Les 10 - Samenvatting

• Aardrijkskunde
• Middelbare school
• vwo
• Leerjaar 3

Summary

Key words §3.1

Fresh water (zoet water): Water with a low concentration of dissolved salt. Drinking water is fresh water too.

Salt water (zout water): Water with a high concentration of dissolved salt. Sea water for example

Precipitation (neerslag): The different ways water falls back down to earth. For instance as rain, snow or hail.

Evaporation (verdamping): The process of water in liquid form turning into water in gaseous (gas) form..

Condensation (condensatie): The proces of a gas turning into a liquid. When watervapour cools it condenses into tiny drops of water and ice crystals. This is what we call clouds.

Infiltration (infiltratie): process by which water enters the soil (bodem)

Hydrological cycle (waterkringloop): The process by which seawater returns to the sea through evaporation and precipitation, and through groundwater and rivers

Watervapour (waterdamp): The gaseous state of water

Surface water (oppervlaktewater): water that is visible, such as lakes, rivers and seas

Ground water (grondwater): Water that is no longer visible, because it has infiltrated into the rock, and is now underground.

Glacier (gletsjer): Large bodies of ice on mountains as a result of snow falling on the mountains, which accumulates over time

Landice (landijs): Masses of ice which are on land

Accessible water

• Only 0,25% of all water is accessible to us

Waterstress

Water is not equally divided in multiple ways

• Worldwide
• Seasonally
• Locally

Waterstress happens when more water is used than available in an area

The short water cycle!

Hydrological cycle (waterkringloop): The process by which seawater returns to the sea through evaporation and precipitation, and through groundwater and rivers

The long water cycle!

Hydrological cycle (waterkringloop): The process by which seawater returns to the sea through evaporation and precipitation, and through groundwater and rivers

Key words §3.2

Water balance (waterbalans): The amount of water that goes into and out of an area

Useful precipitation (nuttige neerslag): The difference between precipitation and evaporation

Fossil water (fossiel water): Water under the ground that dates back to ancient times

Aquifer (Aquifer): Layer that holds water underground

Renewable water sources (vernieuwbaar water): A source of water that replenishes at the same rate it is used

Non-renewable water sources (Niet-vernieuwbaar water): A source of water that barely gets replenished, or not at all. So if it is used it will eventually run out. Like an aquifer.

Sustainable water management (Duurzaam waterbeheer): A way of using water which only uses renewable water sources.

Water balance

Water balance (waterbalans): The amount of water that goes into and out of an area

Water coming in

Three main ways

• Precipitation (neerslag)
• Rivers
• Fossil water (fossiel water): Water under the ground that dates back to ancient times

Water going out

• Evaporation
• Runoff

Fossil water

• Fossil water (fossiel water): Water under the ground that dates back to ancient times
• Aquifer (Aquifer): Layer that holds water underground
• Most used in dry regions of the world

Sustainable water management

Two ways to achieve sustainable water management

• Make sure more water is coming in from renewable sources
• Make sure less water is leaving an area

Water coming in

Three main ways

• Precipitation (neerslag)
• Rivers
• Fossil water (fossiel water): Water under the ground that dates back to ancient times

Sustainable water management

• Desalination plants (making fresh water from salt water)
• Making water from the air

Water going out

• Evaporation
• Runoff

Sustainable water management

• Decrease runoff by building dams
• Prevent evaporation by using more efficient irrigation
• Genetically modified plants that use less water

Waterbalans interpreteren

Key words §3.3

Hurricane (Orkaan):A tropical storm with windspeeds over 200 km per hour.

Peak discharge (Piekafvoer): The max amount of water going trough a river after a rainstorm. If a flood happens this is the moment.

Soil subsidence (bodemdaling): Sinking of the ground.

Effects of flooding

• Direct effects
• Indirect effects

Effects of flooding

• Direct effects
• Indirect effects

Loss of electricity

Loss of water from the tap

No more infrastructure

No more new food in the supermarket

Measures against flooding

Short-term:

• constructing dykes, dams and retention basins;
• monitoring the weather in the entire river basin;
• educating and training citizens (for example, evacuation practice etc.);
• safeguarding drinking water and food after flooding.

Measures against flooding

Long-term:

• making room for the river: no longer locking up the river between dykes but giving back the flood plains to the river (also upstream);
• reducing the enhanced greenhouse effect: this will help prevent the sea level rising and extreme weather;
• making a location policy, where people are moved or banned from risk areas as much as possible.

Peak discharge (Piekafvoer)

so it is the max amount of water going trough a river after a rainstorm. If a flood happens this is the moment

Risk factors

• River and coastal plains. As much as 70 percent of the world population lives along rivers or close to the coast. Often in these low-lying areas there is the threat of flooding.
• Areas at the foot of a mountain with a rocky surface. During heavy rainfall, there is almost no water that can sink into the soil, so all the water goes into the river at the same time. The bed of the river is often too small to absorb this peak discharge.
• Areas where the melting of the snow coincides with heavy rainfall in the summer.
• Areas where tropical hurricanes are common. A hurricane causes heavy rainfall and blows the water against the coast, making the sea level much higher.
• Areas where deforestation is taking place upstream. In heavy rainfall there is no more forest that can hold the water for a while like a sponge. As a result, the water immediately flows into the river.
• Areas which have been fossilised due to urban development.
• Areas with soil subsidence due to the pumping up of groundwater.

Economic water shortage

If there is not enough money to get enough water to the people of an area

For instance if there are no pipelines to bring water to people

Physical water shortage

If there is just not enough water in an area

Dealing with little water

Three options:

• Hold on to the water you have
• Make more water
• Use less water

How to manage too much water (the Dutch way)

Three step strategy

• Store (vasthouden)
• Save (bergen)
• Drain (afvoeren)

Wat is de overeenkomst tussen verstening van de stedelijke omgeving en ontbossing als we kijken naar overstromingen?

Wat is het verschil tussen vasthouden en bergen in de drietrapsstrategie?

In landen die veel gebruik maken van aquifers voor hun water is er vaak geen sprake van duurzaam waterbeheer. Leg aan de hand van het plaatje uit waarom dit komt, en in welk geval duurzaam waterbeheer wel mogelijk zijn met gebruik van aquifers.