Factors affecting coasts

The four main factors affecting coasts are Geology, vegetation, sea-level changes and human activities.

Geology: Depending of which material the coastline is made of can affect the time of erosion, and will erode much quicker if the coast is weak and made of rocks such as clays and sand, whereas if the coast is made of a more resistant, harder rock it will not erode so quickly.

Vegetation: Helps the protect the coastline, by holding it together with the roots from plants.

Sea-level changes: Low lying coasts are being drowned by rising sea-levels caused by global warming, this is a large problem since the worlds most densely populated areas are.

Sea-level changes: Low lying coasts are being drowned by rising sea-levels caused by global warming, this is a large problem since the worlds most densely populated areas are.

Coastal Enviroments

Marine processes

Waves do most of the work of marine processes. They erode, transport and deposit material. Waves are created from wind. The size of the wave depends on: strength of the wind, how long the wind blows for (duration) and the fetch.

Transportation (longshore drift)

Longshore Drift: This is the process of waves moving (transporting) material (load) along a coastline.
Swash: The waves breaking and traveling up the beach carrying load. Waves will break and the swash will travel in the direction of the wind.
Backwash: The waves returning to the sea with load. Waves will take the shortest possible route back to the sea (gravity).
Longshore drift only happens when the waves hit the beach at an angle. It is the process of the swash transporting material up the beach at an angle and the backwash returning directly under the force of gravity that causes material to be transported along the beach.

Prevailing (or dominant) Wind: This is the direction that the wind normally hits a coastline.

Groynes: Groynes are wooden or concrete fences (walls) placed out into the sea to stop longshore drift happening.

Presentation on hydroelectric energy.

Our slide show, I have uploaded it to a website for easy viewing.
http://snack.to/btme7f3c

Energy - Renewable Vs Non-Renewable

Sources of energy

Energy is one of the requirements necessary to run day to day activities. There are many different sources of energy that are naturally available throughout the world in different forms. Depending with energy regeneration, energy can be categorized into two main different sources which are renewable and non renewable sources.

Renewable sources of energy

Renewable sources of energy are obtained from different natural sources. The main common sources are sunlight, wind, tides and thermal.  Energy is acquired from these sources using devices such as solar panels (for energy from sunlight) and wind turbines (energy from the wind).

Pros of renewable sources of energy

1. Renewable sources of energy are renewable and easily regenerated. This is unlike fossil fuels which are perishable once used.
2. Renewable source of energy such as solar produce clean energy that does not pollute the environment. This is because no burning is required during usage of the energy.
3. Most importantly, renewable energy are available everywhere throughout the world thus there is no chance of the sources becoming depleted in future. For example, solar energy is everywhere as the sun will always be there every day.
4. Maintenance cost needed to install and use the renewable energy is relatively cheap. Solar energy can be trapped easily and used for domestic needs.
5. Renewable sources of energy boost economic growth and increase job opportunities. This includes electrical energy which is used to run many industries.

Cons of renewable sources of energy

Every set of energy has its own drawbacks once introduced to the ecology. Some of these limitations include

1. Difficult to produce the energy quantity that is equivalent to that produced by nonrenewable fuels
2. Technology required to trap renewable energy is costly. Setting of dams requires high initial capital to construct and maintain
3. Most renewable sources of energy are affected by weather thus reducing their reliability. For example, hydro generators need constant rainfall that will overflow the dams, wind turbines only rotate if there is wind of a given speed.

Nonrenewable sources of energy

Nonrenewable sources of energy have continued to produce constant energy throughout the world. This is because of their high availability. Sources of nonrenewable energy can be attributed to natural sources that are not regenerated once the source is depleted. Sources include fossils fuels such as coal and petroleum products e.g. natural gas and diesels.

Pros of nonrenewable sources of energy

Some such as natural gas burns without any soot hence less environmental pollution.

1. Most nonrenewable sources of energy are easy to transport from one area to another. For example petroleum oils which can be transported via pipes.
2. Cost of producing nonrenewable energy is low since they are naturally available. Furthermore they are cheap to transform from one form of energy to another.
3. Most of this energy sources are abundantly available in different areas. Their availability is not affected by climatic condition.

Cons of nonrenewable sources of energy

1. Produce harmful green house gases which contribute global warming. Coal once burnt produces carbon dioxide harmful to the environment.
2. Once they are depleted they cannot be replaced making them expensive to obtain.