Horizon CDT Research Highlights

Research Highlights

Modelling Urban Resilience and Sustainability as a Complex Socio-technical System

  Chenyan Zhang (2014 cohort)   www.nottingham.ac.uk/~psxcz5

Cities are increasingly being recognised as sites of resilience and sustainability, as centres of innovation, as testbeds of technologies, and as indicators of quality of life and services. Mounting pressure of population growth and abuse and misuse of technologies on resource consumption, carbon emissions, biodiversity and land use change shows that cities are the pattern makers or breakers of many of the unsustainable trends which push the planet beyond its ecological boundaries (Alberti 1999). Note that the built environment does not just comprise buildings, infrastructure and transport therefore; it includes human community, cultural experiences and interaction of people (NZ Ministry for Environment, 2009).

A social-technical system stresses on the reciprocal relationship between human and machine by considering the human factors, the mental, behavioural and social conditions of human in the organisational and technical framework of production. It’s a co-design and co-evolution of both the social and the technical system. Applied to the urban arena, the urban inhabitants and their activities are an indispensable part of the everyday operation of the city. Cities as complex systems are made of at least two sub-systems (Hillier, 2009): a physical sub-system, made up of buildings linked by streets, roads and infrastructure, and a human sub-system made up of movement, interaction and activity. Thus, cities can be thought of as social-technical systems. A social-technical approach to model urban resilience and sustainability has several advantages:

First, cities are intrinsically vulnerable and unstable entities (Amin, 2014). Being large, open, dispersed and constantly evolving systems, they are full of variety, latency and multiplicity. They are nodes of multiple networks which affect resource allocation, ecological security, and activity patterns. The complexity and dynamics of cities allow researchers to employ systems thinking to tackle many of their burning issues.

Second, urban issues entail two layers of problem-solving. At first glance, they are technical problems. For instance the topological or spatial organisation of cities as the technical system can be analysed by ways such as algorithmic analysis of maps, e.g., the density or clusters of population, the shortest path between places, the optimisation of the logistics or transportation systems, etc., but more importantly, a deeper understanding of cities reveals that they are essentially social problems -- the social system design involves the understanding of the dynamics of human cognition, particularly when mobilising large groups of people. How the spatial configuration of the cities defines and organises human activities and how human activities reshape the outlook of cities are complex and dynamic interactions of the technical system and the social system.

Third, cities are complex social-technical systems which possess self-organisation and self-regeneration capabilities. These organic properties are at the heart of studying complexity paradigm. Complexity science may be described as the science of learning systems, where learning is understood in terms of the adaptive behaviours of phenomena that arise in the interactions of multiple agents (Davis & Simmt, 2003). Thus it is a fitting apparatus to study cities as complex social-technical systems by ways of complexity science and agent-based modelling.


Alberti, M. (1999). Urban patterns and environmental performance: What do we know? Journal of Planning Education and Research 19(2): 151–163.

Amin, A. (2014). Epilogue: The Machinery of Urban Resilience. Soc. Sci. 2014, 3, 308–313

Davis, B & Simmt, E. (2003). Understanding learning systems: Mathematics education and complexity science. Journal for Research in Mathematics Education, Vol. 34, No. 2, 137-167.

Hillier, B. (2009). The city as a socio-technical system: a spatial reformulation in the light of the levels problem and the parallel problem. Ketnote paper to the Conference on Spatial Information Theory

NZ Ministry for the Environment (2009) Rethinking Our Built Environment: Towards a Sustainable Future. New Zealand Government

This work was carried out at the International Doctoral Innovation Centre (IDIC). The authors acknowledge the financial support from Ningbo Education Bureau, Ningbo Science and Technology Bureau, China's MOST, and the University of Nottingham. The work is also partially supported by EPSRC grant no EP/L015463/1.