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Urban Circularity Assessment


Domestic Extraction (DE) of biomass, minerals (metallic and non-metallic), as well as fossil fuels plays a minor role in Apeldoorn as can be observed in the Sankey diagram. Local extraction is limited to biomass materials.

As metal ores and fossil fuel extraction is minimal or non-existent for the Netherlands, no extraction was expected for Apeldoorn. In terms of non-metallic minerals, salt, limestone and gypsum, clays and kaolin, sand and gravel were extracted in the Netherlands for at least 10 years, although none of those were extracted in Apeldoorn.

The biomass extracted locally were 225,833.6 tonnes in 2018 and 248,821.8 tonnes in 2014, which represents a decrease of 9%. Overall, fodder crops and grazed biomass dominated this material group by far (see chart). Grazed biomass (184,568.5 tonnes in 2018) is the material that the 42,513 grazing animals, cattle (95% of animals), sheep, goats, and horses were consuming in Apeldoorn (2018). They ate about 80% of the total biomass in both years and consumed an additional 14-19% of the rest in the form of fodder crops.

The rest of the biomass extracted is marginal and represented a total of 9,308 tonnes or 4% in 2018. Potatoes and sugar beets made up more than half of it. This comes as little surprise considering that only 167 ha, 3.41% of the cultural land was used for arable farming and horticulture. An “honourable mention” should be made of the Stadsakker, an initiative that owns and cultivates a 2.5 ha field to bring fruits, vegetables and education around local food production to Apeldoorn. Since their annual production was unknown and the land very small, they were not included in the analysis.

Lastly, it was reported from the municipality that there are several timber companies in the city as well. Upon further investigation, most of them seem to be wholesalers or retailers and the Nederlandse Rondhout Combinatie B.V., a large local roundwood company, does not harvest timber in the municipality.


The EU Horizon 2020 funded CityLoops project focuses on closing the material loops of cities in terms of material flows, societal needs and employment. Cities, depending on their magnitude and types of economic activities, possess considerable opportunities and various levers to transform their metabolism and economy towards a more environmentally sustainable and circular state.

Within this project, seven European cities, amongst those also the city of Sevilla are (planning to) implement demonstration actions to kickstart their circularity journey. To better understand what the current circularity status quo is, as well as the impact of these actions, and the efforts needed to transform their cities, an Urban Circularity Assessment (UCA) method was developed. The method consists of urban material flow and stock accounting that paired with system-wide indicators assesses the material circularity of a city.

The material flows are accounted economy-wide for two separate years, applying a city-level adjusted Mayer et al. (2019) framework, which in itself builds on the EW-MFA method, including a wide material scope (specified below), while optimised for a circular economy assessment. The material stock accounting is limited to the buildings of the municipality, with the exact material scope depending on data availability in each city. Finally, the mass-based, “circularity” indicators cover the entire system and enable the assessment of a city’s circularity. As such, a balance between comprehensiveness and scientific rigour on the one hand, and operability by urban policy makers and practitioners on the other is sought by the UCA method.

The material scope of the flow accounting aims to cover the entire local economy and is divided into a total of six material groups. These material groups are depicted as icons here and were studied each with more specific materials in sub-categories and along the supply chain of domestic extraction, imports & exports, domestic material consumption and waste. When studying these materials and the entire supply chain, together, these elements help to set a solid knowledge and analytical foundation to develop future circularity roadmaps and action plans.

MF1 - Biomass
MF2 - Metal ores (gross ores)
MF3 - Non-metallic minerals
MF4 - Fossil energy materials/carriers
MF5 - Other products
MF6 - Waste for final treatment and disposal

Within the CityLoops project, the Urban Circularity Assessment was carried out by three of the seven cities (Mikkeli, Porto and Sevilla) themselves after having previously successfully completed their Sector-wide Circularity Assessments and Reports. They could build on extensive training that they had received in the form of courses on data collection for the construction and biomass sectors and data processing. The cities were accompanied and supported in their work by the Metabolism of Cities team, who conducted the UCA for two further cities (Apeldoorn and Bodø). Numerous additional insights can be found in the individual Data Hubs of each city.

This current Urban Circularity Assessment report presents the gathered information in seven sections:

  • Urban Context
  • Economic Context of Sevilla
  • Material Flows in Sevilla
  • Material Stock in Sevilla
  • Analysis of Flows and Stocks: Measuring Indicators
  • Data Quality Assessment
  • Analysis of Data and Indicators: Assessing Circularity

It provides contextual information of the city and the local economy under study. It then illustrates the quantities of flows in the single parts of the supply chain, summarised by a Sankey diagram, followed by a map of the material stock. Both of the accounted materials are evaluated in the form of circularity indicators and their data quality. Finally, the results are analysed and interpreted to determine a status quo, taking into account limitations of the data used, before recommendations are offered on how to achieve greater material circularity in the municipality of Sevilla.

(* The italic texts in this report were written by Metabolism of Cities' Aristide Athanassiadis and Carolin Bellstedt. They provide relevant general information and serve as connecting elements of the single report parts.)

Urban Context

To contextualise the results of the Urban Circularity Assessment, this section provides population and land use information data for Sevilla. In addition, population numbers and area size of the city under study, as well as its corresponding NUTS3, NUTS2 and country were included, as can be seen to the right of the Sevilla map. Data for these scales were added to better understand how relevant and important the approximations are when downscaling data from these scales to the city level.

1,324 km2
1,234 km2
1,234 km2
1,234 km2

Population of Sevilla

Briefly describe how the population developed over time

Data source

Land use

Data source

dominant types of land use

Economic Context of Sevilla

This section puts into perspective the economic context of the city under study. It describes its significance in terms of GDP or GVA and provides information on the number of people employed, as well as the main economic activities. Main actors that play a significant importance may also be highlighted.

GDP (monetary value, in €) Employees
Sevilla 324 1,324
Sevilla 1,234 1,234
Andalucía 1,234 2,134
Spain 1,324 1,234

The economic activities in Sevilla

economic activities

Material Flows in Sevilla

Measuring material flows and circularity is a data heavy exercise. Numerous datasets were collected and visualised throughout the Urban Circularity Assessment process. To synthesise these findings, a Sankey diagram illustrates how material flows of the local economy of Sevilla are circulating from one lifecycle stage to another. The height of each line is proportional to the weight of the flow. This diagram therefore helps to quickly have an overview of all the materials flows that compose the economy and their respective shares. The flows that are coloured in light blue in the Sankey diagram, are return flows. This means that they flow in the opposite direction of the lifecycle stages and are subjected to reuse, redistribution, or remanufacturing. Their size relative to the others is a good indication for a materials' circularity.

Data source

13 Imports & Exports

and then some more

14 Domestic Material Consumption

15 Waste

Material stock in Sevilla

Determining and analysing the material stock of a city can, similarly to the material flow accounting, also be a data intensive endeavour. The intensity depends on the scope and the data availability. For the Urban Circularity Assessment, the scope includes all residential and non-residential buildings in the municipality. Unlike for the material flow quantification, the analysis is not done for one or several specific reference years, but considers all buildings that have been constructed and still exist, up until and including 2022 (year of study). The aim is to quantify the materials that every single building contains and represent them spatially on a map. Depending on the data availability around building typologies, age cohorts, building height and material intensities, different, specific quantifications and investigations can be made.

The embedded map allows to explore the building stock of Sevilla and interact with the different scales and buildings by zooming in and out, and clicking on the buildings to discover more about typologies and quantity of building materials. The widgets on the right can be used to account for certain information, e.g. the number of buildings in an area, or to filter for specific construction years, which in combination with the average useful life of buildings can be used to calculate the potential urban mine. Furthermore, an analysis can also be performed by using the lasso tool and drawing an area (a block, a neighbourhood or an urban area) to be analysed.

An essential component material stock of buildings in Apeldoorn is building typologies (more detail is provided in the next section). To define them the following pieces of information are needed: building footprints of all buildings (ideally geo-spatialised) as well as their land use, age, height and gross floor area. These pieces of information were provided by the Dutch Kadaster (add ref).

While traditionally the typologies are defined directly through this dataset and then material intensities are measured, in the case of The Netherlands, a very relevant database on Dutch material intensities was already available (Sprecher et al. 2022). As such, in this specific case, the building typologies were developed to fit the ones already available in the material intensity database. Seven main building typologies were defined:

  • Residential row house (when the function of the cadaster is 'Woonfunctie', the building ‘touches’ another one; and is below 6 storeys)
  • Residential single house (when the function of the cadaster is 'Woonfunctie', the building ‘does not touch’ another one; and is below 6 storeys)
  • Residential apartment building (when the function of the cadaster is 'Woonfunctie', the building ‘does not touch’ another one; and is below 6 storeys)
  • Residential high rise building (when the function of the cadaster is 'Woonfunctie', the building ‘does not touch’ another one; and is above 6 storeys)
  • Commercial (when the function of the cadaster is 'Winkelfunctie')
  • Office (when the function of the cadaster is 'Kantoorfunctie')
  • Other (when the function of the cadaster is 'Overige Gebruiksfunctie', 'Gezondheidszorgfunctie', 'Industriefunctie', 'Sportfunctie', 'Onderwijsfunctie', 'Logiesfunctie')

The pie chart here illustrates the share of each typology in the total building stock.

18 Analysis of Material Stock

Analysis of Flows and Stocks: Measuring Indicators

To monitor the progress of the local economy towards circularity, a number of indicators were proposed and measured. Altogether, these indicators depict several facets of circularity of the sector. As such, they need to be considered in combination rather than in isolation when assessing circularity. In addition, these indicators can be compared to other cities or spatial scales (such as the country level). However, this has to be done with great care and use of the contextual elements in the previous sections of the report. Finally, the value measured from these indicators can be traced over time to track the city’s progress towards circularity. The below table provides the value for two reference years, where possible, and the percentage change between the two.

Insert the table with indicators

Describe the indicators that were chosen and their development over time

Data Quality Assessment

Numerous datasets were collected and considered in the Urban Circularity Assessment and this section qualitatively assesses how reliable the data used is. In some cases, datasets were not available for some materials or for some lifecycle stages for the city. Therefore, estimations needed to be done by looking at data at higher spatial scales (region or country) and downscaling it with proxies, described in the part on data gaps and assumptions.

The overall data quality is considered as well and depicted in the data quality matrix below. It is expressed through four data quality dimensions: reliability, completeness, temporal correlation, and spatial correlation. Each dimension has its own criteria for the ranking of high (green), medium (yellow) and low (red), which is based on this Pedigree report and shown in the table here. There may be additional explanations in some cells, as supporting information.

Rating Reliability Completeness Temporal correlation Spatial correlation
high Reviewed or measured data Data exists for all of the single sub-material groups and/or materials 1 data less than 3 years difference to the time period of the data set City-level data
medium Estimated data Data exists for most of the single sub-material groups and/or materials 2 data less than 6 years difference to the time period of the data set Regional-level data (NUTS 3)
low Provisional data Data exists for the main material group only 3 data less than 10 years difference to the time period of the data set NUTS 2 and country-level data

Matrix based on the data quality matrix

Couple of paragraphs that explain the data quality

Couple of paragraphs that explain the gaps and in general how they were closed (sources, assumptions, calculations

Analysis of Data and Indicators: Assessing Circularity

This last section of the UCA report analyses the status quo in terms of material circularity in Sevilla. It takes into account the findings visualised in the (Sankey) diagrams and the conclusions from the indicators. The overall results of the Urban Circularity Assessment are discussed and interpreted here, before providing recommendations to accelerate the transition towards a more circular Sevilla.

Insights on status quo of Sevilla

Recommendations for making the city more circular