Geographical environment of Huaiji County

Huaiji, located in the northwest of Guangdong Province, the north of Zhaoqing City and the upper reaches of Suijiang River; Yangshan and Guangning in the east, Deqing in the south, Hezhou in Guangxi in the west, Lianshan and Liannan in the north. It is the main road leading to Guangxi Township in the northwest corner of Guangdong Province, and the gateway for Sichuan, Yunnan and Guizhou in the southwest of China to Guangdong and reach the coastal areas of Hong Kong and Macao. Historically, due to its geographical location, Huaiji was once a corridor for ethnic cultural exchanges at the northern foot of Lingnan Ridge, and also a meeting point of the Silk Road between land and sea. East to Guangzhou, Hong Kong and Macao, west and southwest to Guangxi, south to Zhaoqing and north to Lianshan.

The geographical coordinates of Huaiji are 23 28 ′ 07 ″ ~ 24 23 ′ 30 ″ north latitude and110 52 ′ 09 ″ ~12 30 ′ 49 ″ east longitude, which belongs to subtropical climate. First, the temperature

According to the statistics of the temperature data measured by the county meteorological observatory, the annual average temperature in Huaiji County 1979 to 2000 was 2 1. 1℃ (Celsius. The same below), 1998 has an average maximum of 22.0℃, and 1984 has an average minimum of 20.2℃. The monthly average temperature began to rise month by month in February and reached the highest in July. The average temperature rises gradually from the second weather in February, and reaches the highest in the fourth weather in July. The daily extreme maximum temperature is 39.4℃, which appears in July 1989 and17. The daily extreme minimum temperature is -2.4℃, which appears on199965438+February 23rd.

Second, precipitation

There is abundant rainfall in the county, but the annual and monthly changes are great and the regional distribution is uneven, which has the characteristics of more in the north and less in the south. 1979 to 2000, the average annual rainfall measured by the county meteorological station was1782.0mm, which was the county with the most regional rainfall in Zhaoqing. The maximum annual rainfall is1223 1.7mm in 997, and the minimum is 199 1264.8mm in 0 years. Monthly rainfall 1989 may 552.2 mm, 1989 October 0.0 mm. The maximum daily rainfall is 1999 and 188.9mm on April 26th. Heavy rain (greater than or equal to 50 mm) mainly occurs in the first flood season from April to June, accounting for 70% of the days of heavy rain. If affected by special weather systems such as typhoon depression, there will also be heavy precipitation such as heavy rain in winter.

Third, sunshine and evaporation.

At the location of the County Meteorological Observatory (near Wu Zhou, Guoshang Village, the county town), the measured annual total sunshine hours are1319.4 ~19510.9 hours, the annual average sunshine hours are 1660.2 hours, and the monthly average sunshine hours are the least, 2. The maximum monthly sunshine is 265.8 hours in June 1992 and 7.3 hours in March 1982. The sunshine percentage is the least in March 13%, and the most in June is 53%.

The maximum annual evaporation measured by the county meteorological station is 1986 1563.9mm, and the minimum is198186.1mm, with an annual variation of 377.8mm Generally, the monthly variation is from February.

Fourth, the ground temperature and frost

The annual average ground temperature is 23.9℃; The highest is 24.7℃ in 1998, and the lowest is 22.8℃ in 1995 and 1996. The annual variation range of ground temperature is 1.9℃. The highest monthly average ground temperature is 32.5℃ in July, the lowest is 65438+ 10/3.8℃, and the monthly variation range is 18.7℃. The annual extreme maximum ground temperature is 67.8℃, appearing on July 25th, 1979 at/kloc-0, and the lowest is -6. 1℃, appearing on February 23rd, 1999 at/kloc-0.

The annual average cumulative frost date is 9. 1 day, the average first frost date is 65438+February 15, and the average last frost date is February 2. The earliest frost date is1992165438+1October 10, and the latest frost date is1March 3, 986. The number of frost days is 1984 ~ 1985, only 1 day. The most are 1983 ~ 1984, 1985 ~ 1986, which are 23 days and 25 days respectively. The average frost-free period for many years is 3 10 days.

Five, air pressure and wind

The multi-year average ground pressure measured by the county meteorological station is 1006.9 hectopascals (hectopascals), and the highest is 1029.6 hectopascals, which appeared on February 20th 1996 and February 22nd 1999. The lowest is 985.0hpa, which appeared on June 20th 1985 and July 2nd 1986.

Huaiji county is far from the sea and mountainous. Even if there is no windy weather due to typhoon, there will be local gale due to strong thunderstorm or squall line. Strong winds usually appear in summer and autumn.

Intransitive verb humidity

The annual average relative humidity ranges from 77% to 83%. The annual maximum value of relative humidity is 198 1 year, which is 83%, and the minimum value is 1999 and 2000, which are both 77%. The maximum monthly value of 198 1 in April is 89%, and the minimum monthly value of 1996+0 1 in April is 65%. The air in the county is humid, but the geographical distribution is the largest in the northern forest region, followed by the south-central region and slightly less in the west.

Seven, thunderstorm

The annual average number of thunderstorm days is 89.7 days, the most frequent year is1983 * *118 days, and the youngest is 67 days in 2000. Thunderstorms mainly occur from April to August every year, followed by March and September, and also occur in winter 165438+ 10 to the following year. When a strong thunderstorm occurs, there are often lightning disasters and rainfall.