Common Special Phenomena in Geography of College Entrance Examination

There are some special natural phenomena in high school geography, which are quite common in the college entrance examinatio

Common Special Phenomena in Geography of College Entrance Examination

There are some special natural phenomena in high school geography, which are quite common in the college entrance examination and sometimes observed. In order to help students master the common special phenomena in geography, I bring you the following. Do you know why?

Geographical special phenomenon of college entrance examination (climate) 1 There is no sunny day in Guizhou.

There are more than 200 cloudy days a year in Guizhou, which is one of the regions with the most rainy days and the wettest climate in China. In most parts of Guizhou, the annual rainy days are above 150 days, and the average annual rainy days in Guiyang are 188 days. Among them, the rainy days in May averaged as many as 20 days, with the least in 65438+February, but there were still as many as 13 days.

Cause and course of action:

Guizhou is located in the southwest of China, far away from the winter wind source. The winter wind blows south and is weakened by the east-west mountains. When it reached the Yunnan-Guizhou Plateau, the airflow moved slowly and merged with the warm air that had stayed in Guizhou. The two sides were evenly matched, so they stayed here for a long time, which led to rainy weather.

(2) In spring, the warm air in the south is gradually strengthened, and the cold air in the north is quite active. Cold and warm air conflict with each other, so the weather in Guizhou is sunny, cloudy and rainy, and the weather is changeable.

(3) In summer, the cold air in the north moves northward, and the warm and humid air from the southern ocean is active in the Guizhou Plateau. The altitude of Guizhou Plateau is above 1000 meters, and the ground fluctuates, and the warm and humid air is disturbed by topographic uplift, forming clouds and rain. Sometimes cold air from Sichuan meets warm and humid air from the south, which is more likely to form rainy weather or produce strong thunderstorms.

(4) In autumn, the cold air in the north begins to go south, and the warm air cannot retreat. Constant confrontation between cold and warm air often leads to rainy weather.

In a word, the rugged ground in Guizhou Plateau has many opportunities for air uplift, disturbance, blockage, friction and contact with cold and warm air, which is the main reason for the continuous rain in Guizhou.

2 Go to Taipei to see the rain phenomenon in winter: Taipei has abundant rainfall and frequent precipitation in winter.

Reason:

Taiwan Province Island is located in the southeast of China, surrounded by the sea. In winter, the wind moves to the south, because the earth's rotation is biased, which causes the airflow to deflect and become a northeast wind. Because the airflow passes through the ocean, the originally dry airflow is full of water vapor.

(2) Taipei is low-lying, with mountains in Taiwan Province Province in the south. When the airflow reaches Taipei, it rises and condenses to form topographic precipitation.

(3) Winter winds have a long influence, so Taipei is rich all winter.

3 Spring rain in North China is as expensive as oil: In spring, farming begins to grow and germinate, that is, when crops need water most, the spring drought in North China is more serious. Spring rain accounts for 10- 15% of the annual precipitation, and in some places it is less than 10%. Therefore, "Spring rain in North China is as expensive as oil".

Reason: ① Spring receives two rainy seasons, autumn and winter.

(2) In spring, the temperature rises quickly, windy days and strong evaporation often lead to persistent drought.

(3) Although North China is in the monsoon region, the polar front lingers along the coast of South China from late April to early May, and the rainy season has not yet arrived.

⑤ The river flow in North China is not large, and it is mainly replenished by precipitation. In spring, agricultural water demand is large, but irrigation water is insufficient.

4 South China's spring rain sends spring home

Reason: From late April to early May, the polar front wandered along the coast of South China, bringing rainy weather to the south of Nanling.

In the middle and late May, the polar front jumps to Nanling and Jiangnan hills, and can spread to the middle and lower reaches of the Yangtze River, resulting in continuous rainfall in this area in spring.

The reason why it rains on Qingming Festival in Jiangnan is the same as above.

6 continuous autumn rain in southwest China

Phenomenon: It generally appears in September-165438+ 10, and the earliest appearance date can sometimes start in late August and end in late 10 at the latest. Mainly in Sichuan, Chongqing, Guizhou, Yunnan, eastern and southern Gansu, Guanzhong and southern Shaanxi, western Hunan and western Hubei. Especially in Sichuan basin, southwest Sichuan and western and northern Guizhou. The main feature is that there are many rainy days, but the rainfall is not large.

Reason: 1, southwest monsoon, and it only leaves China in September and 10. It is difficult to transport warm and humid air from the Indian Ocean to this area in autumn, which makes this area rich in water vapor conditions.

2. With the cold air moving eastward from the north side of the plateau or backward flowing from the east to the west of China, cold and warm air frequently meet in the west of China, forming the autumn rain in West China.

7 *** Sunshine City

* * * The annual average total sunshine hours is as high as 3,005.3 hours, with an average daily sunshine of 8 hours 15 minutes.

Reason: ① * * * is located in the Qinghai-Tibet Plateau, with high altitude, and can receive light earlier.

② High atmospheric transparency: the altitude is high, the atmosphere is thin, there are mountains in the north, and sandstorms in the northwest are difficult to reach, so the atmospheric transparency is high.

(3) Rainfall usually occurs at night: in the Yarlung Zangbo River basin, the temperature difference between the valley bottom and the mountain top is large, the temperature at the valley bottom is high at night, and the temperature at the mountain top is low, resulting in rainfall due to the sinking of airflow, with less clouds during the day.

8 Chongqing Wudu

The annual average foggy days in Chongqing are 104 days, which is more than that in London, so it is called the foggy city.

Reason:

1, Chongqing is located at the intersection of the Yangtze River and Jialing River, with rich water vapor sources and a relative temperature of 80%.

2. Chongqing is located in the southeast edge of Sichuan Basin, surrounded by high mountains, with rugged ground, extremely low wind speed and weak wind power.

3, the ground temperature is quite high during the day, and evaporation is constantly strengthened, so that the air contains a lot of water vapor; At night, especially on sunny nights in autumn and winter, the radiation cooling of the ground is very obvious, and the cold air in the mountainous area on the edge of the basin will sink along the hillside, which will make the air near the ground cool down very sharply, and eventually lead to the continuous reduction of the air's ability to contain water vapor, and the excess water vapor will condense and form fog.

9 Spring City Kunming

Kunming is mild in winter, and the coldest average temperature is about 7.8℃. The average temperature in the hottest summer is around 20℃, and the highest temperature is not higher than 32℃. It is warm in winter and cool in summer, and Kunming is called "Spring City".

Reason:

① Latitude: 24 ~ 26 N, subtropical monsoon climate.

② It is far away from the source of winter wind, blocked by mountains, and less affected by winter wind.

③ The high in the west and low in the south are easily affected by the warm and humid air flow in the Indian Ocean.

④ Located in the south of Kunming quasi-static front, in the control area of warm and dry airflow.

⑤ Regulating function of Dianchi Lake

10 Turpan, Huozhou

Phenomenon: It is hot in summer, so it is called "Fire State". The average temperature in June, July and August is above 30~C, and the absolute maximum temperature can reach 47.8℃, which is the highest temperature record in China.

cause

1, geographical location: 42 degrees 56 minutes north latitude, located in the northwest inland of China.

2. Climate: temperate continental climate, with long sunshine time in summer and hot and dry summer.

3. Terrain: The terrain is low, surrounded by mountains, and the heat is not easy to dissipate.

4. Physical properties: the surface is sandy, with low specific heat and rapid temperature rise.

5. Vegetation conditions: the vegetation on the surface is scarce, the ground is * * *, and the sunlight is direct, so the plant regulation function is weak.

1 1 Yu Ji is on fire

Phenomenon: The annual average rainfall is five or six thousand millimeters, which not only far exceeds the annual average rainfall of 2500 millimeters in Taiwan Province Province, but also is the highest in East Asia.

Reason:

1. Double influence of northeast wind and topography in winter: From September to March of the following year, the northeast wind on the east side of Mongolian Siberian high passes through the East China Sea of Taiwan Province Province, bringing a large amount of warm and humid airflow, which is blocked by mountains in Taiwan Province Province and forms abundant topographic precipitation.

2. Summer is influenced by both the southeast monsoon and the terrain: the warm and humid southeast monsoon is blocked by the mountains in Taiwan Province Province, and the terrain is rich in precipitation.

3. Typhoons in summer and autumn can bring a lot of precipitation.

4, the Japanese warm current, the warm current has the effect of warming and humidifying, and it will also form precipitation.

12 Rain Harbor "Keelung"

It rains more than 200 days in 365 days a year, so it is also called Rain Harbor. According to the statistics of meteorological data, the average annual rainy days in Keelung are 2 13.6 days, ranking first in the towns of Pingdi. Judging from the average annual rainfall, the average annual rainfall in Keelung is as high as 2903mm, ranking first in Taiwan Province Province.

Reason: It rains in winter for the same reason as it rains in Taipei in winter.

Plum rain in spring and summer,

Rain brought by typhoon or northwest rain in summer.

Geographical special phenomenon of college entrance examination (hydrology) 1 ice flood: river flood phenomenon caused by ice jam, thawing or melting of ice and snow. The ice flood of the Yellow River occurs in the reach of the Yellow River. Main reach: 1, Zhongwei to Shizuishan, Ningxia, 2. Zhengzhou, Henan to Binzhou, Shandong. Reason: 1, the river must have an ice age, 2. The river must flow from low latitude to high latitude. .

2 Jingjiang Oxbow Lake

1 Definition: The curved channel is cut and straightened due to excessive bending, and the original channel is abandoned.

2 formation process:

1. When the river bed gradient decreases, the downward erosion of the river is weakened and the lateral erosion is enhanced. The flowing water constantly scours the river bank, forming convex banks and concave banks. When the river reaches the bend, due to inertia and centrifugal force, the water flows to the concave bank, which is strongly eroded and forms a deep ditch. At the same time, the compensation water flows to the convex bank at the bottom of the river, the bottom water pressure is pushed to the convex bank, and the substances washed down from the concave bank are brought to the convex bank, which is accumulated to form a beach due to the slow flow speed of the convex bank. These two flows are in opposite directions, forming a transverse circulation on the cross section of the river. Under the action of transverse circulation, the river becomes more and more curved, forming a meandering flow. On the plain with deep and loose sediments, many free meanders are formed, which can swing freely.

2. Rivers are constantly scouring and eroding banks, and meanders are constantly developing.

3. The meander becomes more and more curved.

4. The river scours and erodes the most curved bank, so the river is cut and straightened.

5. The river flows away from the straight part, and the original meander is abandoned.

6. The original abandoned meander turned into an oxbow lake.

3 Jingjiang Oxbow Lake Analysis:

Jingjiang is another name for the Yangtze River from Zhicheng, Hubei Province, China to Chenglingji, Hunan Province. There are upper Jingjiang River and lower Jingjiang River. Upper Jingjiang Zhicheng-Ouchikou, the river channel is relatively stable; Chenglingji, the winding mouth of Ouchi, the lower Jingjiang River, is known as the "nine-bend ileum".

1 Natural environment: The Yangtze River runs down from the Three Gorges, crosses mountains and passes through the Jingmen estuary. The terrain is steep, plunging thousands of miles, the flow velocity is slow, and the beach cutting effect of running water is weakened, which is suitable for meandering development. At the same time, it brings a lot of alluvial sediment, and the soil structure of Jingjiang section is stuck with sand, which is easy to collapse and aggravate the meandering development.

There is a part of artificial flood diversion area in Shangjingjiang section, which makes flood and sediment flow into Dongting Lake from Yangtze River mainly through Shangjingjiang estuary. Therefore, the annual and inter-annual discharge of the lower Jingjiang River changes little, the water flow is gentle and stable, and the beach cutting effect of the water flow is reduced, which is conducive to the development of meandering.

3 Yangtze River South-to-North Water Transfer Project: a major strategic project to alleviate the serious shortage of water resources in northern China. The South-to-North Water Diversion Project is divided into three water diversion routes: the eastern route, the middle route and the western route, which greatly relieves the serious shortage of water resources in northern China and promotes the coordinated development of economy, society, population, resources and environment in the north and south. The west line project is located in the highest Qinghai-Tibet Plateau, which can control the whole northwest and north China. Due to the limited water supply in the upper reaches of the Yangtze River, water can only be replenished to the northwest and parts of North China in the middle and upper reaches of the Yellow River. The middle route project passes through the west side of the third step and takes water from the middle reaches of the Yangtze River and its tributary Hanjiang River, which can supply water to most areas of the Huang-Huai-Hai Plain by itself. The eastern route project is located on the east side of the third step, and it needs to pump water to the north because of its low terrain.

4 Yellow River Hetao area:

5 Zoige peat swamp:

The formation of peat swamp requires three conditions: climate, geography and structure. The climate should be suitable for plant growth, there should be water bodies in geography, and the tectonic swamp should continue to slowly settle.

The dead leaves of plants growing in swamps must be submerged in water and isolated from the air to prevent oxidative decomposition, biochemical reactions under reduction conditions and peat substances such as humic acid. If there is no water swamp condition, plant debris will decompose and cannot be turned into peat. Peat can't form like the northeast forest.

Structural factors: the accumulation of plant residues in water will make the water shallow sooner or later, and finally the plant residues will be exposed to the air for weathering and cannot become peat. Therefore, peat bogs have been continuously precipitated for a long time. When the settling speed is the same as the accumulation speed of plant residues, the peat layer becomes thicker and thicker. When the settling speed of swamp is faster than the accumulation speed of plant residues, plants will be submerged by water and peatization will end. When the deposition rate of swamp basement is less than the accumulation rate of plant residues, the plant residues decompose and the peat process stops. Therefore, when climate and environmental changes have little influence, when the accumulation speed of plant residues is the same as the settlement speed of swamp foundation, the accumulation thickness of peat layer is mainly controlled by the length of time.

6 potential swamps in Sanjiang plain

The swamps in Sanjiang Plain are mostly developed in the low-lying areas near the mountains and the low-lying floodplains on the plains.

Terrain: The terrain here is low and flat, the slope is extremely slow, and the water collection conditions are good. There are more than 20 major rivers in the plain, most of which have narrow riverbeds and curved channels, and even swamp rivers with no obvious channels have poor drainage.

Climate: Winter is cold and long, summer is wet and cool, rainfall is concentrated, water is abundant, evaporation is small, it can't be discharged, and autumn waterlogging is serious.

Soil: Surface water began to freeze at the end of 10 or the beginning of 1 10, forming a frozen layer. Heavy snowfall in winter, with a thickness of 40 cm and a maximum thickness of 68 cm. Ice and snow melt in spring, but because there are clay layer, loam layer and underground frozen layer below, water is not easy to penetrate, thus aggravating surface water accumulation.

Biology: In the cold, humid and watery environment, marsh plants such as Carex, Cinnamomum camphora and weeping willows flourish, with a coverage rate of over 70%. The interaction of water, soil and grass leads to swamps all over here, concentrated and contiguous.

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