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Transcript of Australian Floods
Where is this Natural Hazard Generally Located?
Flooding generally occurs in low-lying areas near to streams and rivers. In the extensive flat inland regions of Australia, floods may spread over thousands of square kilometers and last several weeks. In the mountain and coastal regions of Australia flooding can happen rapidly with limited warning.
Flash floods can occur almost anywhere where short intense burst of rainfall occur such as during a thunderstorm. As a result of these events the drainage system has insufficient capacity to hold a significant amount of water.
The Physical Process of a Flood
There are many reasons why floods occur, these can be divided into categories of causes. These are flash floods, storm surge, and dam and levee failures.
These types of flood occur with little or no warning. The that factors that contribute to the occurrence of flash floods include rainfall intensity, duration, surface condition and topography. Urban areas are more susceptible to flash floods due to the lack of natural drainage systems as there is no where for water to go so it just stays in one place.
Storm surges inundate coastal margins due to severe onshore winds, often accompanied by low atmospheric pressure and sometimes high tides. Friction between moving air and the water creates drag. Depending on the distance over which this process occurs and the velocity of the wind, water can pile up to depths of over 7 meters. Intense, low-pressure systems and tropical cyclones often cause storm surges.
Dam and Levee Failures
Dam and levees are designed to contain a flood at a location on a water way. If the flood is larger than the one predicted the structure built to contain it will be over topped and will fail. This causes a sudden burst of water which causes a flash flood downstream.
The Queensland Flood of 2010 - 2011
Queensland flood location map
How and Where Did the Queensland Floods Started:
During July to December 2010, extremely heavy rainfall was
experienced across large parts of eastern Australia, with Queensland
experiencing its wettest spring on record. This rain pattern was
influenced by the strongest La Niña affect in the Pacific Ocean as a result Queensland’s river catchments were significantly overflown before major rain events occurred during November 2010 to April 2011. Tropical Cyclone Tasha, Anthony and Yasi struck during these floods causing torrential rain, flooding of many other towns causing towns to be evacuated and with overflowing river catchments and rivers reaching up to 18 meters over its peak causing this major flood.
The Social, Economic and Environmental Impacts
The social impact of the floods include people being left homeless due to destruction and flooding of their homes. Flooding spread disease as it mixed with the towns bathroom water from toilets and can accidentally consumed. By the end of the floods 35 people were declared dead due to these floods.
The economical impacts include damage to houses which need to be payed, business' slowdown and people cannot work to provide money for their families. The federal government had to pay for rescue aid and also food products will be limited and the prices go up around Australia due to farms being flooded and no crops can grow. The flooding was estimated to cost Australia $10billion.
Environmental impacts include habitats being destroyed which causes animals to die due to no food sources available or being drowned in the flood. Trash and debris were flown around from winds or carried off from the water flow escaping into rivers, lakes and oceans polluting the water and killing animals.
The Response of the Floods from Individuals, Groups and Governments
Ms Anna Bligh, Queensland Premier at the time, response to these floods were
"Now is not a time to panic, it is a time for use to stick together".
Ms Bligh is encouraging the people affected to stay calm and to help each other as best as they can.
Many people had no idea of where to go after being evacuated from their homes. The city council was prompt to get an evacuation centre up for people to find shelter.
The executive director of the Australian Red Cross, Greg Goebel, stated that
"Ipswich residents are distressed but coping well".
Ms Gillard (PM at the time) said
"We were giving payments and support for people in recovery and then all of the rebuilding to do".
The organisation lifeline were collecting donation for people affected by the floods and provided counselling for call centres across the country for the flood victims.
A strategy that could have avoided the adverse effects of the event:
To avoid the adverse effects of this flooding to the social impact the government could have looked closer at forming weather so that that that could have informed areas that were hit with tropical cyclones so they could pack and evacuate their town to avoid as many deaths that occurred in the 2010 - 2011 Queensland floods.
A strategy that could have made the response more effective:
The emergency services could have responded faster to avoid as many loss of lives. More support centres could have been opened for more people to come and get shelter and food.