Integrating macro-economic developments and land-use allocations in simulating urban dynamics

1. Integrating macro-economic developments and land-use allocations in simulating urban dynamics

2. Research context • Two research projects in New Zealand to develop and use spatial models for supporting planning processes • policy impact assessment • forecasting land-use developments • application to a rural region: Waikato • application to two urban regions: Auckland and Wellington

3. Land use change over time… • Land use dynamics are complex and exhibit self- organising behaviour • Planners and policy makers have a decisive influence on future land use Contradiction? Challenge!

4. Challenges • Simulation of spatial developments over time • Incorporation of a range of drivers • Dynamics driven by processes operating on various scales • Bottom-up and top-down interactions! • Development of a system for policy support • Useful system for policy analysts in supporting scenario studies and policy impact assessment • Transparent system with access to data and parameters for technicians and modellers

5. Starting point… • Metronamica land use model • Constrained cellular automata based model • Yearly time steps • Time horizon 2025-2050 • Spatial extent 100 x 100 km (Wellington) • Spatial resolution 100 m (Wellington)

6. Land use at time T+1 Land use & interaction weights Suitability & Transition Potentials Accessibility Zoning Stochastic perturbation & = & & Transition Rule Change cells to the land use for which they have the highest transition potential until regional demandsare met Time Loop

7. How to obtain regional demands? • Macro-economic model • Input-output model • Calculation of economic developments per sector taking into account the interdependencies between sectors • Annual time step • Demographic model • Age cohort model • Calculation of the population per age cohort based on birth, mortality and migration rates • Annual time step

8. Integrating socio-economics and land use Supply side Demand side t-1 - Exports - … Change in final demand ($) Final demand ($) Demographic developments Reduction in output ($) Output ($) Conversion to land use demands (ha) Land use allocation Land that could not be allocated - Spatial planning- Suitability - …

9. Integrating macro-economics and land use • Main benefit of using IO (or CGE) models is that the impact of land use can be analysed not only on one sector, but also on all other sectors • Dynamic coupling between macro-economics and land-use change • Impact of socio-economic growth on land use developments • Impact of (limited) natural resources on economic development • The concept of the economic model had to be stretched by calculating the demand in one year and the supply in another, not allowing an equilibrium in each year

10. Conclusions on the modelling approach • Dynamic coupling between macro-economics and land use change • Impact of socio-economic growth on land use developments • Impact of (limited) natural resources on economic development • Equilibrium approach of economic models often poses conceptual conflicts with the simulation approach of dynamic land use change models • Being able to couple models technically doesn’t mean the coupling makes sense! • For future research it is recommended to focus first on the integration of the processes and next on the model implementation

11. Thank you! hvdelden@riks.nl