Vegetation
Heathland is defined by characteristics such as vegetation dominated by plants of the Ericaceae (heathers) family, few trees and sandy acidic soils. Heathland is a "plagio climax" vegetation type. This simply means that it originated through, and is maintained by some human activity. If that activity should increase then the plagio climax vegetation will progress towards a true climax vegetation. In Ashdown Forest there are plants such as heather, dwarf gorses and cross-leaved heath, some areas of scattered trees and scrub, areas of bare ground, gorse, wet heaths, bogs and open water. Heathland supports numerous species the most common being invertebrates such silver-studded blue butterflies, the raft spider (UK’s largest spider) and bog bush crickets. It is also home to the adder (Britain's only poisonous snake) and lizards.
Land use
Farming
Man has lived and worked in Ashdown Forest for 5,000 years, with Iron working during the Roman Period and Saxon Farming, however the forest took on its role as an area of enjoyment in the 11th century, when it was set up as a hunting ground for the Crown and used for Rabbit farming.
Leisure and recreational activities
Ashdown Forest is the largest public access space in south-east England, and the largest area of open, uncultivated countryside.
The Forest has retained its celebrated tranquillity and sense of openness. The commons are freely open to the public, who are attracted by the large, elevated expanse of unspoiled heaths, and woodlands where they may walk, picnic or simply sit while taking in the glorious views. Various bye-laws passed by the Conservators help protect the Forest environment for the public good, prohibiting such activities as, for example, mountain biking, off-road driving of motor vehicles, camping, and the lighting of fires.
Ashdown Forest is very popular with walkers. Two long-distance footpaths, the and cross the forest and meet near Old Lodge. The Wealdway passes through Five Hundred Acre wood and hundred of the Winnie-the-Pooh stories.
There are 82 miles (132 km) of tracks on the Forest that may be ridden by horse once an annual permit has been obtained from the Conservators.
The Forest, with its attractive landscapes, vistas and hills, is a popular destination for road cyclists, races and cyclosportives such as the Hell of the Ashdown.
River Features
Source
Source is the beginning or start of a river. As the river moves through the upper course it cuts downwards. The gradient here is steep and the river channel is narrow. Vertical erosion in this highland part of the river helps to create V-shaped valleys, interlocking spurs, rapids, waterfalls and gorges.
- As the river erodes the landscape in the upper course, it winds and bends to avoid areas of hard rock. This creates interlocking spurs, which look a bit like the interlocking parts of a zip.
- When a river runs over alternating layers of hard and soft rock, rapids and waterfalls may form.
Meanders
In the middle course the river has more energy and a high volume of water. The gradient here is gentle and lateral (sideways) erosion has widened the river channel. The river channel has also deepened. A larger river channel means there is less friction, so the water flows faster:
- As the river erodes laterally, to the right side then the left side, it forms large bends, and then horseshoe-like loops called meanders.
- The formation of meanders is due to both deposition and erosion and meanders gradually migrate downstream.
- The force of the water erodes and undercuts the river bank on the outside of the bend where water flow has most energy due to decreased friction.
- On the inside of the bend, where the river flow is slower, material is deposited, as there is more friction.
- Over time the horseshoe become tighter, until the ends become very close together. As the river breaks through, e.g. during a flood when the river has a higher discharge and more energy, and the ends join, the loop is cut-off from the main channel. The cut-off loop is called an oxbow lake.
Oxbow lake
In the animation above, upstream a large bend becomes a horseshoe and is eventually cut-off to become an oxbow lake. Downstream the river is eroding its outer bank and depositing on its inner bank to create a new meander.
Floodplains
The river now has a wide floodplain. A floodplain is the area around a river that is covered in times of flood. A floodplain is a very fertile area due to the rich alluvium deposited by floodwaters. This makes floodplains a good place for agriculture.
Some other river features are-
Watershed - the edge of highland surrounding a drainage basin. It marks the boundary between two drainage basins.
Confluence - the point at which two rivers or streams join.
Tributary - a stream or smaller river which joins a larger stream or river.
Mouth - the point where the river comes to the end, usually when entering a sea.
Fieldwork
In our mini- group we measure river cross - section and speed of the river. Our site was C.
River Cross section
We first find out the width of the river which was 1m 15 cm. To do this we stretched a tape measure from left bank to right bank. Secondly two of us were holding tape at each bank while the third person went in the water with a metre stick. We were taking the measurement in every 10 cm. Lastly the 4th person was recording the result in the booklet.
The result was quite hard to get because the river was fill of rocks. So we’ve got different depths result from different distance. But they were quite close but there weren’t any specific pattern.
River velocity (speed)
It was hard to get result because there was hardly any water in the river. So we dropped a dog biscuit and timed it for 1 minute and observed how much distance it can flow in 1 minute. We repeated it twice and each time 10 cm stretch. We observed it and measured the distance using tape. Here’s the result-
The results are pretty much accurate. As we were moving towards the site D, the river was less deep.
Niagara Falls
Niagara Falls is located in western New York state and southeastern Ontario, Canada. There are falls on both sides of the Niagara River, in Canada as well as the United States. The Canadian Horseshoe Falls plunge 170 feet down. The American Falls plunge 100 feet. This beautiful waterfall is a popular tourist , bringing millions of visitors to the area each year. It also serves a more practical purpose in providing electricity to Ontario and New York.
Creation
Niagara Falls is approximately 12,000 years old. The falls were formed when melting glaciers began to form the large freshwater lakes now known as the Great Lakes. The water in Lake Erie ran downhill toward Lake Ontario, forming a river. This river crosses a ridge known as the Niagara Escarpment. The area where this river falls over the cliffs of the Niagara Escarpment is known as Niagara Falls.
Erosion
As water rushed over the Niagara Escarpment, it eroded the rock underneath, forming the Niagara Gorge. Until the 1950s, Niagara Falls eroded more than 3 feet of the escarpment each year, slowly moving the falls back. Water diversion programs have since reduced the erosion significantly. The Encarta encyclopedia reports that the falls now recede only about 1 foot every 10 years.