The weather in Longgang, Wenzhou

Long gang zhen is located in the south bank of Aojiang River, with relatively flat terrain, belonging to coastal siltation plain landform. Geologically, long gang zhen is located in the Mesozoic complex belt in the southeast continent of China, which is a part of the Pacific Rim tectonic-magmatic metallogenic belt. Earthquakes in this area are characterized by weak intensity, small magnitude and low frequency. According to "China Earthquake Sequence Zoning Map (1990)" and "Regulations on the Use of China Earthquake Intensity Zoning Map (1990)" issued by the Ministry of Construction and the State Seismological Bureau, this area belongs to the northeast section of the second-order earthquake in the southeast coast, close to the third-order earthquake zone, and belongs to a region with few earthquakes and weak earthquakes. According to the data of Seismological Bureau of Guangdong Province, recent earthquakes are all less than magnitude 2, so the site stability is generally good under static conditions. The groundwater in the area is shallow, which is obviously affected by tides, and the water level is generally 0.3~2.7m deep. Groundwater is mainly Holocene miscellaneous fill, clay and muddy pore phreatic layer. The aquifer has large thickness, fine particles, poor water permeability and low permeability coefficient. The groundwater in this area meets the lateral seepage of Aojiang River. The recharge mode is mainly tidal water, followed by atmospheric precipitation. The water quality type is CI-N water, which belongs to brackish water-salt water and is non-corrosive to concrete. The distribution of soft soil layer in the site is a bad geological problem. The soil layer is shallow and thick, with poor physical properties and low mechanical strength.

2), engineering geology

The general situation of engineering geology is as follows:

② Layer: clay with a thickness of about1.1m;

③ Layer: Silty soil, about1.4m thick; ;

③-2 layer: silty soil, with a thickness of about 22m；;

③-3 layer: muddy clay with a thickness of about 20m; ;

④ Layer: silty clay, about 4.7m； thick;

⑤- 1 layer: round gravel with a thickness of about 4.7m；;

⑤-2 layer: silty clay with a thickness of about1.4m; ;

⑤-3 layer: pebble: the layer thickness is about 2.4m；;

⑥- 1 layer: clay, with a thickness of about 2.7m；;

⑥-2 layer: silty clay, about11m thick;

⑥-3 layer: clay with a thickness of about11m;

⑥-4 layer: silty clay with a thickness of about1.7m; ;

⑦ Layer: pebble with a thickness of about 9m;

⑧- 1 layer: silty clay, about13.2m thick; ;

⑧-2 layer: clay, with the top elevation of about 107m.

3), meteorology, hydrology

Long gang zhen is located in the Southern Ocean Plain on the south bank of the Aojiang River, which belongs to the subtropical maritime monsoon climate zone, with no severe cold in winter, no coolness in summer, mild and humid, and four distinct seasons.

I. Temperature and sunshine

According to meteorological statistics, the average temperature for many years is 18℃, the extreme minimum temperature is -5℃, and the accumulated temperature for many years is 65 12.5℃. The annual average sunshine hours 1866 hours, sunshine rate of 42%, average first frost of 65438+February 2, final frost of February 7, frost-free period of 277 days, relative humidity of 83%, annual average ground temperature of 2 1℃, and minimum ground temperature of 8.6℃.

B, wind conditions

There are Pingyang wind speed stations in the northern part of Jiangnan marine plain, Nanji wind speed stations and Beiji wind speed stations on the southeast island, and Pipamen marine hydrological station in the south. According to the statistics of many years' data, the average wind speed of Pingyang Station is 2.0m/s, Pipamen Station is 5. 1m/s, Beiji Station is 7.4m/s and Nanji Station is 7.9m/s.. The maximum wind speed is 20.0m/s at Pingyang Station, 35.0m/s at Beiji Station and > 40.8 m/s at Nanji Station. The sea is bigger than the shore, and the shore is bigger than the inland. Wind speed and direction change with seasons, and north wind and northwest wind prevail in winter. South wind and southeast wind prevail in summer.

C, rainfall characteristics

According to the measured data, the annual average rainfall is 1558.3mm, and the seasonal distribution of rainfall is uneven. There are two relative rainy seasons and two relative dry seasons in a year. The first rainy season is from March to June, in which March and April are spring rains, which are caused by the stationary front in South China. At this time, the land cold high drops, the subtropical high moves northward, the cyclone on the peak surface is active, and there is often continuous light rain; May and June were plum rains, because the warm Pacific high-pressure fire pushed to the mainland, and the polar peak moved northward and stagnated in the coastal area of Wenzhou. The rainfall from March to June accounts for about 42% of the annual rainfall (including spring rain 16% and meiyu 26%). The second rainy season is from mid-August to the end of September. During this period, due to the southward shift of polar peak and frequent typhoon activities, the rainfall increased significantly, accounting for about 29% of the annual rainfall. July to mid-August and 10 to February are two relatively dry seasons. The former dry season is controlled by the subtropical high in the North Pacific, with high temperature, sunny heat and little rain, and the annual rainfall accounts for about 10 of the annual rainfall. April to 10 is usually regarded as the flood season, and its rainfall accounts for more than 80% of the annual rainfall, with 165 rainy days throughout the year.

4), soil and vegetation

The surface soil is generally paddy soil, which contains more viscous structure, better water permeability and water holding capacity, and better corrosion resistance and erosion resistance.