Temporal and Spatial Distribution of Precipitation in China

In space, it is simply "more in the south and less in the north, less in the east and more in the west".

Specifically described as:

The basic trend of spatial distribution of precipitation in China is decreasing from the southeast coast to the northwest inland, and the more inland it is, the faster it decreases. If the 400 mm isorainfall line is taken as the boundary, China will be divided into two parts, the humid part controlled by the East Asian monsoon in the east and the arid part of Central Asia in the west, which is similar to the boundary between the domestic inflow area and outflow area, and this boundary is also of great significance to the natural phenomena in China and the production and development of agriculture, forestry and animal husbandry.

In the humid part, the isorainfall line runs northeast-southwest and the precipitation decreases with latitude. The southern part of China is the most active area of hydrological cycle, and the 800 mm isorainfall line is roughly consistent with the Qinling-Huaihe line. The precipitation on both sides of the Yangtze River is between 1 0,000-1 200 mm, and most of the hills in the south of the Yangtze River and Nanling Mountains exceed10,400 m, and most of the coastal hills in Guangdong, Taiwan Province and Hainan Island can reach more than 2000 mm. The Beibu Gulf is deeply affected by typhoons, and the annual precipitation is particularly high, exceeding 2000 mm. In western Yunnan and eastern Tibet. Relatively small rainy areas are formed, with annual precipitation exceeding 65,438 0.400 mm. Among the above rainy areas, relatively few rainy areas are formed in Kunming, north of Guiyang and Sichuan Basin, with annual precipitation generally between 800-L ~1000 mm, and north of Qinling-Huaihe River, most areas are not very active in water circulation and the climate is not very humid. The Huaihe River Basin and most of the Qinling Mountains are between 800- 1000 mm, the lower reaches of the Yellow River and the North China Plain are 500-750 mm, and the Northeast Plain has dropped to 400-600 mm, but the Changbai Mountain area exceeds 800 mm, and the Yalu River Basin can reach 1.200.

In arid areas, the annual precipitation in the western Daxinganling Mountains, Inner Mongolia Plateau and Loess Plateau is generally 200-400 mm ... Tianshan Mountain and Altai Mountain in northwest Xinjiang are affected by the Atlantic-Arctic water vapor system, which can reach 400-600 mm at most. The remaining annual precipitation is below 200 mm, which decreases rapidly to the most arid central areas in China, such as southern Xinjiang, western Gansu and northwestern Qaidam Basin. The annual rainfall in these arid central areas is almost below 50 mm, especially in the Tarim Basin, which is less than 20 mm, and the average annual rainfall at the end is only 9.2 mm, and it doesn't even rain in some years, which is the place with the least annual rainfall in China. Due to the blocking of the surrounding mountains, it is difficult for the humid Indian Ocean water vapor to penetrate into the northern Tibet Plateau, which is also a region with less rainfall in China, and the annual precipitation is estimated to be below100 mm.

China has a vast mountainous area, and mountainous terrain has a significant impact on precipitation distribution. In a certain range, the precipitation in mountainous areas is more than that in plains and basins, and the windward area in the same mountainous area is more than the leeward area, so there are many closed rainy centers or less rainy centers on the precipitation distribution map in China. The central mountain range of Taiwan Province Island faces tropical air mass, equatorial air mass and marine metamorphic polar air mass from north to south, east, north and south, and is deeply affected by typhoon. The annual precipitation on the windward slope of the mountain is more than 3,000 mm, with the most in Huoshaoliao, with an average annual precipitation of 6,489 mm from 65,438 to 65,438 to 0945 and a maximum of 8,489 mm a year. However, the leeward Taiwan Province Strait, influenced by the mountains of Taiwan Province Province, has less than 1000 mm, while the Penghu Islands only have 800 mm. The southeast slope of Wuzhishan Mountain in Hainan Island is influenced by tropical ocean air mass and equatorial air mass all the year round. The annual rainfall is over 2000 mm, and the leeward west coast is only about 1000 mm, forming a tropical savanna landscape. The annual rainfall on the windward slopes of Nanling Mountain and Wuyishan Mountain in southern Fujian and Zhejiang can reach more than 2,000 mm, which is about 500 mm more than the coastal zone and coastal islands from Hangzhou Bay to Leizhou Peninsula, while the two lake basins in the leeward zone are only about 1500 mm ... Emei Mountain in the west of Sichuan Basin, where the southeast airflow rises due to topography, the annual rainfall is more than 1400 mm, and the maximum year is (August/kloc-. The Qinling Mountains are far away from the sea and located to the north than the Huaihe River Basin, but the precipitation is similar, which is obviously the result of the influence of tall mountains. In North China, Shandong hilly area is rich in precipitation, with the average annual rainfall exceeding 700-800 mm. The windward slopes of Taihang Mountain and Yanshan Mountain are also 600-700 mm. During this period, the precipitation in North China Plain is only about 500 mm, and the situation in Northeast China is similar to that in North China. The eastern Changbai Mountain has the most rainfall, followed by the windward area of Daxing 'anling, and most of the precipitation in the plain is below 500 mm Due to the influence of southwest airflow, the precipitation on the western slope of the mountain and deep valley parallel to the longitudinal valley in western Yunnan is richer than that on the eastern slope, which is contrary to the area affected by southeast airflow. At the same time, mountains and narrow valleys alternate here. Most of the peaks are above 3000 meters, and the bottom of the narrow valley is about 1000 meters above sea level. Because it is difficult for hot and humid air to flow northward through the narrow valley, a very dry and hot valley is formed. For example, the annual precipitation in Longling on the western slope of Gaoligong Mountain is as high as 2654.38+0.60mm, while the annual precipitation in Baoshan on Dongpo is only 958mm, and the nearby Nujiang River Valley is less than 750 mm. In the Hengduan Mountain area in the southeast corner of Tibet, warm and humid air flows from the Indian Ocean and the Bay of Bengal can reach the east of Nyainqentanglha Mountain along the spacious valley, and the annual precipitation in the area south of Bomi is higher than 1000mm, which can exceed 4,000mm at most. However, in the north of the Himalayas, south of the Yarlung Zangbo River and west of Guandong Mountain, it is a famous "rain shadow belt at the northern foot of the Himalayas" with an annual precipitation of less than 300 mm. The distribution of precipitation in Xinjiang is strictly controlled by topography. There are three rainy centers (Altai Mountain, Tianshan Mountain and the northern foot of Kunlun Mountain) and three less rainy centers (Junggar Basin, Tarim Basin and Turpan Basin) in the whole region. The annual precipitation of Chaka in the east of Qaidam Basin is about 200 mm, which decreases sharply to the west, with Golmud less than 30 mm and Qilian Mountain nearby with 300-500 mm..