The Integrated Scenarios Explorer ‘ISE’ [3]
Demographic Change
Agenda
•
13.30 – 14.00 Demographic Model•
14.00 – 14.45 Discussion on Wellington Region Demographic Changes•
14.45 – 15.00 Afternoon Tea•
15.00 – 16.00 Modelling Demographic Changes in ISETentative Only, Ask Questions
Wellington population changes
Sustainable pathways 2
•
2009 to 2015 MBIE funded research programme focused on achieving sustainable urban futures ($3.8 million over 6 years)•
Builds on previous ‘Sustainable Pathways’ (2003-9) and ‘Creating Futures’ (2006-10) programmes•
Collaborative policy-science research programmeSustainable pathways 2
•
Mediated Modelling (Assoc Prof Marjan van den Belt).Stakeholders directly engaged in formulating and building models.
Reduces gap between model builders and end-users.
•
Spatial Dynamic Modelling (Dr Garry McDonald). Enables end- users to simulate visually future implications. Integrates socio- economic, environmental, land use, and transport models into a spatially explicit and dynamic computer model.•
Embedding into Council Processes (Melanie Thornton GW, Regan Solomon AC and Dr Beat Huser WRC). Reduces gap between model building capacity and use of models. An end-user led objective.What is ISE?
Society Economy
Environment
ResourcesWastes Goods
Labour
Services
Stewardship
Spatially-Explicit Multi-scale
Dynamic
ISE integrated sub-modules
Simulating policy options
Value of a policy relevant indicator
• Problem identification
• Design of solutions
• Exploration of solutions
Policy
intervention
External event
Policy
intervention
External event Policy
intervention
• Analysis
• Evaluation
• Selection
• Authorization
Alternative 1 Alternative 2 Alternative 3 GOAL
Alternative 4 Alternative 5 Alternative 6
PAST PRESENT FUTURE
• Recognition
• Diagnosis
Demographic model
•
Single year age-sexcohort model for region
•
SNZ Sub-national population forecasts (yet to be completed)•
Fertility, mortality, net migration, average life expectancy & people living in each land use categorySetting up demographics
Setting up: External factors
Setting up: Policy measures
Setting up: Expert Interface
Cell and area population projections
The population in each cell, and any other aggregated area, including TAs may be crudely calculated using the table to the right, cell counts and population densities for various land uses
Land use % at time
t Residential – low density 9.0 Residential – medium
density
42.7 Residential – high density 2.7
Other 45.6
TOTAL 100.0
Demographics drives change!
Demand side
Final
demand ($)
Output ($)
Supply side
Change in final demand ($)
Reduction in output ($)
Land use allocation
- Spatial planning - Suitability
- … t-1
Land that could not be allocated
Conversion to land use demands (ha) Demographics
- Exports - GFKF
Demographics drives change
• Determines residential land use (low density, medium density, high density)
• Determines labour force availability and, partially, requirements
• Domestic demand for goods and services produced by the economy
• Determines external infrastructure inputs such as roads,
airports, ports and so on
Activity based approach
Conceptual
• Model activity and land use separately
• Land use and activities are mutually influential
• More than one activity in one location
Technical
• Activities and land uses are updated every step in all cells
• Constrained only in terms of activities
• Builds on existing Cellular Automata model
Activity based approach
• Lattice of cells
• Agents are represented locally by their activities
• Agents interact with the landscape
• Agents interact with each other
• No individual actions
• Land use change
based on activity
distribution
25 November 2010 UT - Decision Support Systems and
Integrated Spatial Modelling 19
Cells have an activity and a land use
LU Activity 1 Activity 2
Residential area
& & with 81 inhabitants
and 22 jobs
Agriculture
& & with 6 inhabitants and 2 jobs
(81)
(6)
(22)
(2)
Activity based approach
Activity based approach
• Activity constrained land use is assigned
according to the activity potential
• Area constrained land uses are assigned to remaining cells
according to their land
use potential
Dynamic economic model
Activity based approach
Land use Population
Wellington population changes
Key facts – Wellington Region
•
Wellington Region 395,610 in 1986 to 487,700 in 2011, expected to reach 541,000 by 2031 (10.7% over 2011)•
Over 3/4 of this growth is projected to be for the 65+ years group•
Gains not shared evenly across age cohorts, declines projected for 0- 14 yrs (-2.3%), 15-24 yrs (-3.3%), and 40-54 yrs (-2.3%), and onlyminor growth for 25-39 yrs (4.3%), but big gains for 65+ yrs (77.2%).
Even more marked changes in 75+ to 85+ yr groups
•
Above based on medium projection series, but very little difference in outcomes if low or high projection series takenTerritorial local authority trends
•
Wellington City accounted for 41% of 2011 population, and for the majority of growth over the period 1986-2011 (55.3%) then Kapiti Coast District at 22.1%•
Natural increase has been the key driver of growth, with netmigration loss (early 90s, 97-01, 07-08) offsetting growth. However, population growth in Kapiti Coast and Carterton Districts was largely due to net migration gains
•
Only Wellington City is projected to have gains at every age group over the projection, with 5 other TAs showing declines in all agegroups under 55+ yrs. Nevertheless, while all show growth in 65+ yr age group, only Wellington City is greater than NZ growth rate
Demographic change: the next 20-30 years
•
Tsunami of grey largest growing cohort is the 65+ yrs age group•
Natural increase will continue to drive population growth•
Continued drift from rural/smaller towns to cities•
Depopulation of inner city suburbs in Upper Hutt City, and possibly Hutt and Porirua Cities, reverse for Wellington City and Kapiti Coast•
No. of people per household will change•
Land use patterns – most of existing housing stock already exists, better connectivity with transport, community facilities, leisure, IT infrastructureSignificant economic consequences
•
Significant labour force impacts•
People choosing to work longer, transitions within industries•
Potentially lesser private, but more public expenditure•
‘Sandwich generation’ economic consequences•
Economy will become more export focused, less domestic influence•
Older generation will require new infrastructure, they may become possibly networkers, financiers of start ups•
Wellington will become more ‘quality’ and ‘quantity’ focused, city design and integration will become an emphasisBUT, do we believe the projections?
