Compare the causes of two contrasting floods. (Boscastle and Thailand) I am going to compare the physical and human flooding causes for an MEDC; the UK and an LEDC; Thailand. The Boscastle Floods, in Cornwall occurred on August 16th 2004. Between July and December of 2011, Thailand also suffered large amounts of flooding. There were a number of physical factors causing the Boscastle floods.
Throughout the afternoon an unprecedented amount of rain fell, estimated at over 1.400 million litres in just 2 hours, nearly 200,000 litres a second. The rainfall quickly made its way into rivers that rose at an alarming rate as they flowed through Boscastle. 9 minutes later a flood watch was issued. 3 hours and 1 minute later at 15:00 the first of many power cuts where caused by lightning, 30 minutes later, the river valency began to flood. 16 minutes later there was a reported rise of 2m in one hour.
Furthermore, river cliffs are also created due to the rock type. The river bank of the Tees is made up of soft, unconsolidated boulder clay which means it is easily eroded by the flow of the river. This results in a steep river cliff as the flow of the river is constantly eroding the soft rock. In addition, another landform of fluvial erosion that can be found along the River Tees are ox bow lakes. An oxbow lake is a U-shaped body of water that forms when a wide meander from the main stream of a river is cut off, creating a free-standing body of water.
The towns there are being threatened and damaged, and there have been many villages to be washed into the sea along this stretch of the eastern coastline. Here are some photographs to back up this point further: (Sources 1, 2 & 3) Why is the coastline eroding at such a fast rate? The Holderness coast is made up mostly of clay and chalk so naturally the coast is likely to erode faster than areas of coastline made of hard rock. However, at Holderness, the rock is much weaker and gets eroded at a much higher rate. Yet, in some places, groynes have been put in place to trap sediment and protect these areas of weak coast, largely the areas with major towns.
Also, as soft rock is being eroded at a faster rate than hard rock, steps in the riverbed are created, causing rapids. As the soft rock is being eroded, undercutting of the harder rock can occur until it collapses, causing a plunge pool and a waterfall. The land in the middle course is much flatter than the mountainous upper course because the middle course is closer to the sea level, away from mountains. Because the land is flatter, lateral erosion occurs, making the channel much wider. As a meander forms, an inside bend has less energy, so deposition occurs, causing a slip-off slope.
The flooding was very unpredictable and could cause mass destruction. Too little rain and they could end up with famine, too much and everything was destroyed. Menes was one of the great pharaohs that this documentary talks about. He is credited for uniting Upper and Lower Egypt and is the founder of the First Dynasty. He built the first damn to protect the city from the flooding which required extreme labor.
DEVASTATING WALKER RIVER FLOOD! In the last couple of days California and Nevada have suffered the worst floods in living memory! Normally the river flows at 650 cubic feet per second, however in the past week the river flowed more than twice that and at a devastating rate that destroyed everything in its path, including lives of two people. The flood also inundated 63,000 acres of land and cost millions in damage and additional costs due to disruptions in travel and business. The Walker River begins at a confluence where the tributaries of the West and the East Walker Rivers meet.
In the upper course, which is on high land, we see features such as the V-shaped valleys, interlocking spurs, rapids, waterfalls and gorges forming. This is because there is an increased amount of vertical erosion and weathering occurring. As the river heads downstream futures such as wider, shallower valleys, meanders and ox bow lakes occur . In the lower course flat-bottomed valleys, floodplains and deltas are usually the common characteristics. This is due to the fact that limited to no vertical erosion can take place.
Every year due to the high demand for vacation cruises, the amount of pollution dumped into the oceans are staggering. While efforts “could” be made to stem this problem, they are not, because of the high costs involved. If the cruise lines dump their waste beyond 25 miles, then the legal issues become null and void. “By international law, countries may regulate oceans for three miles off their shores. International treaties provide some additional regulation up to 25 miles offshore.
The effect of Hurricane Katrina on New Orleans was extremely severe, resulting from one of the most deadly natural disasters in U.S. history. By August 30th, 2005, one day after the Category 4 storm made landfall, about 80 percent of the city of New Orleans, was flooded with some parts of the city under 20 feet of water. The flood was caused by several levees breaches, which most people didn’t believe it could breach, due to a combination of a powerful storm surge, strong winds and excess water in the bodies of water surrounding the city. After reading the author’s response, her curiosity was based on her belief that the delayed response time was due to racism. She first noticed when watching the T.V.