The topography and climate of China.

Main features of the terrain: 1. The terrain is diverse. On the vast land of China, there are majestic plateaus, rolling mountains, vast plains, low hills and large and small basins surrounded by mountains and low in the middle. There are five basic land types in China, which provide various conditions for the development of industry and agriculture in China. Various landforms provide favorable conditions for the all-round development of agricultural production in China, and also provide a certain foundation for the development of industrial production. 2. The mountains are vast. Usually people call mountains, hills and rugged plateaus mountains. China's mountainous area accounts for 2/3 of the country's total area, which is another remarkable feature of China's topography. The vast mountainous areas bring certain difficulties to the development of transportation and agriculture. Mountain areas can provide forest products, minerals, hydropower and tourism resources, which provides resource guarantee for changing the face of mountain areas and developing mountain economy. 3. The terrain is high in the west and low in the east, which is the general trend of surface fluctuation. China's topography is high in the west and low in the east, with a ladder-like distribution as a whole. The first step of the terrain is the Qinghai-Tibet Plateau, with an average elevation of more than 4,500 meters. There are Kunlun Mountain, Qilian Mountain and Hengduan Mountain in the northern and eastern edges, which are the dividing lines between the first and second steps of the terrain. There are large basins and plateaus on the second terrace, with an average elevation of 1000-2000m. Daxinganling, Taihang Mountain, Wushan Mountain and Xuefeng Mountain in the east are the dividing lines of the second and third steps of the terrain. The third step of the terrain is a vast plain, with hills and low mountains in the middle, most of which are below 500 meters above sea level. If you draw a topographic profile of China from west to east through the 32 N line, it is obvious that the western plateau, the central basin and the eastern plain are high in the west and low in the east. Even in the north or south, the natural environment is very different. Climatic characteristics: 1. The climate is complex and diverse. China has a vast territory, a wide latitude and a great distance from the sea. In addition, the terrain is different, the terrain types and mountains are diverse, so the combination of temperature and precipitation is also diverse, forming a diverse climate. 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 and 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. For example, 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 now it is 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 requirements in China are located at latitudes much higher than those in other countries with the same latitude in the world. For example, Huma County, Heilongjiang Province can grow rice, with a latitude of 52. 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. For example, the climate in the middle and lower reaches of the Yangtze River in China is warm and humid, and it is rich in products, belonging 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.