Geographical environment of Qixian county

Cambrian and Ordovician strata are widely exposed in Qixian county, and Precambrian strata are rarely exposed, only Archean metamorphic rocks in bedrock area are seen, which are in unconformity contact with Sinian and Xuanwu systems. The Sinian system is only tens of meters thick or even missing. Upper Ordovician to Lower Carboniferous lost Paleozoic. Due to the Cenozoic coverage, the Upper Carboniferous is not completely exposed, and the Permian is not exposed, which can only be seen from the borehole. The Cenozoic includes Upper Tertiary, Lower Tertiary and Quaternary.

Qixian county is high in the northwest and low in the southeast, with mountains in the west and northwest, plains and depressions in the east and southeast, surrounded by water on three sides, and all inland rivers converge to the southeast. The elevation of western mountainous areas is mostly in 100 ~ 1000 meters, and the highest elevation is 10 19 meters. The eastern Pingbo area is below 100 meters above sea level, with a minimum elevation of 63.8 meters and a height difference of 955.2 meters. There are seven kinds of ground slopes: flat slope, gentle slope, slope, steep slope, steep slope, dangerous slope and steep slope, all of which change with the change of hill grade.

Qixian county is rich in landforms and resources. The terrain is high in the west and low in the east, with mountains, hills, plains and depressions, of which the hilly area accounts for two-thirds. Qixian county is located in the north temperate zone, and there are obvious seasonal changes in the territory. The longest sunshine duration from summer solstice is 14 hours and 35 minutes. The shortest winter solstice is 9 hours and 44 minutes, and the vernal equinox and autumn equinox are 12 hours. The annual average ground temperature in Qixian County is 16.7℃, the highest average in June is 32. 1℃, and the coldest average in June is -0.8℃. The annual average daily temperature in China is 13.9℃. The warmest year is 14.7℃, and the coldest year is 13.0℃. The average temperature in July is 26.9℃, and that in January is 0.9℃. The average temperature is 65438 04.2℃ in spring, 26.2℃ in summer, 65438 04.3℃ in autumn and 0.5℃ in winter.

The average annual frost-free period in Qixian County is 209 days, with the longest being 233 days (1965) and the shortest being 177 days (198 1 year). The average first frost date is 65438+1October 27th, the earliest is 65438+1October 9th (198 1 year), and the latest is165438+1year. The average last frost date is April 3rd, the earliest is March 23rd (1977), and the latest is April 24th (1988, 1990). The average annual precipitation (including rain, snow and hail) in Qixian County is 605.2 mm ... The largest 1 164 mm is in 1963, and the smallest 1965 is only 360.6 mm ... Qixian County is located between Taihang Mountain and the continuous Huolonggang in Xunxian County, forming a narrow place. The wind direction is mostly north-south, and the wind force is mostly 4.5. In the year of 20 10, the cultivated land in Qixian county was 322,900 mu, and the per capita of farmers was 1.5 mu. In addition, there are 365,000 mu of barren hills, hills and ditches where trees and grass can be planted to develop forestry and animal husbandry. In addition, rivers, reservoirs, ditches and pits cover an area of more than 34,000 mu, and the water surface can develop fishery and aquatic cash crops.

In 20 10, the total soil area in Qixian county was 720,000 mu, which was divided into 3 soil types, 7 subtypes, 14 soil genera and 32 soil species. Among them, there are 650,000 mu of cinnamon soil, 70,000 mu of fluvo-aquic soil and more than 200 mu of paddy soil. Qixian county belongs to Haihe river basin. Main rivers 15, with a total length of 222.9 kilometers. Among them, there are 4 boundary rivers with a total length of 56.7 kilometers, inland rivers 1 1 with a total length of 166.2 kilometers, and 773 drainage ditches in Bowa area with a total length of 195 kilometers. Qihe River is the largest boundary river, while Zheshan River (Australian water), Bianhe River (Meigou) and Zhaojiaqu River are the largest inland rivers. Qixian county is rich in water resources and good in water quality, but its spatial and geographical distribution is uneven. The annual average total precipitation is 4 1 10,000 cubic meters. Excluding evaporation and infiltration, the average runoff depth is1.62mm, and the total annual runoff is 8437 1 10,000 cubic meters. Surface runoff mostly occurs in rainy season, especially in flood season. Rivers such as Shunside River, Qihe River, Zhuxiaohe River and Bamigou River, except for partial infiltration to recharge groundwater, mostly flow abroad. The actual annual consumption is only 1 1 ten thousand cubic meters, accounting for only 13% of the total annual runoff. There have been more than 20 falls over 5 meters, and these falls have produced certain force and energy. Water mill, water mill and hydraulic pump can be installed, and small hydropower stations can be built with large drop.

Most springs in the county have excellent water quality, such as Taihe Spring, Shuimu Cave Spring, Lingshan Spring and Fish Spring. , containing trace elements beneficial to human body. Some springs, such as Yangjinzhuang and Tiexi, can produce mineral water after preliminary verification by the testing department. There are many hills in Qixian county, and there are springs overflowing on both sides of the ditch river. According to the investigation in 1980, there are 77 active springs in the whole territory. There are 48 perennial flowing springs and 29 seasonal springs.