The geography and climate of China.

1. The climate is complex and diverse.

China has a vast territory, a wide latitude, a long distance from the sea, and different terrain types and mountains, so there are various combinations of temperature and precipitation, forming a variety of climates. In terms of climate types, the east belongs to monsoon climate (which can be divided into subtropical monsoon climate, temperate monsoon climate and tropical monsoon climate), the northwest belongs to temperate continental climate, and the Qinghai-Tibet Plateau belongs to alpine climate. According to the temperature zone, there are tropical zone, subtropical zone, warm temperate zone, middle temperate zone, cold temperate zone and Qinghai-Tibet Plateau. Divided from dry and wet areas, there are humid areas, semi-humid areas, semi-arid areas and arid areas. In addition, the same temperature zone can contain different dry zones and wet zones; There are different temperature zones in the same dry and wet area. Therefore, under the same climate type, there will also be differences in heat and humidity. The complexity and diversity of terrain also make the climate more complex and diverse.

2. Monsoon climate is remarkable.

China's climate is characterized by high temperature and rainy summer, cold and little rain in winter, and the high temperature period is consistent with the rainy period. Because China is located in the east of Eurasia, the largest continent in the world, on the west coast of the Pacific Ocean, and near the Indian Ocean in the southwest, the climate is greatly influenced by the mainland and the ocean. In winter, the north wind blows from the mainland to the ocean, and in summer, the south wind blows from the ocean to the land. Winter winds are produced in the interior of Asia, which is cold and dry. Under its influence, there is little precipitation and low temperature in most parts of China in winter, especially in the north. The summer monsoon comes from the Pacific Ocean in the southeast and the Indian Ocean in the southwest, and it is warm and humid. Under its influence, precipitation generally increases, and rain and heat are in the same season. China is widely influenced by the alternation of winter and summer monsoon, which is the most remarkable and typical region in the world. Compared with other parts of the world at the same latitude, the temperature in China is low in winter and high in summer, with a large annual variation, and precipitation is concentrated in summer, which is the characteristic of continental climate. Therefore, the monsoon climate in China is continental, which is also called continental monsoon climate.

Advantages of Climatic Conditions The complicated and diverse climate makes most crops, animals and plants in the world find suitable places to grow in China, which makes China rich in crops, animals and plants resources.

Corn, whose hometown is in Mexico, is widely planted in China and has become one of the important food crops in China. Sweet potato was first introduced in Zhejiang and widely planted in China.

The remarkable characteristics of monsoon climate in China also provide favorable conditions for agricultural production in China. Due to the high temperature and superior heat conditions in summer, many crops with high heat conditions in China are located at latitudes far higher than those in other countries with the same latitude in the world. Rice can be planted in Huma County, Heilongjiang Province, which is 52 north latitude. It is rainy in summer, and the high temperature period is consistent with the rainy period, which is beneficial to the growth and development of crops. The middle and lower reaches of the Yangtze River in China have a warm and humid climate and rich products, which belong to subtropical monsoon climate, while North Africa and Arabian Peninsula at the same latitude are mostly arid and semi-arid desert landscapes.

Although the climate in China is beneficial to the development of agricultural production in many ways, it also has disadvantages. Frequent disastrous weather in China often has adverse effects on China's production, construction and people's lives. Among them, drought, flood, cold wave and typhoon are the main disastrous weather that have great influence on China.

Drought and flood disasters occur once a year on average in China, mostly in the north and also in the south.

In summer and autumn, the southeast coast of China is often hit by tropical storms-typhoons. Typhoons (called typhoons when tropical storms develop to a particularly strong degree) are the most frequent from June to September.

In autumn and winter in China, cold air from Mongolia and Siberia keeps going south. When the cold air is particularly strong, the temperature drops suddenly and a cold wave appears. Cold wave will cause low temperature, strong wind, sandstorm, frost and other disasters. 1. Winter temperature distribution

It can be seen from the isotherm map of 5438+ 10 in June that the 0℃ isotherm passes through the southeast edge of Huaihe-Qinling-Qinghai-Tibet Plateau, and the temperature in the north of this line (including the north, northwest inland and Qinghai-Tibet Plateau) is below 0℃, and the temperature in Mohe, Heilongjiang Province is below -30℃. The temperature in the south of this line is above 0℃, and the temperature in Sanya, Hainan is above 20℃. Therefore, it is warm in the south and cold in the north, and the temperature difference between the north and the south is large, which is the distribution characteristics of winter temperature in China.

The main reasons for this feature are: the influence of latitude position, direct sunlight in the southern hemisphere in winter, and most parts of China are in the northern temperate zone, so solar radiation gets less heat. At the same time, the latitude difference between north and south is 50℃, and the height difference between north and south is significant, which leads to the low temperature in most parts of the north and the large temperature difference between north and south.

The influence of winter winds In winter, cold and dry winter winds often blow from Mongolia and Siberia, and the northern region bears the brunt, thus aggravating the cold in the north and increasing the temperature difference between the north and the south.

2. Summer temperature distribution

From the isotherm map of China in summer in July, it can be seen that except for the Qinghai-Tibet Plateau and Tianshan Mountain, most areas are above 20℃, and many places in the south are above 28℃; The Turpan Basin in Xinjiang has an average temperature of 32℃ in July, which is the hottest center in China in summer. Therefore, except for the Qinghai-Tibet Plateau and other high-lying areas, the temperature in China is generally high, and there is little difference between the north and the south, which is the characteristic of summer temperature distribution in China.

The reasons are as follows: In summer, the direct sunlight is in the northern hemisphere, and the amount of sunlight and heat obtained in all parts of China generally increases. In addition, due to the high latitude and long days in the north, the light and heat gained are relatively increased, which shortens the temperature difference with the south, so the temperature in China, China is generally higher.

3. China's temperature zone

In China, accumulated temperature is used to divide temperature zones. Most crops can grow actively only when the daily average temperature rises above 10℃, so the days when the daily average temperature is continuously ≥ 10℃ are usually called the growth period. The total temperature accumulated by the daily average temperature during the growth period is called accumulated temperature. The accumulated temperature of an area reflects the heat status of the area. According to the distribution of accumulated temperature, China has divided five temperature zones and a special Qinghai-Tibet Plateau. The heat in different temperature zones is different, the growth period is different, and the farming system and crop species are obviously different.

Farming temperature zone ≥ 10℃ The main crops are tropical >: 8000℃ 365 Hainan Province and subtropical areas such as rice, sugarcane and natural rubber in southern Yunnan, Guangdong and Taiwan Province Province 4500℃-8000℃ 2 18-365 Qinling-. Warm temperate regions such as rape are 3400℃- most of the middle and lower reaches of the Yellow River and middle temperate regions such as winter wheat, corn, cotton and peanuts1600℃-3400℃100-171Northeast China, Inner Mongolia and northern Xinjiang are mostly spring wheat, corn, flax. 100 Qinghai-Tibet Plateau, such as spring wheat and potatoes harvested once a year in northern Heilongjiang Province and northeastern Inner Mongolia: 800 precipitation > Evaporation The semi-humid agricultural areas mainly consisting of paddy fields are from Qinling to the south of Huaihe River, southern Qinghai-Tibet Plateau, northeastern Inner Mongolia and eastern Northeast China > 400 precipitation > Evaporation The semi-arid agricultural areas mainly consisting of forest grassland and dry land in the northeast plain, north China plain, most of Loess Plateau and southeastern Qinghai-Tibet Plateau < 400 precipitation.