EV5454: Environmental Science - Natural Hazards - Assessment Aswer

Environmental Science Assignment

Assignment Task

Project

For your project you will be required to:

1. map the probable spatial extent of impact of a major natural hazard event on the immediate Cairns

region;

2. outline the causes of this event or events;

3. discuss the magnitude and frequency of occurrence of this hazard, and explain how you arrived at

these figures;

4. discuss the impact this event would have on the infrastructure, dwellings and people of Cairns;

5. discuss the vulnerability of those potentially affected, and why these people are vulnerable;

6. discuss ways of mitigating the impact of this natural hazard.

Your report will be due by 5pm Friday 7th October, 2016. Late penalties will apply for work submitted

after this time and date.

You will be required to submit the report on safe assignment Learn JCU.

INTRODUCTION

“The Natural hazards/ disasters have a considerable impact on economy, environment and political scenario of a community. Though a human being can to a certain extent mitigate the impact of a natural disaster but cannot eliminate it completely. Therefore, the disaster management groups need to make decisions regarding what risks and to what extent these risks are acceptable to the community. ("Cairns District Disaster Management Plan", 2016)

Cyclone is a type of natural hazard which causes rigorous and extensive damage to coral reefs. Cyclones are usually associated with heavy rains which can lead to flood trails which can kill the micro organisms like corals and seagrasses. However, the waves and currents which are caused due to powerful winds can lead to rigorous physical damage. The cyclones, not only have direct impacts but also indirect impacts, like, damage to the little micro organisms in the reef area due to the rubble and boulders which are mobilized by the storm’s energy.

A cyclone is so powerful that it can also result in complete destruction of communities located in the reef area and also scouring of substrate in that area. However, the differences in the severity of the cyclones and the sensitivity of the species can result in variable damages. The destructive nature of cyclones has a major influence on the structure and development of the areas near coral reefs. The Great Barrier Reef in Cairns covers an area which is very frequently exposed to cyclones and its damaging effects. This region experienced 116 cyclones in the span of 36 years (1970 to 2006).

The credit of evolution of reef ecosystems can be given to the more severe end rigorous cyclones, which are continuously increasing in frequency. For example, for the last three decades, the frequency of severe cyclones has almost doubled. Due to increase in rigorous cyclones in the coral reef area by double, it has been predicted that the coral mortality will also increase by 60 percent which will result in bad impacts on communities and industries which are reef dependent. The importance of cyclones to the Great Barrier Reef in Cairns has been established by the huge impacts of the two large cyclones that have adversely affected the areas around Reef in the last few years.

TC Hamish when traversed along the southern reef caused severe damages in that reef area in the year 2009. Due to the flow- on effects of this cyclone, many other reef areas also suffered severe damages which were in terms of damage to the species, the human habitats and also the fish industries, dependent on the reef areas. Although, TC Hamish did not go beyond the coastal area and did not cause much damage to the towns and infrastructure, but, it was still declared to be one of the most destructive cyclone to affect the coastal reef since 1900s.

Two years later, TC Yasi hit the Great Barrier Reef, and entered the reef region and crossed the coastal regions of queensland. TC Yasi which hit the great barrier reef in February 2011 was measured to be one of the largest and most severe cyclones to affect Cairns in the history of cyclones. The Meteorological Bureau investigated this cyclone and rated it to be a category 5 cyclone with the maximum wind gusts estimated to be about 285 km/h. Within the marine park boundary, 775 of the 2900 reefs were exposed to gale force and destructive winds. In accordance with the large history on cyclone exposure, the severity of TC yasi had the power to cause unparalleled amount of destruction to the reef ecosystem. This report will assess the spatial extent and level of physical destruction caused by TC Yasi to the great barrier reef. A perception of the impacts of the rigorous storms is also useful for better management of reef areas, which are under increasing pressures from human use and climate change. Learning about the impacts of these kinds of events is necessary for future development of strategic management policies which support the spirit of the ecosystem of the Great Barrier Reef and Reef-based industries in the face of climate change. ("Cairns District Disaster Management Plan", 2016)

SCALE AND SPATIAL PATTERNS OF THE DAMAGE

Various surveys were carried out to measure the scale and pattern of the damage caused by TC Yasi which documented a large amount of coral destruction in the area of 89,090 km2 of the marine park caused due to the powerful and destructive winds of TC yasi. In accordance with the calculation, only about 15 % of the 24,839km2 great barrier reef area is projected to have survived some extent of the coral damage and only 6 per cent (1,513 km2) sustained severe coral damage and to some extent structural damage also as a result of harmful effects of TC Yasi. ("COMMUNITY RISK IN CAIRNS", 2016)

The amount of ecological destruction is dependent on the Location of reefs with respect to the eye of a cyclone caused by its passage. In accordance with the previous studies, the severity of a damage and the ratio of the sites suffering damage increases with the proximity to the eye of the cyclone. There is a tendency of more damage to the left side of the traverse direction of the cyclone which increases the tendency of more damage on the left side. The most considerable destruction happened at the 61 coral reefs which were in the zone of very destructive winds. Out of the total Great Barrier Reef, 58 (95 %) suffered the most severe destruction in terms of living communities, with structural destruction of 47 (78%) out of total 61 reefs which were facing the very destructive winds. Towards the north of Cairns, destruction was less severe with only 35 – 45% within 100 km of the cyclone eye which recorded some degree of structural destruction.

The reefs which were more than 250 km away from the cyclone eye reported lower severity of damage, they also recorded zero structural damage. Therefore, in accordance with the surveys, as the distance of the area with respect to the cyclone eye increased, the damage to the area decreased. However, the surveys recorded that there was minor or no coral damage at sites which were 150 km away from the coral eye. The tendency of damage at the outer shelfs was more in comparison to the mid shelf reefs. The spatial damage from the cyclone is highly variable. In some occurrences, the survey came to some sites which had to suffer only a minor amount of damage within 100 m of sites where live coral cover was brought down to less than 5%. ("COMMUNITY RISK IN CAIRNS", 2016)

CAUSES OF THIS EVENT

The two main factors in the formation of any cyclone are- (1) warm water body and (2) cumulonimbus clouds which gathers together at a place. The warm water body basically evaporates in the sky and makes clouds and also releases heat energy out of itself. This release of heat, together with the Earth's rotation forms the whirling effect which is usually found in cyclones. ("Cyclone Yasi: What happened five years ago", 2016)

Cyclone Yasi happened because all the weather conditions which are required to form a cyclone were present- like warm sea and the cumulonimbus clouds. Cyclone Yasi brought about such huge destruction because of its elongated journey across the seas in the tropical areas. As the Yasi Cyclone traversed from North Vanuatu to the coast of Queensland, the only major landmass which came in its path was New Caledonia, which did not affect its intensity in any manner. Consequently Yasi travelled a long distance across the tropical regions, growing its intensity the whole time. ("Cyclone Yasi: What happened five years ago", 2016)

DISCUSS THE MAGNITUDE AND FREQUENCY OF OCCURRENCE OF THIS HAZARD, AND EXPLAIN HOW YOU ARRIVED AT THESE FIGURES

The destructive nature of cyclones has a major influence on the structure and development of the areas near coral reefs. The Great Barrier Reef in Cairns covers an area which is very frequently exposed to cyclones and its damaging effects. This region experienced 116 cyclones in the span of 36 years (1970 to 2006). The credit of evolution of reef ecosystems can be given to the more severe end rigorous cyclones, which are continuously increasing in frequency. For example, for the last three decades, the frequency of severe cyclones has almost doubled. Due to increase in rigorous cyclones in the coral reef area by double, it has been predicted that the coral mortality will also increase by 60 percent which will result in bad impacts on communities and industries which are reef dependent. The importance of cyclones to the Great Barrier Reef in Cairns has been established by the huge impacts of the Yasi cyclone that has adversely affected the areas around Reef in the last few years. ("impacts of tropical cyclone yasi on the great barrier reef", 2016)

TC yasi hit the Great Barrier Reef, and entered the reef region and crossed the coastal regions of queensland. TC Yasi which hit the great barrier reef in February 2011 was measured to be one of the largest and most severe cyclones to affect Cairns in the history of cyclones. The Meteorological Bureau investigated this cyclone and rated it to be a category 5 cyclone with the maximum wind gusts estimated to be about 285 km/h. Within the marine park boundary, 775 of the 2900 reefs were exposed to gale force and destructive winds. In accordance with the large history on cyclone exposure, the severity of TC yasi had the power to cause unparalleled amount of destruction to the reef ecosystem. This report will assess the spatial extent and level of physical destruction caused by TC Yasi to the Great Barrier Reef. ("impacts of tropical cyclone yasi on the great barrier reef", 2016)

A perception of the impacts of the rigorous storms is also useful for better management of reef areas, which are under increasing pressures from human use and climate change. Learning about the impacts of these kinds of events is necessary for future development of strategic management policies which support the spirit of the ecosystem of the Great Barrier Reef and Reef-based industries in the face of climate change.

The surveys conducted on reef damage used a rapid assessment approach to: (1) calculate the severity and extent of damage to the coral reefs which faced the damaging winds of Yasi and (2) The surveyors collected photos and videos to demonstrate the nature and magnitude of damage to the communities near coral regions. Wherever it was possible, the surveyors made the reef sites their target in relation to which there was pre cyclone data available. In between 10 February and 17 March 2011, the GBRMPA and QPWS, the special survey teams in connection with the tourism industry and fishing industries and AIMS, studied 76 reefs to evaluate the impact of Yasi on the Reef. ("COMMUNITY RISK IN CAIRNS", 2016)

DISCUSS THE IMPACT THIS EVENT WOULD HAVE ON THE INFRASTRUCTURE, DWELLINGS AND PEOPLE OF CAIRNS

TC Yasi cyclone produced great structural storm destruction and also structural wind destructions at various places between Innisfail and Townsville. The warnings about the upcoming cyclone were widely reported amongst the public, therefore, the people had started evacuating the low-lying areas of Cairns and Townsville. Many people shifted to their friend’s place which they felt was the strongest. Therefore, there were no casualties reported which may have occurred if the buildings which were badly destroyed were occupied during the cyclone.

The roofs of many of the houses were torn off, many were flattened and as many as 1000 people said that their homes were damaged. (james cook university, 2016)

There was power cuts in as many as 200000 properties and even after a month of cyclone there was 700 houses without power because they were considered unsafe for power connection.

The surge of tide in the cardwell coast came as close to the seven-meter level and there were boats floating in that area. The Bruce Highway along the Cardwell waterfront was badly damaged.

There were about a dozen boats in the Port Hinchinbrook Marina, which were piled on top of each other.

The department of Agriculture and Resource Economics and Sciences gave an estimation of about $300 million damage to agricultural production due to cyclone, where banana and sugar cane crops were in particular badly hit. (james cook university, 2016)

VULNERABILITY OF THOSE POTENTIALLY AFFECTED, AND WHY THESE PEOPLE ARE VULNERABLE

A systematic approach should be used to describe the risk elements and their vulnerability to hazard impact. The vulnerability of the potentially affected people can grouped in the following four elements: setting, shelter, sustenance and security.

• Setting: basic vulnerability includes access to the physical environment like the climate, geology, land use, topography, etc.
• Shelter: The people were vulnerable towards their shelter needs. For the affected people, access to shelter was significant, so they wanted information on mobility within the community.
• Sustenance: The affected people were vulnerable towards the supply of utility and service infrastructures such as water supply, sewerage, power supply and telecommunications because these are the basic infrastructures for sustaining a life.
• Security: the security of the community is measured in terms of its health and wealth and by the forms of protection that are provided. Physically, these may be assessed by the availability of facilities such as hospitals, industries, agricultural land use, fire stations, police stations and works such as flood retention basins. Therefore the people of the great coastal reef were vulnerable towards the availability of these services because there was huge damage caused by the Yasi cyclone. ("COMMUNITY RISK IN CAIRNS", 2016)

WAYS OF MITIGATING THE IMPACT OF THIS NATURAL HAZARD.

A natural hazard to some extent can be mitigated by following the Disaster Management Strategic Policy Framework. This can be done by:

• Following a complete, all hazards, all agencies way by striking a right balance of prevention, being prepared for a disaster, response and recovery;
• Being prepared for a disaster and following the relevant areas of activity of government, non-government, small business and corporations;
• bringing in line the disaster risk reduction programs, disaster mitigation programs and disaster resilience programs with the international and national reforms;
• Aligning a transparent and systematic approach to disaster risk assessment and management, on the basis of National Emergency Risk Assessment Guidelines and the Australian/New Zealand Standard AS/NZS ISO 31000:2009 Risk management – Principles and guidelines;

The philosophy underlying the ‘Disaster Management’ planning in Cairns is based on the principle of nationally known ‘Comprehensive approach’ ‘Prevention, Preparedness, Response and Recovery’. These principles are referred to in the Disaster Management Act (QLD) 2003- Reprinted as in force on 1 November 2010. These principles are referred to at Part 3 of the Disaster Management Act (QLD) 2003. ("Cairns District Disaster Management Plan", 2016)