The Clifton Suspension Bridge

The world famous Clifton Suspension Bridge is a suspension bridge, which opened in 1864. Spanning the Avon Gorge and the River Avon. The Clifton Suspension Bridge was designed by the famous Victorian engineer Isambard Kingdom Brunel.

Work actually began in 1831, and by 1843, with only the towers completed, the project was abandoned. 

Brunel died aged only 53 in 1859, but the Clifton Suspension Bridge was completed as his memorial. 

Designed in the early 19th century for light horse drawn traffic, it still meets the demands of 21st century commuter with 11-12,000 vehicles crossing it every day.

Dimensions
Clearance:	75 m above high water level
Dip of chains:	21.34 m
Height of towers:	26 m above deck
Overall length:	412 m
Overall width:	9.45 m
Span:	214.05 m

Aral sea

Images of the Aral sea between Kazakhstan and Uzbekistan, taken in 1973, 1987, 1999, 2004, 2007 and 2009, show how it has virtually disappeared after the rivers that fed it were diverted by irrigation projects. The Aral sea was once one of the largest lakes on earth.

Favelas

A favela is the term for a slum or a shanty town in brazil. They are mostly found on the outskirts of urban areas. Most of the favela is on a very steep hill, with many trees surrounding it. 

The people living in the favelas are the poor, and the rich people live in the city. And the vast majority of the population is black.

Most of the buildings in favelas are made out of cheap materials, like wood, plastic, glass and scrap material. 

The people usually build their houses themselves and invite their friends to help them build. 

The favelas are illegal, because the people do not pay tax. Despite the attempts to cleanse Rio de Janeiro and São Paulo of favelas, the poor population grew at a rapid pace. 

In 1969, there were approximately 300 favelas in Rio de Janeiro; today there are twice as many. In 1950, only 7 percent of Rio de Janeiro's population lived in favelas, nowadays this number has grown to 19 percent or about one in five people living in a favela. 
Census data shows that in 2010, about 6 percent of the population lived in slums in Brazil. 

Crime (and especially the cocaine trade) is common in favelas, as many of the people have no other way to make money. The cocaine trade has affected the favelas. The favelas tend to be ruled by drug lords. Police in Rio de Janeiro are seeking to take back control of many of the cities main favelas from drug gangs before playing host to matches in the 2014 World Cup and the 2016 Olympic Games.

The photo above shows a resident who was shot and lies on the ground as others help him during a police operation at a slum in Rio de Janeiro

Regular shoot-outs between traffickers and police and other criminals, lead to murder rates in excess of 40 per 100,000 inhabitants in the city of Rio and much higher rates in some Rio favelas. 

The favela Rocinha (69,300 - number of inhabitants in 2010, 150,000 – estimated approximate true number of inhabitants of Rocinha) is the largest favela in Rio de Janeiro and in Brazil, and is located in Rio de Janeiro's southern part. Rocinha is built on a steep hillside overlooking Rio de Janeiro, and is located about one kilometre from a nearby beach.  

Las Vegas and the desert water pipeline

The city of Las Vegas wants to pump up to 300 billion litres of water a year out of the Nevada desert and transport it 480 kilometres south to the thirsty city.

In Las Vegas, where the population had been doubling every ten years, planners had an idea. What if there were a way of pumping the water towards Las Vegas? 

Water was ever an issue in the American west. For 100 years, Nevada and other south-western states have shared the waters of the Colorado river (and Lake Mead). 

But Lake Mead begins to decline in the past decade as Las Vegas expands. 

The city, which for years has been drawing more water from its Lake Mead reservoir than has been flowing in, could be at serious risk of going dry in 20 years, said Pat Mulroy, the manager of the Southern Nevada Water Authority. 

The city needed a new plan. When you have got a community of 2 million people and it is 90% reliant on the Colorado river you have to have a contingency plan, she said. The Water Authority has spent 79 million dollars to buy up water rights and they wants to pump up to 300 billion litres of water a year. A study last summer warning the pipeline would lower water tables in some valleys by up to 60 metres over the coming decades. Smaller springs would dry up completely and the animals that depend on them would die off.

Water in the Netherlands

Section 16  - Water in the Netherlands

40% of the Netherlands is below sea level.

The struggle against the sea / water (the fight against).

New landscapes are created.

• terps = protection against the rising sea level.

• dikes = initially only used as protection, later more offensive, to reclaim land. For example salt meadows (= kwelders) outside the dikes were reclaimed.

Polders

Water level is regulated. 

Types of polders:

• - sea polders
• - peat polders
• - “droogmakerijen”

Problem = outside water can seep through the dikes into the polder.

More space for water

In the past = ‘watermanagement’ = to keep the land dry.

In the future = ‘watermanagement‘ = water will be retained, areas will be deliberately flooded.

Why ? Climate change – (1) summers drier, winters wetter. (2) sea level is rising.

Space for rivers

• to keep the land dry water was discharged by (1) digging ditches and canals or (2) strainghtening out streams (3) pumping stations.
• in the future water will even be retained, certain areas will be deliberately flooded.

A permanent coast

• dikes must be reinforced due to the rising sea level.
• sand replenishment = due to erosion.

Dehydration

• dehydration (verdroging) drop in the ground water level.
• extinction of certain vegetation = drought.
• water table has dropped by 30 cm. 

Why?

1. farming (water extraction for irrigation)
2. drinking water (water extraction)
3. industry (water extraction)
4. asphalting = less water can subside into the underground (deceased infiltration / seep through) 

Managing and Reducing Losses from Water

The atmosphere

The atmosphere is divided into five layers. It is thickest near the surface and thins out with height until it eventually merges with space.

1) The troposphere	The troposphere is the first layer above the surface and contains half of the Earth's atmosphere. Weather occurs in this layer. Weather in this layer affects our daily life.	Between 7 to 14 kilometres.	The higher, the colder.
2) The stratosphere	Many jet aircrafts fly in the stratosphere because it is very stable. Also, the ozone layer absorbs harmful rays from the Sun.	Starts at 14 to 50 kilometres.	The higher, the hotter.
3) The mesosphere.	Meteors or rock fragments burn up in the mesosphere.	Between 50 to 85 kilometres.	The higher, the colder.
4) The thermosphere.	The thermosphere is a layer with auroras. It is also where the space shuttle orbits.	Between 85 to 640 kilometres or higher.	The higher, the hotter.
5) The exosphere.	The atmosphere merges into space in the extremely thin exosphere. This is the upper limit of our atmosphere.	640 kilometres or higher.

The water cycle

Water is essential for life as we know it. The water cycle is the cycle that water goes through on Earth. It makes the rain, clouds, and most of our weather. 

The water cycle, also known as the hydrologic cycle, describes the continuous movement of water on, above and below the surface of the Earth. Water can change states among liquid, vapour, and solid at several places in the water cycle.

The sun, which drives the water cycle, heats water in oceans and seas. Water evaporates as water vapour into the air. Rising air currents take the vapour up into the atmosphere where cooler temperatures cause it to condense into clouds. Air currents move water vapour around the globe, cloud particles fall out of the sky as precipitation. Some precipitation falls as snow or hail.

Most water falls back into the oceans or onto land as rain, where the water flows over the ground as surface runoff. A portion of runoff enters rivers in valleys in the landscape, moving water towards the oceans. Not all runoff flows into rivers, much of it soaks into the ground as infiltration. Some water infiltrates deep into the ground and replenishes aquifers, which store freshwater for long periods of time.


Over time, the water returns to the ocean, where the water cycle started.

The water cycle

1. - First, water on the earth, in lakes, in oceans and in the sea is evaporated by the heat from the Sun.
2. - Excess water from plants is also absorbed into the atmosphere, this process is called transpiration.
3. - Then, water collects as water vapor in the sky. This makes clouds.
4. - Next, the water in the clouds gets cold. This makes it become liquid again. This process is called condensation.
5. - Then, the water falls from the sky as rain, snow, sleet, or hail which is called precipitation.
6. -The water then collects into lakes, oceans, or aquifers. From there, it evaporates again and continues the cycle.