1 of 18 Geo_Y05_U2_SS_Floods Floods The covering of normally dry land by water.

2 of 18 Geo_Y05_U2_SS_Floods How floods occur… Cyclones push on the ocean and create a ‘storm surge’. This raises sea levels as the cyclone approaches the shore and can cause flooding. Storms can release large volumes of water in a short period of time. A large amount of water can overwhelm creeks and rivers causing flooding. Tsunamis are often a result of earthquakes under the ocean. The earthquakes move water to make huge waves that flood the land.

3 of 18 Geo_Y05_U2_SS_Floods Major flooding in Australia The eastern states QLD, VIC and NSW all experience regular major flooding events. Many rural towns east of the Great Dividing Range experience flooding when seasonal rains occur. Brisbane has experienced three major floods, 1893, 1974 and 2011.

4 of 18 Geo_Y05_U2_SS_Floods What town in Queensland, west of the Great Dividing Range is at risk of flooding? What type of flooding would you expect? How does the Great Dividing Range change the type of flooding? Which type of flooding do you think is the most dangerous to people?

5 of 18 Geo_Y05_U2_SS_Floods How people make floods worse Deforestation: Trees help absorb water and reduce water running into and flooding waterways. Littering: Rubbish can get into stormwater drains, plugging them and increasing the risk of flooding. Building in low lying areas: Building in areas prone to flooding damages property. Ignoring warnings: People who ignore flood warnings (particularly crossing water in cars) put emergency services people at risk.

6 of 18 Geo_Y05_U2_SS_Floods The severity of a flood influences its effects Minor floods: Only low-lying areas are affected. Some roads are flooded. Moderate floods: Evacuation of people may be required. Major roads are flooded. Major floods: Properties and towns are cut off. Evacuation of people is required. Essential supplies may need to be transported to affected areas by boat or helicopter.

7 of 18 Geo_Y05_U2_SS_Floods Flood warning systems Radars allow forecasters to predict the amount of rain contained in clouds. Sensors/gauges and surveillance cameras up stream monitor river levels. Road signs for roads that flood often.

8 of 18 Geo_Y05_U2_SS_Floods Types of monitoring systems Shed housing a water monitoring system. Advanced solar powered monitoring system.

9 of 18 Geo_Y05_U2_SS_Floods Effects of flooding Adds to soil fertility Loss of human life Relief for drought conditions Loss of homes and jobs Psychological effects Disruption to water supply, electricity, transport, education, communications Loss of habitats Spread of disease Downturn in tourism Damage to property and loss of land value Removal of vegetation and topsoil Dispersal of weed species Damage to crops, fencing and loss of livestock

10 of 18 Geo_Y05_U2_SS_Floods Impacts of floods can be categorised as……. Economic factors Factors relating to money (for example: damage to property, business, roads). Environmental factors Factors relating to natural features (for example: washing away of vegetation and topsoil). Social factors Factors relating to people and communities (for example: assisting those in need).

11 of 18 Geo_Y05_U2_SS_Floods Children's stories from severe storms/flooding ‘We usually switch off all the power points.’ ‘The sky goes real dark. It goes all grey and you know there’s a storm coming.’ ‘Stuff everywhere, random things, trees fallen down, just water everywhere… mud. Bits of debris from other people’s houses…’ ‘The roads … were flooded still, and no one could really go out much. The shopping centres were closed.’ ‘Branches off trees, big power poles fallen over, wires hanging from them, cars crashed…’

12 of 18 Geo_Y05_U2_SS_Floods Case study: Queensland floods December 2010 – January towns affected ¾ of Queensland declared a disaster zone.

13 of 18 Geo_Y05_U2_SS_Floods Case study: Queensland floods

14 of 18 Geo_Y05_U2_SS_Floods Case study: Queensland floods

15 of 18 Geo_Y05_U2_SS_Floods Impact on communities 38 people lost their lives Damage to property, crops, livestock Damage to infrastructure (for example: clean water, waste water, electricity, transport, communication, petrol) Economic impacts (for example: cost of damage, cost of clean up) Disruption to industry (for example: coal) Downturn in tourism

16 of 18 Geo_Y05_U2_SS_Floods Response to the event Releasing water from dams Building towns / houses on higher ground New Council regulations to prevent building on flood- prone land Building dams and levees Early warnings for evacuation Reforestation Floodways to divert water Helping others in the community to recover Wivenhoe dam spillway opened to release water January 2011.

17 of 18 Geo_Y05_U2_SS_Floods Reflecting on the Brisbane floods How did the flood affect people? How did communities respond to the flood? If Brisbane was a small town, would the flood have had the same effect on the community?

18 of 18 Geo_Y05_U2_SS_Floods Attributions Slide 4© Commonwealth of Australia (Geoscience Australia) CC BY 3.0 creativecommons.org/licenses/by/3.0/au/deed.en Slide 7 Slide 8© Commonwealth of Australia CC BY 3.0 creativecommons.org/licenses/by/3.0/au/deed.en © Commonwealth of Australia CC BY 3.0 creativecommons.org/licenses/by/3.0/au/deed.en Slide 11Rain, hail and shine (Dept. of Community Safety) CC BY NC I can see clearly now (Dept. of Community Safety) %20i%20can%20see%20clearly%20now.wmv CC BY NC Slide 12NASA, Slide 13Sweetbixkid, CC BY 3.0 creativecommons.org/licenses/by/3.0/deed.en Slide 14 Used with permission. Slide 15 PMBO, CC BY 3.0 creativecommons.org/licenses/by/3.0/deed.en Slide 16Courtesy of: Greta Creed. Used with permission. Reference: