Geographical environment of Lu Zhi town

The stratum of Lu Zhi Town belongs to Late Triassic to Early Cretaceous, and the territory is a weathering and denudation area. In the Late Cretaceous, a faulted basin was formed in Luzhi-Wujiang-Nanxun area, and red sandstone, glutenite, conglomerate and siltstone of inland lake facies (Pukou Formation of Upper Cretaceous) were deposited. The center of the basin is more than one kilometer thick and exposed in Jiangdun Village, Xukou Town, Wuzhong District. Luzhi is a weathering and denudation area, and the geological structure belongs to Weiting-Kunshan fault, which is located on the south side of Weiting-Kunshan line, extending 75 degrees northeast and 30 kilometers long, and is a high-angle normal fault inclined to the south. Jiading area in the east and Huzhou-Suzhou fault zone in the west are the northern boundaries of Luzhi fault depression. The fault is inclined to the south, and the sedimentary thickness of Quaternary, Tertiary and Cretaceous is greater than 1km.

Luzhi landform is Taihu Lake sedimentary plain, which belongs to Danghu Lake network plain in the east of Suzhou. The terrain is low and flat, with an altitude of 3-5 meters, and it slopes slightly upward from west to east. The terrain around Xidang and Hudang is slightly higher, between 4 and 5 meters, and along the Wusong River is between 3 and 4 meters, between the normal water level and the flood level. The town is densely covered with water nets and many lakes. Rivers, ports and rivers divide the ground into many plots of different sizes, and the water surface accounts for more than 30% of the land area. Luzhi town is located in the lower Yangtze paraplatform and Qiantang fold belt, and its geological structure is extremely developed. The geological conditions in the area are good, belonging to loam yellow soil type, and the ground endurance is generally around 12 tons/square meter. The earthquake intensity is less than 6 degrees. Luzhi town area belongs to plain water network area, and belongs to subtropical monsoon climate zone with transitional monsoon climate on the northern edge of central subtropical zone. It has four distinct seasons, mild climate, abundant rainfall, abundant sunshine, obvious rainy season and long frost-free period.

From early April to mid-June, spring lasts about 70 days. It is characterized by alternating cold and warm, slowly rising temperature, changeable weather, hot and cold, spring thunder and late frost. Rainy days are the most, but the precipitation will not be too much, accounting for 30% of the whole year.

From mid-June to late September, summer lasts 100 days. It is characterized by high temperature and the hottest summer solar term every year; There is a lot of lightning, and sometimes there is a bolt from the blue, which hurts people and animals and buildings; The precipitation in the rainy season is the highest in the whole year, accounting for 35% of the whole year.

Autumn lasts about 60 days from the end of September to the end of 1 1. It is characterized by more typhoons, active cold air, less warm air and rapid cooling.

In winter, from 1 1, the cold air in the north began to move southward and the temperature dropped. Generally, there are three or four cold waves every year, and some years are even more, and it will not end until the end of March or early April of the following year, about 120 days. It is characterized by low temperature, with slight cold and severe cold as the coldest solar terms every year; The precipitation is small, accounting for only about 15% of the total annual precipitation.