Fine grained sediment deposition in urban environments during natural hazard events can impact critical infrastructure and properties (urban terrain) leading to reduced social and economic function and potentially adverse public health effects. Therefore, clean-up of the sediments is required to minimise impacts and restore social and economic functionality as soon as possible. The strategies employed to manage and coordinate the clean-up significantly influence the speed, cost and quality of the clean-up operation. Additionally, the physical properties of the fine grained sediment affects the clean-up, transport, storage and future usage of the sediment. The goals of the research are to assess the resources, time and cost required for fine grained sediment clean-up in an urban environment following a disaster and to determine how the geotechnical properties of sediment will affect urban clean-up strategies. The thesis focuses on the impact of fine grained sediment (<1 mm) deposition from three liquefaction events during the Canterbury earthquake sequence (2010-2011) on residential suburbs and transport networks in Christchurch. It also presents how geotechnical properties of the material may affect clean-up strategies and methods by presenting geotechnical analysis of tephra material from the North Island of New Zealand. Finally, lessons for disaster response planning and decision making for clean-up of sediment in urban environments are presented. A series of semi-structured interviews of key stakeholders supported by relevant academic literature and media reports were used to record the clean-up operation coordination and management and to make a preliminary qualification of the Christchurch liquefaction ejecta clean-up (costs breakdown, time, volume, resources, coordination, planning and priorities). Further analysis of the costs and resources involved for better accuracy was required and so the analysis of Christchurch City Council road management database (RAMM) was done. In order to make a transition from general fine sediment clean-up to specific types of fine disaster sediment clean-up, adequate information about the material properties is required as they will define how the material will be handled, transported and stored. Laboratory analysis of young volcanic tephra from the New Zealand’s North Island was performed to identify their geotechnical properties (density, granulometry, plasticity, composition and angle of repose). The major findings of this research were that emergency planning and the use of the coordinated incident management system (CIMS) system during the emergency were important to facilitate rapid clean-up tasking, management of resources and ultimately recovery from widespread and voluminous liquefaction ejecta deposition in eastern Christchurch. A total estimated cost of approximately $NZ 40 million was calculated for the Christchurch City clean-up following the 2010-2011 Canterbury earthquake sequence with a partial cost of $NZ 12 million for the Southern part of the city, where up to 33% (418 km) of the road network was impacted by liquefaction ejecta and required clearing of the material following the 22 February 2011 earthquake. Over 500,000 tonnes of ejecta has been stockpiled at Burwood landfill for all three liquefaction inducing earthquake events. The average cost per kilometre for the event clean-up was $NZ 5,500/km (4 September 2010), $NZ 11,650/km (22 February 2011) and $NZ 11,185/km (13 June 2011). The duration of clean-up time of residential properties and the road network was approximately two to three months for each of the three liquefaction ejecta events; despite events volumes and spatial distribution of ejecta. Interviews and quantitative analysis of RAMM data revealed that the experience and knowledge gained from the Darfield earthquake (4 September 2010) clean-up increased the efficiency of the following Christchurch earthquake induced liquefaction ejecta clean-up events. Density, particle size, particle shape, clay content and moisture content, are the important geotechnical properties that need to be considered when planning for a clean-up method that incorporates collection, transport and disposal or storage. The geotechnical properties for the tephra samples were analysed to increase preparedness and reaction response of potentially affected North Island cities from possible product from the active volcanoes in their region. The geotechnical results from this study show that volcanic tephra could be used in road or construction material but the properties would have to be further investigated for a New Zealand context. Using fresh volcanic material in road, building or flood control construction requires good understanding of the material properties and precaution during design and construction to extra care, but if well planned, it can be economically beneficial.
The Canterbury earthquake sequence in New Zealand’s South Island induced widespread liquefaction phenomena across the Christchurch urban area on four occasions (4 Sept 2010; 22 Feb; 13 June; 23 Dec 2011), that resulted in widespread ejection of silt and fine sand. This impacted transport networks as well as infiltrated and contaminated the damaged storm water system, making rapid clean-up an immediate post-earthquake priority. In some places the ejecta was contaminated by raw sewage and was readily remobilised in dry windy conditions, creating a long-term health risk to the population. Thousands of residential properties were inundated with liquefaction ejecta, however residents typically lacked the capacity (time or resources) to clean-up without external assistance. The liquefaction silt clean-up response was co-ordinated by the Christchurch City Council and executed by a network of contractors and volunteer groups, including the ‘Farmy-Army’ and the ‘Student-Army’. The duration of clean-up time of residential properties and the road network was approximately 2 months for each of the 3 main liquefaction inducing earthquakes; despite each event producing different volumes of ejecta. Preliminary cost estimates indicate total clean-up costs will be over NZ$25 million. Over 500,000 tonnes of ejecta has been stockpiled at Burwood landfill since the beginning of the Canterbury earthquakes sequence. The liquefaction clean-up experience in Christchurch following the 2010-2011 earthquake sequence has emerged as a valuable case study to support further analysis and research on the coordination, management and costs of large volume deposition of fine grained sediment in urban areas.
A magnitude 6.3 earthquake struck the city of Christchurch at 12:51pm on Tuesday 22 February 2011. The earthquake caused 182 fatalities, a large number of injuries, and resulted in widespread damage to the built environment, including significant disruption to the lifelines. The event created the largest lifeline disruption in a New Zealand city in 80 years, with much of the damage resulting from extensive and severe liquefaction in the Christchurch urban area. The Christchurch earthquake occurred when the Canterbury region and its lifelines systems were at the early stage of recovering from the 4 September 2010 Darfield (Canterbury) magnitude 7.1 earthquake. This paper describes the impact of the Christchurch earthquake on lifelines by briefly summarising the physical damage to the networks, the system performance and the operational response during the emergency management and the recovery phase. Special focus is given to the performance and management of the gas, electric and road networks and to the liquefaction ejecta clean-up operations that contributed to the rapid reinstatement of the functionality of many of the lifelines. The water and wastewater system performances are also summarized. Elements of resilience that contributed to good network performance or to efficient emergency and recovery management are highlighted in the paper.
Questions to Ministers
1. Dr RUSSEL NORMAN to the Minister of Finance: Does he agree with 57 percent of New Zealanders who, according to a recent UMR poll, support the introduction of a temporary earthquake levy to pay for the rebuilding of Christchurch?
2. Hon PHIL GOFF to the Prime Minister: What, according to the 2010 Investment Statement of the Government of New Zealand, was the average total shareholder return over the last five years from State-owned Enterprises and the average bond rate, and is that consistent with his statement that "it is the Government's intention to use the proceeds of those initial public offerings to actually invest in other assets that the Government would have to fund through the Government bond rate"?
3. DAVID BENNETT to the Minister for Infrastructure: What progress has the Government made on its infrastructure programme?
4. Hon ANNETTE KING to the Prime Minister: Does he stand by his statement "this Government is not prepared to turn its back on our most vulnerable citizens when they most need our help"?
5. Hon JOHN BOSCAWEN to the Acting Minister of Energy and Resources: Is it government policy for New Zealand to become a "highly attractive global destination" for oil exploration, with expansion of the oil and coal sectors leading to a "step change" in the country's economic growth as set out in the document Developing Our Energy Potential; if not, why not?
6. Hon CLAYTON COSGROVE to the Minister for Social Development and Employment: Is the Government considering extending the business assistance package for employers and employees beyond the 14-week period currently signalled; if not, why not?
7. JACQUI DEAN to the Minister of Police: What reports has she received on the latest trends in the level of crime in New Zealand?
8. Hon TREVOR MALLARD to the Prime Minister: Did he tell a meeting in Timaru last week "The entire time I've been Prime Minister I've had Treasury in my office week after week, month after month, telling me South Canterbury Finance was going bankrupt"?
9. CHRIS AUCHINVOLE to the Minister for the Environment: What advice has he received on major resource consents being considered under the Government's new national consenting policy?
10. Dr RUSSEL NORMAN to the Acting Minister of Energy and Resources: Does she agree that the joint scheme initiated by the Green Party and the Government, Warm Up New Zealand: Heat Smart, is the best initiative in the Draft New Zealand Energy Strategy because it is providing hundreds of thousands of New Zealand households with warm, dry, energy efficient homes, and creating thousands of clean green jobs?
11. Hon SHANE JONES to the Minister of Fisheries: Does he still have no major concerns about the way foreign boats were used by New Zealand companies as the Nelson Mail reports he said last year?
12. TIM MACINDOE to the Minister of Housing: What recent announcements has he made regarding the Government's Housing Innovation Fund?
ANDREW LITTLE to the Prime Minister: Does he have confidence in the Minister for Building and Housing given the falling rate of homeownership, especially among young people?
RON MARK to the Prime Minister: Does he stand by all his statements?
MATT DOOCEY to the Minister of Finance: Does he stand by his statement that “There are more jobs, and people are being better paid”; if so, why?
Dr MEGAN WOODS to the Minister supporting Greater Christchurch Regeneration: Does he agree with the Prime Minister, who said with regard to the Canterbury earthquakes, “on behalf of the Government, let me be clear that no one will be left to walk this journey alone”; if so, does he think all relevant information prepared by his Government has been made available to Cantabrians to assist them in navigating post-earthquake decisions?
METIRIA TUREI to the Prime Minister: Ka tū a ia i runga i te mana o āna kaupapa here Kāwanatanga katoa, nē?
Translation: Does he stand by all his Government’s policies?
Dr JIAN YANG to the Minister of Education: What recent announcements has she made about expanding 21st century learning options for parents and whanau?
CHRIS HIPKINS to the Minister of Education: How will her Communities of Online Learning (CoOL) proposal differ from online charter schools in the United States, given a study partially funded by a private pro-charter foundation found students attending those schools lost an average of about 72 days of learning in reading, and 180 days of learning in maths during the course of a 180-day school year?
CATHERINE DELAHUNTY to the Minister for the Environment: Will he commit to a regulatory regime that includes swimmable rivers in light of the comment from a Havelock North café owner who said that, “we’d trade all the compensation in the world if it would spur the Government into tidying up or cleaning up the waterways”?
IAIN LEES-GALLOWAY to the Minister of Immigration: How many of the 209,000 work visas issued last year were for occupations on one of the Essential Skills in Demand lists?
JONO NAYLOR to the Minister of Police: What is the Police doing to assist potential victims of family violence?
STUART NASH to the Minister of Police: Does she believe that the Police have enough resources to implement their part of the Prime Minister’s 2009 promise to use the full force of the Government’s arsenal to “confront the P problem” given that P is cheaper, and as easy as it was to get in 2008?
PAUL FOSTER-BELL to the Minister for Primary Industries: What recent reports has he received on growth in wine exports?
