Geography knowledge is necessary for the seventh grade, and what are the knowledge points that must

1.The Earth is a sphere. The average radius of the Earth is 6,371 kilometers, the surface area is 100 million square kilometers, and the circumference of the equator is about 40,000 kilometers.

On the globe, the circle that circles around the globe in the east-west direction is called the parallel. The equator is the zero degree latitude on a globe. The latitude north of the equator, north latitude, with "n" as the code name; The latitude south of the equator is called southern latitude, and the "s" is used as the code name.

The North and South Poles are 900n and 900s, respectively. All the weft wires are circles and can be called weft coils. The length of the weft coil is long and short, the equator is the longest, and gradually shortens towards the poles, and finally becomes a point.

The parallels all indicate the east-west direction.

2.The equator is the longest parallel on Earth. It is at an equal distance from the poles and divides the earth into two hemispheres, the north and the south.

3.All the meridians are semicircular, all of equal length, and all indicate the north-south direction.

4.The zero degree meridian on the globe is called the prime meridian. From the prime meridian to the east and west, each divided into 1800, the east of 1800 belongs to the east longitude, and it is customary to use "e" as the code; The 1800 in the west belongs to the west longitude, and it is customary to use "w" as the code name.

5.Internationally, it is customary to use the warp coils of 20ow and 160oe as the boundary between the eastern and western hemispheres. Because this warp coil essentially passes through the ocean, it avoids dividing some countries in Europe and Africa into two hemispheres.

6.The purpose of drawing graticules on globes and maps is to determine the location of any point on the earth's surface.

7.The direction of the Earth's rotation is from west to east, and the time of one rotation is one day. As the Earth rotates constantly, the Earth's surface produces the phenomenon of day and night and the difference in time.

8.The direction of the Earth's revolution is from west to east, and the time it takes to complete one revolution is one year. The orbital plane of the Earth's revolution is always at an angle to the Earth's axis, and the North Pole is always pointing near the North Star. Due to the rotation of the earth, there are changes in the seasons.

9.According to the distribution of solar heat on the earth's surface, the earth's surface is divided into five zones: tropical, north temperate, southern temperate, northern and southern arctic zone. The dividing lines are the Tropic of Cancer and the Arctic and Antarctic Circles.

10.Characteristics of the five belts: tropical - hot all year round, with direct sunlight; Temperate zone - four distinct seasons; Cold zone - cold all year round, with polar day and polar night phenomena.

11.The three elements of the map: scale, direction, and legend.

12.There are three forms of expression of scale: literal, numeric, and linear.

The size of the scale is related to the details of the map sheet: the smaller the area drawn on the map, the more detailed the content to be represented, and the larger the scale should be; Conversely, the smaller the scale.

14.On the map, it is generally up, north, down, south, left, west, right, east.

1. Asia is the largest continent in the world, and it is also the continent with the widest latitude and the longest east-west distance in the world.

2. Use the map to tell the latitude, sea and land location of Asia.

3. The topography of Asia is high in the middle and low in all directions, and the terrain is complex and diverse.

4. Characteristics of rivers in Asia: Originating in the central mountains and plateaus, they flow radially to the surrounding oceans, forming many long rivers.

5. The climatic characteristics of Asia: complex and diverse, with significant monsoon climate and wide distribution of continental climate.

6. The most widely distributed climate type in Asia is temperate continental climate.

7. Asia is vast and populous, with a population of about 100 million, and East Asia, Southeast Asia and South Asia are densely populated areas.

8. There are six Asian countries with a population of more than 100 million, including China, India, Indonesia, Pakistan, Bangladesh and Japan.

9. There are about 1,000 ethnic groups in Asia, and ethnic groups in different regions have created their own cultures.

10. The birthplace of the three major civilizations in Asia: the Yellow River-the middle and lower reaches of the Yangtze River, and the two river basins (Mesopotamian Plain).

11. The economic development of Asia is unbalanced, with Japan being a developed country and others being developing countries.

Compulsory knowledge points for geography in the first volume of the seventh grade:

1. The Earth and the Map.

The shape and size of the earth.

1) The Earth is an irregular sphere.

2) For the first time, a fleet led by the Portuguese navigator Magellan achieved a human circumnavigation around the earth.

3) The surface area of the earth is 100 million square kilometers, the maximum circumference is 40,000 kilometers, the equatorial radius is 6,378 kilometers, the polar radius is 6,357 kilometers, and the average radius is 6,371 kilometers.

2. Latitude and longitude.

1. The law of latitude change: from the equator (0° latitude) to the south and north poles. The maximum latitude is 90 degrees, at the South Pole, the North Pole.

2. The latitude north of the equator is called north latitude, which is represented by "n"; The latitude south of the equator is called southern latitude and is denoted by an "s".

3. With the equator as the boundary, the earth is divided into two hemispheres, north and south, with the north of the equator being the northern hemisphere and the south of the equator being the southern hemisphere.

4. The change law of longitude: from the prime meridian (0° meridian) to the west and east to 180°.

5. The longitude east of the prime meridian is called east longitude, which is represented by "e"; The longitude west of the prime meridian is called west longitude, which is denoted by "w".

6. The dividing line between the eastern and western hemispheres is: a meridian coil composed of 20°W and 160°E.

3. Land and sea.

1. The distribution of land and sea in the world is very uneven, the land is mainly concentrated in the northern hemisphere, but the North Pole is surrounded by an ocean (Arctic Ocean); The oceans are mainly concentrated in the north and south spheres, but around the South Pole is a land mass (Antarctica).

2. 71% of the earth's surface is ocean, and 29% is land.

3. The peninsula is the protruding part of the land that extends into the sea; A strait is a narrow waterway that connects two seas.

4. Seven continents: Asia, Africa, North America, South America, Antarctica, Europe, Oceania.

Four oceans: Pacific, Atlantic, Indian, Arctic.

5. Causes of sea and land changes: changes in the earth's crust and the rise and fall of sea levels are the main reasons for sea and land changes, and human activities will also cause changes in sea and land.

6. The German scientist Wegener proposed the hypothesis of continental drift.

In the 60s, earth science studies showed that continental drift was caused by plate movements.

The seven geographical knowledge points are summarized as follows:

1. Soil erosion.

Typical areas in China: Loess Plateau, low mountains and hilly areas in the south, the reasons for this:

1) Natural causes: concentrated precipitation in monsoon climate, heavy rainfall; surface vegetation is scarce; Loess soil loose Loess Plateau.

2) Anthropogenic causes: destruction of vegetation; unreasonable farming systems; Mining.

2. Desertification.

Typical regions in China: Northwest China (Xinjiang, Qinghai, Inner Mongolia, etc.), the reasons for this:

1) Natural causes: global warming, evaporation is vigorous; It is located in an inland area with little precipitation; Mice; Locust infestation.

2) human causes: overgrazing; excessive woodpicking; over-reclamation; irrational use of water resources; Improper protection of the construction of transportation lines and other projects.

3. Drought and water shortage.

Typical areas in China: North China, Northwest China, the middle and lower reaches of the Yangtze River, the cause of occurrence (North China):

1) Natural causes: temperate monsoon climate, low precipitation throughout the year, low river runoff; high variability of precipitation; Evaporation is strong in spring.

2) Human causes: densely populated, developed industry and agriculture, and large water demand; Water pollution is severe; There is a lot of waste and low utilization; Spring planting uses a lot of water.

4. Secondary salinization of soil.

Typical areas in China: Huanghuaihai Plain, Ningxia Plain, Hetao Plain, etc., causes:

1) Natural causes: frequent drought and flood climate (Huang-Huai-Hai Plain); low-lying terrain; Atmospheric precipitation is low, and irrigation water is the main source.

2) Human causes: unreasonable irrigation; Unreasonable water conservancy project construction (Weihe Plain).

5. Red tide. Typical areas in China: Pearl River Estuary, Hangzhou Bay, Bohai Sea, etc., the reasons for this:

1) Natural causes: high temperatures; still water; Quiet wind; The sea area is relatively closed.

2) Human causes: the coastal areas are densely populated and economically developed, and there are many industrial and domestic sewage discharged into the sea; A large number of chemical fertilizers and pesticides are used in the process of agricultural production; Due to the high degree of marine development and the expansion of the scale of aquaculture, the aquaculture waters have been seriously polluted.

The knowledge points of Geography 7th grade are as follows:1. Latitude: On the globe, follow the east-west direction, a circle around the globe.

2. The Earth's self-rotation around the Earth's axis is called the Earth's rotation.

3. Important characteristics of the earth's revolution: the orbital plane of the revolution is always at an angle between the earth's axis, and the north pole always points to the vicinity of the North Star.

4. The measurement of air temperature is measured with a thermometer placed in a louver box. The height at which the thermometer is placed is meters above the ground. Unit: (degrees Celsius). The average daily temperature is generally taken as the average of the four moments of 8 o'clock, 14 o'clock, 20 o'clock and 2 o'clock.

5. The boundary between China's monsoon area and non-monsoon area is Daxinganling-Yinshan-Helan Mountain, the most typical feature of monsoon climate is that rain and heat are at the same time, which is very conducive to agricultural production, but the disasters are also more serious, such as the abnormal summer monsoon brings flood and drought disasters, and the winter monsoon brings cold waves and freezing rain.