Summary of geography review knowledge points for senior high school entrance examination

Generally, sand dunes in nature are hills or ridges piled up by wind, which are common in coastal areas, some river valleys and some dry sand surfaces in dry seasons. The following are the knowledge points of geography review in the senior high school entrance examination, I hope it will help you!

Review knowledge points of geography in senior high school entrance examination dune

The types of sand dunes can be divided according to the structure, wind direction and sediment concentration of sand-laden airflow, and also according to the relationship between the direction of wind action and the morphological distribution of sand dunes.

There are three main types of sand dunes: ① crescent-shaped sand dunes, also known as transverse sand dunes. The plane is like a crescent moon, and the direction is perpendicular to the wind direction or greater than 60? . There are two sharp corners on both sides of the sand dune, which extend forward with the wind, and the height is generally from several meters to more than ten meters. The windward slope is gentle, with a slope of about 5? ~20? ; Leeward slope is concave and steep, with a slope of about 28? ~34? . Its formation process can be divided into: cake dune stage, shield dune stage, embryo crescent dune stage and crescent dune formation stage. Wind-blown sand flows through sand piles to produce different wind speed changes and pressure distribution characteristics. The top of the sand pile has high wind speed and low air pressure, and the leeward slope has low wind speed and high air pressure. The leeward slope of the sand pile forms a vortex, which accumulates sand on both sides of the leeward slope of the sand pile and forms a horseshoe-shaped depression between the two sharp corners of the leeward slope. The depression continued to expand, forming the embryonic crescent dunes. With the continuous accumulation, sand dunes increase, and the sand on the leeward slope slides down due to gravity, and the vortex blows to both sides and develops into wings, forming a typical crescent-shaped sand dune. Crescent dunes are interconnected to form crescent dunes chain, compound crescent dunes and compound dunes chain. Parabolic dunes can be formed when the ground of transverse dunes is blocked by plants and shrubs, and the plane shape is just the opposite of crescent. Continue to develop and form parallel and low double sand ridges.

② Longitudinal sand ridges. The trend of sand dunes is basically the same as that of wind-blown sand (generally less than 30? )。 Strip distribution, tens of kilometers long, about tens of meters high and hundreds of meters wide. When the sand source is sufficient, a composite longitudinal sand ridge is formed.

(3) Pyramid dunes, honeycomb dunes, etc. It can be formed in front of the mountain or in areas with complex terrain under the action of long-term multi-directional wind and sand flows.

Summary: Sand ridges extend for a long distance, sometimes for several kilometers. Dunes are mainly crescent-shaped and long. In some places, there is a star-shaped or pyramid-shaped sand dune, which is polygonal in plan. People think that this kind of sand dune is immobile, so it becomes a signpost for desert travelers.

Geography review guide for senior high school entrance examination: frontal weather

① The gradient of warm front is relatively small, about1150. The typical cloud systems are cirrus, cirrostratus and stratus, and the near-surface front is nimbostratus. The precipitation starts from the stratus, mostly continuous. If warm air is unstable, convective weather such as cumulonimbus clouds will also appear on the warm front. Warm fronts are rare in China.

② The slope of the first cold front is about1100, and its weather is similar to that of the warm front, but the sequence of cloud and rain is opposite to that of the warm front. In East Asia, this cold front generally moves from northwest to southeast, which is one of the important weather systems that affect the weather in China. In winter, the cold front is generally strong, with a large influence range, and sometimes it can reach the South China Sea; In summer, the cold front is weak, and the influence range is small, generally only reaching the Yellow River basin.

③ The slope of the second cold front is relatively large, about 65,438+0/70, and the surface layer is sometimes almost vertical or inclined forward. The front of the ground front is mostly convective weather, sometimes accompanied by squall line, which can produce hail, tornado and other disastrous weather. The frontal cloud system is influenced by many factors, especially the topography, so in mountainous China, the frontal cloud system is often far from the typical characteristics. The second kind of cold front is relatively rare in China, which appears in the Yangtze River basin in spring and the Yellow River basin in autumn.

④ The weather of the stationary front is similar to that of the first cold front, except that it has a wide range of clouds and rains, which are mostly found in Nanling area of South China and Yunnan-Guizhou Plateau. Because the cold front is blocked by the terrain after going south, it is in a quasi-static state and can stay for ten days or half a month, resulting in rainy weather. ⑤ Blocking front has both cold and warm weather characteristics. Typical occlusion fronts are rare in China, but in northwest, north and east China, terrain occlusion fronts often appear in winter.

Summary: if the air is dry, the front and the dense equipotential temperature surface are almost parallel; If the air is humid, it is almost parallel to the dense equilibrium surface. All these characteristics of the front area show that the front area is the concentration area of atmospheric baroclinic and the storage area of atmospheric potential energy.

Key points of geography review for senior high school entrance examination: cold front crossing the border

A cold front is what people often call a cold air front. It is Depth Charge with cold air heading south, and it is the most common weather system that affects China, especially in winter.

Before the cold front crosses the border: the temperature is high, the weather is clear and the air pressure is low, which is controlled by a single heating substance.

When crossing the border: strong wind, cooling, rainy (precipitation is concentrated behind the front, but also before the front)

After the cold front:

1, temperature: drop

2. Air pressure: decrease first and then increase.

3. Precipitation: There is rain behind the front.

4. Weather: It will clear up.

Summary: When the front is moving, if the warm air mass plays a leading role and pushes the front to move to the cold air side, this front is called a warm front. In China, the warm front often appears on the east side of cyclone center, and it often appears in pairs with the cold front. Generally, when a warm front passes through the boundary, the air pressure decreases and the temperature increases.

Geography review guide for senior high school entrance examination: Western Europe

1, location and scope:

Western Europe refers to the western half of Europe, bordering the Atlantic Ocean in the west, the Arctic Ocean in the north and the Mediterranean Sea in the south; It covers an area of 5 million square kilometers.

2. Strong economic strength:

(1) Most western European countries are economically developed countries. Such as Britain, France and Germany.

(2) The economic development level of European countries ranks first among all continents.

(3) Switzerland? Watch kingdom? ; Denmark? European Ranch and Food Bank? ; Swedish manufacturing industry is famous; Norway's per capita aquatic product output ranks first in the world; The Dutch flower planting industry is developed, and the famous ones are? Tulips? .

3. Prosperous tourism:

(1) Three famous tourist countries in Western Europe: France, Spain and Italy.

(2) Rich tourism resources:

Vienna (Austria), the city of music;

② Eiffel Tower, Louvre and Arc de Triomphe in Paris, France;

3 lakes and mountains? Watch kingdom? Switzerland;

(4) Roman monuments, Venice, the Italian water city;

⑤ Sunny beaches along the Mediterranean coast, watching bullfighting in Spain;

⑥ Watch the flower windmill and visit the Dutch reclamation project;

⑦ Take a boat trip to the fjord and watch the midnight sun in Norway;

The Colosseum, an ancient capital of 8,000 years;

Beer in Munich, Germany.