was either a physical intervention or a discursive one. 

During the analysis of the collected data, certain examples of NBS were considered borderline cases and during a later evaluation stage, these cases were excluded from the final sample of European NBS. NBS interventions were considered marginal if they included primarily grey infrastructure elements; projects with controversial and potential negative impacts; projects without clear evidence on addressing urban societal challenges and projects without sufficient information on actual implementation. Some projects were excluded due to lack of information.

Method applied to the data collection process

The analysis of the identified nature-based solutions was based on secondary sources (e.g. project reports and other project documents, websites, news articles, research articles, studies and blog posts). The collected data was examined using discourse analysis. The intention was not simply to look for terms (e.g. nature-based solutions, green or blue infrastructure) but to search for patterns of discourse connected to those terms. Nevertheless, all answers reported in the database are based, without exception, on factual information with a reference.

Type of collected data

The collected data is submitted in a questionnaire format that contains seven sections and covers the following aspects: 

  • Section 1: General information including the location of the project, it’s timeline and a short overview of the project.
  • Section 2: Project objectives, targets, sustainability challenges that the projects aimed to address.
  • Section 3: Key characteristics including urban settings of the projects, ecosystem services delivered by the project, list of key beneficiaries and projects spatial scale.
  • Section 4: Governance and financing details, including details on the key actors and project initiators, policy drivers and enablers behind the projects implementation, and projects cost and financing sources.
  • Section 5: Type of innovation of the projects, as well as the novelty level and replicability of the projects.
  • Section 6: Evaluating and learning information, covering types of impacts found or expected to be found in connection to the studied projects, evidence of assessment and level of citizen involvement in the evaluation of the projects. 
  • Section 7: Data sources such as references and additional comments.

Identification of the addressed challenges, project beneficiaries and impacts

As the research was based on the analysis of secondary sources presenting specific nature-based solutions, the addressed challenges, the group of beneficiaries or the project impacts were also derived via a discourse analysis of the studied documents. With this approach, the research also considered the perceived or intended beneficiaries, challenges or impacts of nature-based solutions. 

Data Validation

Quality control process

During the first data collection in 2017, the collected data was verified in two stages. The first stage took place parallel to the data collection and submission, while the data collectors submitted the questionnaires (June and August 2017). Supervisors at CEU, Utrecht and Lund Universities checked all questionnaires for inconsistencies, questions that might have been forgotten, mistakes or incorrect input formats. After the data collection process was finished, specific questions were identified that could have a higher improvement potential. These were subject to further corrections by the database team at CEU. The second round of data quality check was completed in January 2018. 

For the database update in 2020, a similar approach was taken, with three supervisors at CEU responsible for overseeing the data collectors' work. Between June and November of 2020, the data collectors worked closely with their supervisors to complete the questionnaires, and the supervisors reviewed and corrected (when needed) all questionnaires. The data validation was a continuous task throughout the data collection and continued in December 2020.

Limitations of the data collection process and the applied methodology 

Project documents can be confidential, limiting access to the available information. In some cities, the identified nature-based solutions were limited to certain types (e.g. small-scale green infrastructure projects funded from participatory city budgets, allotment and community gardens) or had a generally weaker innovation level. 

Beyond limited data availability, some methodological issues also had to be tackled. The accuracy of the reported data was highly dependent on the referenced information. In order to ensure consistency across the data collected, information collected through direct contact (e.g. phone calls, interviews) was not included in the database unless a document containing the obtained data that could be referenced was available. Further limitations resulted from the time scale of the project and occasional language barriers. 

Database Update and Application

Database update process

Between June and November of 2020, all 1000 NBS projects included in the Atlas were updated and reviewed. This revision process was done by a large team led by CEU, that included: 3 supervisors and 14 data collectors.

In the new version of the questionnaire, attention was given to subjects and questions that emerged as important research topics since the original data collection in 2017. The updated questionnaire included both follow-up questions to original questions and new topics to be investigated. Besides answering new questions, the data originally reported in the database was reviewed to reflect the new developments with each cases since 2017 and to update any information sources, such as links not working in 2020.

Since May 2021, the databased was opened to submit new projects from across the globe. As a first step, international Naturvation case studies were included in the Atlas. To know more about how to create a user account and submit a new project go to the  Add a Project page.

Use of data 

The online version of the Urban Nature Atlas is intended as a resource for policymakers, practitioners, researchers and those with a general interest in NBS.

The excel version can be used to analyse the collected projects and identify general patterns (e.g. finance models, governance arrangements, stakeholder participation forms, impacts). The excel version of the database is intended for research users and can be requested from the project team.


If you would like to know some other particular details not covered on this page, please go to our frequently asked questions (FAQ) page.