Topic: What factors affect the amount of precipitation?

Target group

High school / technical high school student (basic scope)

New core curriculum

General requirements

II. Skills and application of knowledge in practice.

3 . Identifying the relationship between individual elements of the geographical environment (natural, socio‑economic and cultural).

4 . Formulating theorems about basic regularities concerning the functioning of the geographical environment.

III. Atmosphere: climatic factors, distribution of air temperature, atmospheric pressure and precipitation, general atmospheric circulation, synoptic map, climatic zones and types of climates.

Student:

3 ) explains the mechanism of atmospheric circulation and distribution of atmospheric precipitation on Earth.

The aim of education:

The student will learn what factors affect the amount of precipitation

Criteria of success

• characterize the main factors that determine the amount of precipitation on Earth;

• read the average amount of precipitation (annual, semi‑annual, monthly, etc.) for the selected place on Earth from the map showing the average distribution of precipitation;

• explain the reasons for the variation in the amount of annual precipitation in different regions on Earth.

Key competences

• communication in the mother tongue;

• communication in foreign languages;

• mathematical competences;

• digital competence;

• learning to learn.

Teaching aids

• computers (or tablets) with internet access;

• multimedia resources available under “What factors affect the amount of precipitation?” in the e‑textbook;

• general geographical map of the world (a wall map, digital map or an atlas);

• interactive whiteboard/blackboard, marker/chalk.

Methods / forms of work

• the problem‑solving method: discussion;

• the expository methods: presentation;

• programmed learning: via computer, e‑textbook;

• practical learning: exercises on the subject, case study;

• individual activity, activity in groups, and collective activity.

Lesson plan overview (Process)

Introduction

1. In class, the teacher determines the purpose of the lesson, informing students about its planned course.

2. The teacher mentions and records on the board the factors affecting the amount of rainfall on Earth, such as:

• atmospheric pressure;

• distance from water reservoirs;

• height above sea level;

• landform;

• sea currents.

Implementation

1. The trainer initiates a brainstorming, the purpose of which is to determine why and how these factors affect the amount of rainfall. The teacher approaches students' proposals by indicating those that correctly determine the impact of a given factor on the amount of rainfall.

2. The teacher divides the class into groups (maximum 4‑5 people in the group). Each group on the basis of rainfall sum distribution maps and a hypsometric map of Poland located in the abstract gallery is to determine which main factors affect the amount of rainfall in one of the towns indicated by the teacher. At the end of this part of the lesson, one person from each group presents the lessons learned in the class forum.

3. The teacher sums up this part of the lesson and, together with the students, estimates the range in which the sums of precipitation in towns located on the territory of Poland are located.

4. The lecturer presents a map of the distribution of annual precipitation totals on Earth and discusses it briefly. Then he asks students to compare the amount of rainfall totals in Poland with rainfall sums in selected places on Earth. The class analyzes the potential causes of the differences.

5. Students individually or in pairs follow the instruction: „What factors affect the amount of precipitation??” in e‑textbook and interactive exercise. While performing these tasks, students use the map discussed previously by the teacher. In the case of interactive exercise, they can also use the general world map of the world if necessary. The teacher checks the solutions on a regular basis and helps students who have difficulties with tasks.

6. The teacher presents the curiosities attached to the lessons in the e‑textbook and initiates a discussion on the class forum regarding the differentiation of absolute humidity on the Earth.

Summarized

There is a summary of the lesson, during which students can ask questions and complete their notes.

The following terms and recordings will be used during this lesson

Terms

Texts and recordings

What factors affect the amount of precipitation?

Spatial differentiation of absolute humidity on Earth depends on many geographical factors. Absolute humidity decreases as the latitude increases, which is a result of lower air temperature. The same way humidity decreases with altitude. There is extreme low humidity in the Tropics. It is related to how atmosphere circulates there. In addition, air humidity decreases the further away we are from the large water reservoirs. The amount of atmospheric precipitation in a given area is proportionally dependent on air humidity. However, there are also other important factors affecting the diversity of precipitation on Earth.

Factors affecting the amount of precipitation on Earth:

• atmospheric pressure and the related air circulation – higher precipitation is associated with low pressure systems;

• distance from water reservoirs – the amount of precipitation decreases the further from the sea;

• height above the sea level – higher altitude means more precipitation – however, it applies only up to a certain height, then the precipitation begins to decrease (precipitation inversion);

• terrain– windward slopes usually receive more precipitation than leeward ones, less precipitation occurs in the valleys of the hills (rain shadow);

• sea currents – coast with warm sea currents are characterized by heavy precipitation, and those with cold sea currents are very dry.

As a result, the highest precipitation occurs in the equatorial zone, in Southeast Asia and on the southern slopes of the Himalayas. The least rainfall is recorded in the Tropics, the Antarctic and Arctic Circle and within continents, e.g. in central Asia.

The lowest annual amount of precipitation is recorded in the Atacama Desert in Chile. This area is characterized by a very small amount of precipitation, less than 50 mm per year, and in many regions below 10 and even 1 mm (around the city of Arica). The central part of Atacama is called a true desert, since no precipitation has ever been recorded since the measurements started.

• Geographical factors affect the variability of the amount of precipitation in different places around the world,

• the amount of precipitation on Earth is influenced by such factors as: atmospheric pressure, distance from water reservoirs, height above the sea level, terrain, sea currents.