Floods CGF 3M1 Unit 2 Course Overview 1. Geographic Approaches 2. Dynamic Earth 3. Humans on Earth 4. Interdependence 5. Natural Disasters Unit Overview 1. 2. 3. 4. 5. 6. Earthquakes and Volcanoes Tsunamis Floods Avalanches Tornadoes Hurricanes Floods • explain the connections between physical processes, the landscapes they create and the resulting hazards • explain the concept of spatial significance as it relates to natural hazards and disasters • apply Geographic Perspectives to natural hazards and disasters. Floods • Understanding how and where flooding occurs as well as what changes they make to the landscape can help us manage risks accordingly Floods ✔I can accurately describe different types of landscapes; ✔I can accurately describe different types of physical processes; ✔I can logically explain the connections between physical processes and natural hazards; ✔I can accurately describe how processes and hazards influence landscapes; ✔I can analyse the connections between different types of processes/hazards and how they influence each other. Floods ✔I can accurately identify a location’s natural and human characteristics and relate them to natural hazards and disasters; ✔I can interpret the significance of natural and human characteristics to explain how they affect the risk of hazards and disasters; ✔I can make relevant connections between the importance of spatial distribution and human/natural features. Floods ✔I can accurately identify a point of view from an environmental, social, political and economic perspective; ✔I can explain the characteristics of geographic perspectives using appropriate support; ✔I can logically compare various geographic perspectives relevant to the natural hazard and disasters; ✔I can appropriately analyse multiple perspectives related to natural hazards/disasters. Floods • Flooding 101 • https://www.youtube.com/watch?v=4PXj7bOD7I Y Floods • Flooding events are the most frequent and costly natural hazards that humans encounter. • At any given time, there are numerous locations on Earth experiencing flooding as a result of heavy precipitation, hurricane storm surges, or even tsunamis triggered by geologic events. • Flooding in Canada is becoming such a problem, that huge areas are no longer insurable against flooding. Floods Floods • Where are flood events occurring? Are there patterns or trends in their occurrence? • What natural events are causing the flooding in these places? What features create the unique spatial significance? • How is the flooding affecting people? How are people affecting the flooding? What interrelationships exist? • How would you feel if this were happening in your community? What geographic perspectives exist? Floods • Flooding is most often a natural process that occurs anywhere an excess of water accumulates. • However, floods can also have human origins. For instance, human activities, such as dams, create controlled flooding situations. Floods • However, the most dangerous floods are created by natural and unpredictable circumstances. • There are no complexities involved other than identifying the source of the excess water. • Floodwaters can be created as a result of a few situations, each with their own unique spatial significance. Floods • Part 1: Causes of Flooding • Take notes on the various causes of flooding as you look at the infographic, read the handout, and look at the photos on the next few slides. • Summarize the key points of information so you do not have to keep reading the full documents. Floods - Causes 1. Sustained heavy rainfall Floods - Causes 2. Rapid snowmelt Floods - Causes 3. Storm surges from hurricanes. Surface height of ocean water increases as wind “pushes” the water, making giant waves Floods - Causes 4. Tsunamis Floods - Causes 5. Controlled human activity Floods - Causes 6. Uncontrolled human activity Floods • Part 2: Influence of Water and Flooding on the Landscape Floods • In the first lesson of this unit, you learned that earthquakes and plate tectonics are able to create towering mountain ranges or deep ocean trenches over the course of millions of years. • The long term erosive actions of water also create magnificent landscapes, sometimes over the course of only a few years. • The power of water is no better seen than by looking at a few of the landscapes it has created. Canyons Weathering and erosion of rock material by river Badlands Floodplains Every river will flood at some point. A flood plain is an area of flat land alongside a river. This area gets covered in water when the river floods. When the water recedes, the sediment (mud, debris) from the water is left on the land Flood plains are naturally very fertile due to the river sediment which is deposited there. This sediment is good for growing plants on the flood plain. The St. Lawrence Lowland area is a flood plain beside the St. Lawrence River in Quebec. Some of the best farm land in Canada Flooding Creates Floodplains (River) Deltas • • The Mississippi Delta Deltas are fan shaped landforms created where rivers meet bodies of water. The fast moving river water slows down and deposits sediment, creating an intricate network of channels and sand bars that extend out into the water. Deltas are particularly susceptible to flooding as they are low lying, must direct the entire flow of the river, and usually meet oceans where hurricane storm surges pose additional threats. Downtown Uxbridge Floodplain (based on Hurricane Hazel 1954) Downtown Uxbridge Floodplain (based on Hurricane Hazel 1954) Uxbridge Brook underneath Downtown Original culvert construction 34 Uxbridge Culvert c. 2018 • • • • This was the state of the culvert in 2018. It could only hold a “1 in 100 year” flood event. Hurricane Hazel was TEN TIMES that amount! If a regional flood were to occur, 2 metres of water would flow through downtown. Downtown Uxbridge Streetscape Downtown Uxbridge Streetscape IF we have another major storm and didn’t replace the culvert. Uxbridge Culvert • This construction project removed the previous culvert that ran under Downtown Uxbridge and replaced it with a pair of concrete culverts. Uxbridge Culvert Replacement culvert construction September 22, 2020 Check your Understanding • No go back to the content page and complete Activity Floods• Part 3: Flooding Case Study - 2013 Calgary Flood Floods • Now that we understand the causes of floods and some terms and landforms associated with them, we will use the concept of geographic perspectives to study a famous Canadian flood. • Start by looking at the satellite imagery of the flood from before and during this event. • Esri ArcGis maps1. After you have followed the link to the map site, you will need to save your maop GO to the Esri ArcGis site Calgary Pre-Flood Calgary During the Flood Activity Floods • Explore the story map (link on the next slide) and complete the Calgary Flood Case Study. • The activity requires you to think from the perspective of someone else, which is sometimes hard to do. • For some tips on how to think from someone else's perspective read the article “Empathetic Intelligence”. Floods • Geographic Perspectives on a Canadian natural disaster: Complete the handout as you explore the story map. • http://onedu.maps.arcgis.com/apps/Cascade/ind ex.html?appid=112535f7a0184ca89cbc7586928 c01c9 Floods ArcGIS Story Map not working? 1. Use the “How to Login to ArcGIS Online” to get it working. Or if THAT doesn’t work... 2. Use the “Calgary Flood Case Study Story Map” slideshow that is a collection of screenshots of the real Story Map. Floods • The Calgary Zoo was hit hard by the flood, as it is located on the river bank and a small island within the river. • Knowing this information is important. However, to better understand the flood’s impact on all people (and animals) connected to the zoo, you read the article Flood at the Zoo: The Inside Story. Activity Floods • Once you have read this article, imagine the information that other individuals and stakeholders would find most important and significant based on their perspective. • Complete the Flood at the Zoo Chart as a way of organizing information from the article. Submit your completed chart. To Keep Up-to-Date… Clear your Google Classroom To-do List Join our Remind Feed: rmd.at/ussforces