Monday 3rd March

DO NOW: Complete these sentences…

• In areas of high or steep relief there tend to be more/less roads.

• Settlements tend to occur in areas where there is steep/flat relief.

• Port developments occurs in areas where the water channel is shallow/deep.

• Native forests are more common in areas where the relief is steep/flat.

What words are being used instead of concentrated / sparse?

Level 1 Geography

Skills – 1.5: Patterns

Due: Friday 7th March

Homework for Week 6:

Checking Week 5’s Homework

Learning Intention:

- To be able to describe how the process of precipitation formation creates an unequal pattern of access to safe water

Identifying Patterns

The Precipitation Process

Precipitation is the falling products of condensation – rain, snow, hail

What makes precipitation?

– on your group paper, write or draw how you think precipitation is created

Are we right? Let’s find out…

Convectional Rainfall

• Come and get your group’s resources

• Read the instructions carefully. Ask for help if you need it.

• Complete each task. Check your work as you go.

• You must complete this work today.

Air pressure: Highs and Lows

High Pressure

As the air rises, it cools and falls back to the earth’s surface creating a high pressure area.

High Pressure

Low Pressure

Earth’s Surface

Equator

These are called air convection currents

Tropic of Cancer Tropic of Capricorn

Earth’s Surface

• Create a flow diagram to explain convection currents

Why do you think the areas are called high and low pressure zones

evaporation

Water condenses

Rainfall

Convectional Rainfall

1

2

34

Sun heating the earth

Ocean (or land)

• Create a flow diagram to explain convection rainfall

• Add in the relevant convection currents information. (convectional rainfall is called this for a good reason )

Convectional Rainfall occurs due to convection currents. Convections currents are when something rises because it heats and the falls because it cools. Heat rises and the further it rises the more it cools. When it cools enough, it falls back to earth.

The Earth is not heated equally by the sun. At the Equator, which receives the most sun's heat, hot air rises creating a zone of low pressure. The air spreads towards the tropics, cools down and descends. Much of the moisture is lost now as rain. As these dry winds sink, they create areas of high pressure where most of the deserts are found - at the Tropics of Cancer and Capricorn. An example of a desert formed by this is the Sahara.

Convectional Rainfall

Use an atlas to compare the following maps:

- Precipitation around the world

- Deserts of the world- Climatic regions- Access to safe water- World population

distribution

What relationships are there?

Average Precipitation (mm) per day

World Deserts

Climatic Regions

Tropical

Deserts

% of Population with Limited Access to Safe Water

World Population Distribution

Precipitation formation is one process that helps to create the unequal pattern of access to safe water because some areas get more rainfall than others.

For example precipitation is created by the heating and cooling of the earth. Firstly, the sun heats the earth and evaporates moisture. This heating is concentrated at the equator. At the equator, the heated air rises carrying evaporated moisture, creating a low pressure zone. As the air rises, it cools and moisture condenses. This condensation finally precipitates and falls back to earth. The cool air continues to sink, but by this stage it is very dry as all the rain has fallen. This creates an area of high pressure just above and below the tropic of Cancer and Capricorn. This is where most of the deserts are found, for example the Sahara in Africa, the Gobi in China, the Great Sandy Desert in Australia, the Thar in India.

This process has led to the deserted areas being with less rainfall _______mm/yr. These areas have __________% of people without access to safe water. The exception is Australia whose population is mostly situated around the South East coast where there is higher amounts of rainfall than the North West inland deserts.

Therefore areas of high %’s without access to safe water are areas that have very little precipitation eg Sahara desert in Africa which has _____% of people without access to safe water.

Types of Rainfall: Orographic

Moist air forced to rise

Rain shadow on leeward side

Air warms as it descends

Air cools as it rises

Rain Dry

Reflection

• One question I still have about today’s lesson is…