Average annual rainfall

Calculation method

The sum of the precipitation in one month or one year, called a month or annual precipitation.

The amount of precipitation is to fall from the sky to the ground to the ground, after the depth of accumulating on the horizontal plane without evaporation, penetration, and loss. It is usually measured by rainfall, and twice is observed each day (8 points and 20 points). In millimeter (mm).

According to the moon, annual precipitation in the month, the annual precipitation can be obtained, called the average precipitation of the month or the year, and the two precipitation feature values ​​can reflect the area precipitation in the region. Basic conditions.

Measurement method

Determination of instruments for precipitation, two types of rainchers and rain meters.

Sub-sensor and recorder two parts, there is a cable connection. The inductor is measured with a bucket measurement, and the precipitation data is read from the cumulative counter and self-clock.

In the absence of rainfall, we can also determine the precipitation intensity from the time of rainfall:

light rain: raindrops are clearly resolved; the ground is full of wet, but no volume Water or water is formed very slow.

Nurse: Rain drops continue to wire, raindrops splash, smear rain; ground water formation is faster.

Restorine

The rainfield is used to measure the accumulated precipitation in a period of time. The outer casing is a metal cylinder, the upper section is a water funnel having a diameter of 20 cm, in order to prevent rainwater splashes, the retention area and shape, the cartridge is formed into an inner straight outer blade shape A water cylinder is placed in the lower tube to collect rainwater. When measuring, the rain poured into a special rainfall cup reading precipitation millimeters. The water storage bottle is removed, and the snow without funnel is replaced, and the snow can be directly collected in the rainfall cartridge. After the snow is melted, then the snow scales can be overweight and then converted into millimeters according to the tubular area.

Rainometer

The rainbow rain gauge is an instrument that can continuously record precipitation and precipitation time. The shape and size of the upper flourishing funnel are the same as the rainfall. When the rain is introduced into the mesh, the float in the amount of the tube will rise up with the water level, and the self-billet is driven from the self-contained paper to the rising water level. When the water level in the measuring cylinder reaches 10 mm, the water is rapidly discharged by means of the siphon, and the pen tip returns to zero recording. Self-satisfaction bell gives the accumulation process over time.

The bucket rain meter is a wired telemetry instrument that can be continuously recorded with time variation and measurement of accumulated precipitation. Sub-sensor and recorder

two parts, there are cables. The inductor is measured with a dumpable triangular container, which can be rotated about the horizontal axis with a horizontal axis, so that the two side containers are flowing water, and when the container is filled with a certain amount of rain (0.1 or 0.2 mm), flipped out of the center of gravity, pour the water out, as the rain continues, will turn around the flipping, the contact switch turns the number of tuning flips into electrical signals, read the cumulative counter and self-reading Precipitation information.

World's mostWorld Wet poles

Huaiji Ale (Hawaii, USA) has an average of 335 days average annual rain, annual average rainfall 12244 mm

World dry pole

Atacama desert, located near South America, South Return line, known as the world "dry pole", an average annual precipitation is less than 0.1 mm In 1845-1936, the drops did not fall.

World Water

乞 朋 齐 is a mountain village in the Northeast of India, but it is known as one of the most rainfall in the world. World. In 1861, the annual rainfall is 22,990 mm. Since the precipitation record, people have recorded the largest annual rainfall, which is called "world rain". Its annual average rainfall is 10,000 mm or more.

China Rainpool

The island fire in the northeast of Taiwan, the wind in the Pacific Northeast, and in the northern return line, the highest annual precipitation is 8408 mm.

China's lowest rainfall

Xinjiang's Takson, a warm temperate arvement, annual average precipitation 7 mm

Basic Cases

The average annual precipitation in my country is about 6 + E12 cubic meters, and the average precipitation depth is 628mm, less than 834mm in the global land surface, and is also less than 740mm in Asian land. 56% of these precipitation are consumed for soil and surface water evaporation and plant transpiration, and the remaining 44% is formed. my country's annual average radio is 2.6 + E12 cubic meters, including grate on snow water content of about 5 × 10m. my country's total groundwater has about 8 × 10m, and there is a relationship between surface water and groundwater, and two resources are repeated in parts. After deducting this part of the duplicate water, my country's total average average water resources is about 2.7 + E12 cubic meters m.

Basic Features

Precipitation refers to liquid or solid water that landed from the sky to the ground in a certain period of time, unvapogenated, penetrated, water layer accumulated on the ground depth. The unit is in millimeters, and a decimal number in meteorological observations is taken. Sometimes it is also known as rainfall. Precipitation is generally determined by rain cylinders, so the amount of water contains snow and a small amount of dew, frost and fog. In natural resource research, the common precipitation has the precipitation of the year, the quarter, the month, and the growth period.

China's average annual precipitation is 630 mm, from the coastal to the mainland, the characteristics of the southeast to the northwest:

Regional distribution

Southeast coast Guangdong, Guangxi Eastern, Fujian, Jiangxi and Zhejiang and Taiwan and other regions have 1 500 ~ 2,000 mm; the middle and lower reaches of the Yangtze River are 1 000 ~ 1 600 mm;

Huaihe, Qinling And the annual precipitation of the Liaodong Peninsula is 800 ~ 1 000 mm;

The lower reaches of the Yellow River, the Weihe River Basin, and the northeastern Xing'an Mountain are 500 ~ 750 mm in the eastern region;

Yellow River Westerly 200 ~ 400 mm in the middle and Northeast Daxinganling;

The annual precipitation in the northwestern inland area is 100 ~ 200 mm;

Xinjiang Tarim Basin, Turpan Basin and Qaidam It is less than 50 mm in the basin, and the central center is less than 20 mm.

Season distribution

spring precipitation: in the middle and downstream in the Yangtze River Basin account for 30% to 45% year, Xinjiang accounts for 30% to 35%, and the country is less than 20% in other regions;

Summer precipitation: Summer downstream, South China and Xinjiang area account for 50% year year, other regions are more than 50%; autumn precipitation: 4% year-round, the whole year is less than 20%;

Winter precipitation: downstream of the Yangtze River, most of South China, Xinjiang area account for 10% to 15% year, and other regions are below 10%.