Geographical environment of Dongkou county

Dongkou County belongs to subtropical monsoon humid climate, with four distinct seasons, sufficient heat, short hot and cold summer time and long crop growth period. Spring is changeable in temperature and cold, with frequent cold current activities; It is rainy in late spring and early summer, and dry in early summer and autumn; Mountains and hills. Seasonal changes. The climate difference between Xuefeng Mountain area in the northwest and Qiugang area in the southeast is obvious. Northwest mountainous area belongs to subtropical humid and cool area, with abundant rainfall, poor heat resources, rainy spring and summer, ice and snow in winter, cool temperature in midsummer and great vertical climate difference. The hilly area in the southeast belongs to subtropical humid temperate zone, with rainy spring, hail, thunderstorm and strong wind, drought in summer and autumn, different hilly terrain and obvious microclimate difference.

Temperature: average annual temperature in Dongkou County 16.6℃. The hottest month of the year is July, with an average temperature of 27.3℃. Leng Yue has an annual average temperature of 5.4℃ 1 month. The average number of days with daily minimum temperature ≤0℃ is only 16.2 days.

Precipitation: the average annual precipitation in Dongkou County is 149 1mm, and the average annual rainfall days are 180 days. Early March to April is the spring rain period, with more rainy days and less precipitation intensity. May to the end of June is the rainy season, with increased precipitation intensity and frequent rainstorms, with an average monthly rainfall of more than 200 mm. From the end of September to the beginning of 1 1 month, the rainfall in rainy days increased, and the average rainfall in 1 month was above100 mm.

Sunshine: the annual sunshine in Dongkou County is1173.5 ~1705.5 hours, with an annual variation of 532.0 hours, an average annual sunshine 1424.0 hours and an annual sunshine percentage of 32%. Affected by topography, sunshine hours gradually decrease from southeast to northwest. The sunshine hours in the northwest mountainous area are 5 1 hour and 6 12 hours less than those in the central Pinggang area and the eastern Qiugang area, respectively.

Evaporation: the annual evaporation in Dongkou County is between1022.0 ~1447.5mm, with an annual variation of 425.5mm. The precipitation in spring, summer and winter is greater than the evaporation, and the evaporation in autumn is greater than the precipitation.

Frost: The frost-free period in Dongkou County is about 290 days. The first frost is usually in the middle of June of the first year 165438+ 10, and the final frost is usually in the first ten days of March of the second year.

Snow: The average snowfall in Dongkou County is 1 1.8 days. The first snow usually appears in the middle of 10, and the last snow appears in the late March.

Wind: The wind direction in Dongkou County changes with the seasons. In winter (11~ April), easterly winds predominate, followed by northerly winds, and in summer (5 ~ 10), westerly winds predominate, followed by southerly winds. The most common wind directions are east wind and west wind, followed by northeast wind. The average wind speed over the years is1.3m/s.

There are more than 130 streams in Dongkou county, of which 80 streams are more than 5 kilometers, most of which originate from Xuefeng Mountain in the northwest and flow to the southeast and northwest, belonging to Ziheyuan water system respectively. There are 7 1 river injected into Zishui River System, and the basin area of the county is 1 949.584 square kilometers, accounting for 88.6% of the total area of Dongkou County. Nine of them are injected into the Yuanshui River system, mostly in Luoxi Yao Township, with a drainage area of 249.8 square kilometers, accounting for 1 1.4% of the total area of Dongkou County.

Liaoshui: Liaoshui Irrigation District is located in the south of the county, west to the eastern foot of Xuefeng Mountain, north to Pingxi River, south to Liaoshui River and east to the intersection of Liaoshui River and Pingxi River. It is a narrow triangle, which irrigates eight towns and a state-owned farm in Dongkou County, and the designed irrigation area is 186970 mu. The total length of the main stream is 92km, and the drainage area is 1 14 1 km2.

Pingxi River: Pingxi River was called Xiakou Water in ancient times, also known as Dongkou Water. Originated in Dawan, Qianyang County, it entered the Jiangkou, Dongkou County, passed through Yuexi, Dongkou Town, Dongkou County and Zhu Shi, and then merged into the water from the left bank in Longtanpu, Shijiang Town. The total length of the main stream is 93 kilometers, the drop is 26 1 m, the riverbed is 70.8 meters wide, the annual average flow of the estuary is 76 cubic meters per second, and the basin area is 2269 square kilometers.

Huangni River: a tributary of Pingxi River, called Wangni River in ancient times, also known as Shanmen Water. It runs through the northeast of the county. The Huangnihe River originates from baimashan, Longhui County, flows through Tongshan Township, Shanmen Town and Shuidong Township in Dongkou County, and flows into Pingxi from the left bank at Chuanshishan. The total length of the main stream is 4 1km, and the drainage area is 436 square kilometers.

Gong Xihe: A tributary of Yuanshui River, which originates from Zhangjiachong, Suining County, passes through Shuikou and Luoxi, Dongkou County, and leaves the fish pond, with a total length of 64 kilometers and a drainage area of 488 square kilometers. The county's inland river is18.5km long, with a drainage area of 249.8km2. ..

(refer to the atlas of Dongkou Hall in summer)