Climate and hydrology

Shijiazhuang is located in a semi-humid and semi-arid area, with a continental semi-humid monsoon climate of warm temperate zone. The annual average temperature 13.30℃, with the highest temperature of 26.90℃ in July and the lowest temperature of -2.40℃ in June. The extreme maximum temperature is 42.90℃, and the extreme minimum temperature is-19.80℃. The annual average precipitation is 534.60mm, the annual maximum precipitation is 1097. 10mm, the annual minimum precipitation is 226. 10mm, the monthly maximum precipitation is 75 1.90mm, the daily maximum precipitation is 359.30mm, and the hourly maximum precipitation is 92.90mm The annual average sunshine hours are 25 13.90 hours; The annual average frost-free period is 197 days, the average date of the first frost is 65438+10.20, and the average date of the last frost is April 5. The maximum frozen soil depth over the years is 56 cm.

Figure1.1.1955 ~ 2003 wind frequency chart

The seasonal variation of solar radiation is remarkable, with frequent high and low pressure activities on the ground, distinct four seasons, wide disparity between cold and hot, long summer and winter, short spring and autumn, concentrated rainfall and obvious wet and dry periods. Spring is dry and windy, summer is hot and rainy, autumn is sunny and cold, and winter is cold and partly cloudy. The total sunshine hours in the whole year are1916.40 ~ 2571.20 hours, in which there is plenty of sunshine in spring and summer and less sunshine in autumn and winter.

With the development of the city, influenced by urban buildings and vegetation, the ground roughness has changed greatly, which makes the urban wind frequency change, especially the number of windy days decreases. Due to the blocking effect of the northwest mountains, the static wind frequency is 28%.

The wind direction in Shijiazhuang city is obviously dominant, and the dominant wind directions are north wind and south wind, as shown in figure 1. 1. This is mainly because Shijiazhuang has a continental monsoon climate with seasonal changes in wind direction. At the same time, because Shijiazhuang is adjacent to Taihang Mountain in the west and open plain in the southeast, the characteristics of valley wind are obvious when there is no obvious weather system influence.

Groundwater in Shijiazhuang city is divided into three water-bearing rock series, including quaternary loose rock pore water-bearing rock series; Neoproterozoic, Mesoproterozoic, Cambrian and Ordovician limestone fissure karst water-bearing rock series; Due to the continuous over-exploitation of groundwater in Neoproterozoic metamorphic fractured water-bearing rock series for many years, the groundwater depth in Shijiazhuang City has been greatly reduced, and the industrial mining funnel in the urban area and the agricultural mining funnel in Gaoyi County-Zhaoxian County have been formed in the plain area.

Shijiazhuang has an average annual water resource of 2.24 billion cubic meters, with a per capita water resource of 65,438+0.8 of the national average, which belongs to an extremely poor water area.

Shijiazhuang belongs to Haihe River Basin, and the rivers in the territory belong to Daqinghe River System and Ziya River System. The main rivers are Dasha River, Ci River-wood road ditch, Hutuo River, Chan River, Huaihe River and Yi River. Dashahe River and Cihe-wood road ditch in the north belong to Daqing River system. Hutuo River, Hutuo River, Huaihe River and Weihe River in the south-central part belong to Ziya River system. The total drainage area is 33,500 square kilometers. There are 228 large and small reservoirs in China, including 4 large reservoirs, namely Gangnan Reservoir, Huangbizhuang Reservoir, Koukou Reservoir and Hengshanling Reservoir. The eight medium-sized reservoirs are Bayi Reservoir (Beaulieu Lake), Honglingjin Reservoir, Shiban Reservoir, Xiaguan Reservoir, Yanchuan Reservoir, Baicaoping Reservoir, Nanpingwang Reservoir and Zhanghewan Reservoir.