Phase 2 (July 2009 - June 2010)

Toolbox design and impact modelling

Phase 2 (July 2009 - June 2010)

There has been good progress on the project during this period with the Toolbox design completed and several strings of the modelling work well underway. Results from the case studies being performed (see the description of Phase 1 of this study) will be used to demonstrate the various tools described below. The Toolbox will have the following trays (or layers), representing the suggested stages of a comprehensive evaluation:

Toolbox design. [NIWA]

Figure 1: Toolbox design

Top Tray - Understand the Issues

This is the introductory level of the Toolbox, i.e. the tray you see when you first open the Toolbox. The tools in this tray are:
     Tool 1.1 A “how to” guide to using the Urban Impacts of Climate Change Toolbox;
     Tool 1.2 General climate change information and guidance for New Zealand;
     Tool 1.3 An introduction to risk assessment;
     Tool 1.4 Local government functions, the legislative framework and climate change;
     Tool 1.5 Running a council-based workshop – beginning the process of prioritisation;
     Tool 1.6 Sources of information, help and expertise for climate change impact assessments.

Second Tray - Assess the Hazards

The second stage of the evaluation is assessing the hazards that are likely to be exacerbated or introduced associated with climate change. Each urban environment will be exposed to a mixture of different hazards, depending upon their location. For this reason, this tray is divided up into six bins representing different hazards. The tools in each bin are specific to the modelling and assessment of the particular hazard. The hazard bins and tools are:
     Bin 2.1 Flooding
          Tool 2.1.1 General guidance on flood modelling methods used in New Zealand;
          Tool 2.1.2 Examples of flood hazard assessments and mapping;
          Tool 2.1.3 Modelling present-day and future heavy rainfall events;
          Tool 2.1.4 Hydrological modelling of present-day and future floods;
          Tool 2.1.5 Inundation modelling of present-day and future floods.

     Bin 2.2 Sea level rise and storm surge
          Tool 2.2.1 General guidance on assessing future sea level rise and storm surge in New Zealand;
          Tool 2.2.2 Examples of broad-and small-scale assessments of sea level rise and storm surge;
          Tool 2.2.3 Tidal gauge data quality assessment;
          Tool 2.2.4 Modelling present-day and future high tides and storm surge;
          Tool 2.2.5 Inundation modelling of future sea level rise and storm surge.

     Bin 2.3 Heavy rainfall induced landslides
          Tool 2.3.1 General information on the causes of landslides;
          Tool 2.3.2 Examples of rainfall-induced landslides assessments;
          Tool 2.3.3 Collecting and analysis of historical landslide information and data;
          Tool 2.3.4 Rainfall data requirements;
          Tool 2.3.5 Modelling present-day and future landslide potential;
          Tool 2.3.6 Mapping the landslide hazard.

     Bin 2.4 Heavy rainfall and urban drainage
          Tool 2.4.1 General information on urban drainage modelling methods and issues;
          Tool 2.4.2 Examples of urban drainage model assessments;
          Tool 2.4.3 Rainfall data requirements;
          Tool 2.4.4 Modelling of present-day and future pipe network flows;
          Tool 2.4.5 Analysis of service level and disruptions.

     Bin 2.5 Supply and demand of potable water
          Tool 2.5.1 General information on water supply and demand methods and issues;
          Tool 2.5.2 Examples of water supply and demand modelling assessments;
          Tool 2.5.3 Rainfall and temperature data requirements;
          Tool 2.5.4 Modelling present-day and future potable water supply and demand;
          Tool 2.5.5 Analysis of service level and disruptions.

     Bin 2.6 Other hazards
          Tool 2.6.1 General information on the assessment of climate change effects on high winds;
          Tool 2.6.2 General information on the assessment of climate change effects on very high temperatures;
          Tool 2.6.3 General information on the assessment of climate change effects on snowfall;
          Tool 2.6.4 General information on the assessment of climate change effects on fog;
          Tool 2.6.5 General information on the assessment of climate change effects on lightning & hail;
          Tool 2.6.6 General information on the assessment of climate change effects on drought.

Third Tray - Identify the Risks

The third stage of the evaluation is assessing the risks associated with a particular hazard or mix of hazards. This involves assessing what is likely to be impacted by the particular hazard or mixture of hazards. For this project, we are interested in impacts on infrastructure and buildings (i.e. not social impacts). The tools in this tray are:
     Tool 3.1 Climate change risk assessment best practice;
     Tool 3.2 Examples of climate change risk assessments;
     Tool 3.3 Identifying what’s at risk – producing an asset inventory;
     Tool 3.4 Using RiskScape to assess current and future hazard risk;
     Tool 3.5 Subjective risk matrix and screening methods;
     Tool 3.6 Mapping the hazard risk using GIS.

Fourth Tray - Evaluate the Adaptation Options and their Costs and Benefits

The fourth stage of the evaluation is identifying adaptation options to reduce the risk from climate change. Adaptation can be engineering or policy based and should involve no- or low-regrets options that can be changed over time. The tools in this tray are:
     Tool 4.1 Overview of climate change adaptation for urban environments;
     Tool 4.2 Quantitative evaluation of adaptation options;
     Tool 4.3 Ranks-based cost/benefit evaluation of impacts and adaptation options;
     Tool 4.4 Traditional cost/benefit analysis for an at-risk building;
     Tool 4.5 Subjective evaluation options;
     Tool 4.6 Policy-based assessments.

Fifth Tray - Integration of the Information

The fifth and final stage of the process is to ensure that the hazard, risk, and adaptation assessments are integrated into the local government decision-making and planning process. The tools in this tray are:
     Tool 5.1 A check-list for including climate change in the planning process;
     Tool 5.2 Examples of using the local government climate change guidance;
     Tool 5.3 Aligning climate change assessments with sustainable urban growth policies & urban design protocols;
     Tool 5.4 Quantitative assessment of climate change and urban growth scenarios using Riskscape;
     Tool 5.5 Climate change adaptation – planning for coincident benefits.

Progress Report

Multiple strands of work are underway to produce the tools (which will be in the form of short informative reports) that will populate the toolbox.  The work strands have been formalised as 17 sub-projects which are described below (with the progress of each sub-project in italics):

Project 1:  Develop the Urban Impacts Toolkit  Framework and Compile Background Material [On Track; Framework completed and literature review progressing]
Project 2:  Model Sea Level Rise and Storm-Tide Inundation for Avon-Heathcote Estuary, Brighton Spit and Westport [On Track; Tidal data analysed and inundation maps nearly completed]
Project 3:  Model Future Water Supply and Demand for Wellington City using Multiple Climate Change Scenarios [On Track; Sustainable Yield Model output produced for multiple climate change scenarios providing daily and monthly/peak summer demand for Wellington City.  Analysis of output and report preparation progressing
Project 4:  Review Usage of Climate Change Guidance Information in Stormwater Modelling and Management in Auckland [On Track; Literature review of Auckland councils’ policy and operations manuals completed and interviews with councils’ key staff completed]
Project 5:  Provide Climate Change Projection Data for Impact Models [On Track; projection data for all case studies except landslide study provided in desired format]
Project 6:  Model Future Heathcote River Flooding and Inundation [Slightly behind schedule; Rainfall projection data for input into the Heathcote River hydrological and hydraulic models are now based on a simpler method after problems were identified with the original method.  The original rainfall data evaluation process and the issues identified will become an additional ‘tool’ for the toolbox]
Project 7:  Model the Impacts of Heathcote and Brighton Spit Inundation using Riskscape and Evaluate Engineering Adaptation Options [Slightly behind schedule; This sub-project is linked to Project 6 and is affected by the delay identified above]
Project 8:  Model Future Buller River Flooding and Inundation [On Track; Buller River flows for the 1970 Westport flood and climate change projections of the effect of changed rainfall on these flows have been simulated using a hydrological model.  A hydraulic model is currently being run on these flows to produce inundation maps]
Project 9:  Model the Impacts of Westport Inundation using Riskscape and Evaluate Engineering Adaptation Options [On Track; Work using Riskscape was planned to begin in August 2010 contingent upon completion of Project 8. Work has started on developing a process framework for identifying and evaluation engineering adaption options for flooding induced by climate change]
Project 10:  Use Regional Climate Model (RCM) Climate Change Projections for Modelling Wastewater Infrastructure Performance in Auckland [On Track; Significant effort has gone into producing and bias correcting 15-minute rainfall data from the RCM for input into the North Shore City Council wastewater drainage model. The drainage model is currently being run using the RCM data]
Project 11:  Model the Impacts of Current and Future Landslides for Wellington City using Riskscape [On Track; Significant work has gone into the rainfall-induced landslide model development for Wellington City.  Model validation work using city council landslide incident reports is underway
Project 12:  Evaluate Adaptation Options to Reduce Future Landslide Impacts for Wellington City [On Track; A multi-criteria analysis (MCA) approach is being developed to assess adaptation options for selected areas that are vulnerable to landslides
Project 13:  Establish Urban Growth Scenarios for Wellington City to use in Riskscape [On Track; A review of council literature and interviews with Wellington City Council staff have led to urban growth ‘rules of thumb’ being developed that can be incorporated into Riskscape to simulate future landslide risks in proposed growth areas. A report on the Council’s growth scenarios for the City has been prepared]
Project 14:  Review Sustainable Cities Philosophy for City-Wide Building Stock and Stormwater Adaptation Options in Auckland [On Track; A literature review is underway to provide information and policy on the current growth management framework for Auckland Region in the context of managing climate change]
Project 15:  Review “Top-down” Council Decision-Making Process and Assess How Councils Can Optimise the Urban Impacts Toolkit [On Track; A hypothetical landslip case study is being prepared to showcase a ‘planning goals/achievement matrix’ assessment methodology to apply in climate change adaptation responses. An appropriate example has been chosen in discussion with Wellington City Council officers. In addition, an auditing tool is under development for use in identifying inadequacies in the provisions in Council Plans for climate change impacts]
Project 16:  Perform a Detailed Cost/Benefit (or Other) Analysis of Adaptation Options on an At-Risk Building in Westport [On Track; This project is at an early stage as it is tied to Project 9 which is yet to be completed]
Project 17:  Develop a Rapid Cost/Benefit Evaluation Tool and Demonstrate its Applicability in Westport and Christchurch [On Track; Significant work has gone into an international literature review on methods for performing cost/benefit analysis of climate change adaptation options.  A framework for the tool has also been designed]

This year has been the ‘engine room’ of the project with significant effort put into model development, historic and climate change data projections production, literature review and stake-holder interviews.  While some sub-projects are slightly behind schedule due to technical issues, solutions have been found and work on these projects is expected to be back on schedule by the end of 2010.