Intra-city Metabolism of 10 Major Cities in England

LMTThe UK has one of the world most urbanised societies where nearly 83% of the total population lives in cities. The continuing population growth could lead to increases in environmental pollutions and congestion within cities. Urban metabolism proposes an analogy between cities and ecosystems to study the metabolic processes within complex urban system akin to natural biological system. It remains as a challenge to fully understand the complicated distribution of resource flows within an urban network.

In this project, Ecological Network Analysis was performed onto 10 major cities in England (i.e. London, Birmingham, Manchester, Leeds, Liverpool, Newcastle, Sheffield, Bristol, Nottingham and Southampton) with the intra-city monetary flows between all economic sectors to investigate their respective metabolic relationships. The classification of economic activities in all cities:

1. Agriculture, Forestry and Fishing

2. Production other than manufacturing

3. Manufacturing

4. Construction

5. Distribution

6. Information and Communication

7. Financial and Insurance Activities

8. Real Estate Activities

9. Business Service Activities

10. Public Administration

11. Other activities

Based on the connections between the sectors, the types of relationship identified:

  • Mutualistic: Both sectors receive positive benefits from each other.
  • Exploitative: One sector benefits while the other sector suffers - being exploited.
  • Competitive: Both sectors suffer negative influence.

The overall status of each city was expressed using Mutualisn and Synergism indices.

  • Mutualism Index, M: Ratio of number of positive utilities to negative utilities (Healthy if M > 1 when there are more positive utilities than negative utilities)
  • Synergism Index, S: Ratio of sum of all positive utilities to sum of all negative utilities

Exploitative behaviours were observed in most cities with an average mutualism index of 1.03 and synergism index of 3.39, with London being the most mutual and Liverpool the least. Bristol ranked the highest in terms of synergism index while Leeds had the lowest. The results suggest that London has the most developed metabolic system among those cities. This work provides an insight to the wide range of ecological metabolic characteristics observed within the targeted cities which can potentially expand to a multi-scale assessment of urban metabolism across the country.