My Dubai Flashcards
What is geography
Geography is study of earth
Describe what happens in each stage of the water cycle:
-Evaporation -Condensation Precipitation -Surface Run Off Transpiration
What are the main characteristics of the three major rocks types:
Igneous Sedimentary Metamorphic
How does rock type affect the landscape?
Soft rock erode faster and hard rock erode slowly
Describe and Explain how a river changes from source to mouth:
-Depth -Width -Gradient -Velocity -River Discharge
What is erosion? Name and explain the four types.
Erosion by Water Liquid water is the major agent of erosion on Earth. Rain, rivers, floods, lakes, and the ocean carry away bits of soil and sand and slowly wash away the sediment. Rainfall produces four types of soil erosion: splash erosion, sheet erosion, rill erosion, and gully erosion.
Explain the formation of Upper Course Landforms - Waterfalls
In the upper course there is more vertical erosion . The river cuts down into the valley. If there are areas of hard rock which are harder to erode, the river will bend around it. This creates interlocking spurs of land which link together like the teeth of a zip.
What is deposition? Why does it happen?
Deposition is the laying down of sediment carried by wind, flowing water, the sea or ice. Sediment can be transported as pebbles, sand and mud, or as salts dissolved in water. Salts may later be deposited by organic activity (e.g. as sea shells) or by evaporation.
Explain the formation of Middle Course Landforms - Meanders
The formation of meanders is due to both deposition and erosion and meanders gradually migrate downstream.
Explain the formation of Lower Course Landforms-Floodplains 6 and Levees
A floodplain is the area around a river that is covered in times of flood. This is a large, flat area of land that is formed by erosion and deposition.Erosion of the outer bends of a meander will gradually wear down and flatten the land on either side of the channel.When the river overflows its banks during a flood, the river will leave the channel and flow across the neighbouring land. Every time that a river floods its banks, it will deposit more silt or alluvium on the flood plain. Over time, the flood plain will become wider due to erosion and deeper due to deposition.
A levee is a raised bank formed on the banks of a river, in the lower course.
Levees are formed by the repeated flooding of the river. When the river floods, during periods of high energy, the water and the load it is carrying will leave the channel.
Due to the drop in energy caused by friction, the biggest, most coarse material will be dumped close to the river banks. With repeated flooding, this will continue to build up the levee over time.
Name the major river in Bangladesh?
Sangu and Halda
What are the causes of River Flooding in Bangladesh?
Tectonic UPLIFT IN THE HIMALAYAS MEANS THAT SEDIMENT EROSION INCREASES, CLOGGING UP THE CHANNEL WITH ERODED SEDIMENT
Explain how Dams & Reservoirs, River Straightening and Embankments prevent river flooding (HARD ENGINEERING)
Straightening the river speeds up the water, so high volumes can pass through an area quickly, therefore reducing the chances of a flood.
Explain how Flooding Warning Systems and Floodplain Zoning prevent river flooding (SOFT ENGINEERING)
putting building restrictions in place on floodplains that are at risk of flooding.
What is the difference between Hard and Soft Engineering?
A hard engineering approach involves building structures, such as groynes, sea walls or rock armour, to protect the coastal area. A soft engineering approach works with natural processes.
