Administrative divisions of Yi 'an District

190 Tongling county has 4 towns, 14 townships, 13 neighborhood committees and 199 village committees.

1991August, Taiping Street Neighborhood Committee in Taiping Township was established.

1February, 1992, the Fengdan neighborhood committee of Xinqiao Township and the Dongdian Street neighborhood committee of Dongdian Township were established.

1993, Xihu Town was built by Xihu Township.

1994 Xinqiao Township, Zhucun Town and Dongdian Township were abolished, and xinqiao town, Zhucun Town and Dongdian Town were newly built.

1995, West Lake Xifeng Neighborhood Committee was established.

1June, 1996, Shun Zhen 'an Town Jindai Neighborhood Committee and Zhen Wanjishan Neighborhood Committee were established.

In August, 1996, Zhucun neighborhood committee was established.

1999 10, the industrial and rural areas of Chengguan Town near the city, near the city and Xihu Town in Caidai County are classified as Shizishan District of Tongling City.

By the end of 2000, * * had 8 towns, 10 townships, 20 neighborhood committees and 196 village committees.

At the end of 200 1, the whole system of Xihu town was incorporated into the lion mountain area.

In May 2004, the administrative division was adjusted, and the number of townships was adjusted from 10 to 4 townships and 5 towns.

At the end of 2004, the adjusted integration system of Datong Town was brought into the suburbs.

In 2008, there were four townships: Donglian Township (formed by the merger of former Liutan and Yongfeng Township), Xilian Township (formed by the merger of former Taiping, Heping and Zhongcang Township), Xuba Township (formed by the merger of former Xuba and Anping Township), Laozhou Township, Wusong Town (formerly Chengguan Town) and Shun 'an Town (formed by the merger of former Shun 'an and xinqiao town). Due to the influence of neotectonic movement, the Yangtze River folds declined and the south bank topography gradually rose. Frequent folds and fault movements promote strong fault block differentiation, forming low mountains, hills, valleys, undulating hills and alluvial plains along the river. The landform shows obvious regional differences and transitional changes. The total terrain in the territory is high in the south and low in the north, and the middle part is the transition zone between the north and the south. According to the formation characteristics, morphological characteristics and composition of geomorphology, it can be divided into three types of areas. From south to north, the terrain is low mountain area, hilly area and continental polder area.

The low mountainous areas in the south include Xipaifeng, Huangmuling and the area south of Lion Mountain, accounting for about 40% of the whole area, with a higher altitude, generally between 200 and 500 meters. Zhongming, Jinlang, Xinqiao, Dongdian, Zhucun and other places have developed some fault blocks and low mountains due to the influence of many tectonic movements. The low mountains in the territory are distributed in the northeast, mostly folded, and a few are fault mountains, with a general slope of about 25 ~ 30. The mountain is relatively complete and gradually inclines from southwest to northeast. The rocks that make up the low mountains are mainly granite and diorite of Yanshan movement, limestone and siliceous rocks of Triassic and Permian, and timely sandstone, sandy shale and siltstone of upper, middle and upper Devonian of Zhimao system.

The hilly area in the middle part includes the south of Xingou, Wang Huayuan, Louyushan and Cuijia, as well as Chengguan, Liutan, Zhongcang, West Lake, Zhongming and Xinqiao, accounting for about 30% of the total area. The altitude is less than 200 meters, mostly 50 ~ 150 meters. The hilly area in the middle is a transitional zone between north and south, and the hills are distributed in a northeast belt. The average slope of the ground is smaller than that in the south, generally at 15 ~ 20, and only the hills formed by faults are steep. The ground was cut into pieces, and there were a series of gullies and valleys. The terrain is slightly undulating, and gradually decreases from north to Linping original polder area, with a relative elevation of 20 meters to 30 meters. It is mainly composed of Quaternary middle-upper Pleistocene red clay and Xiashu loess, accompanied by Triassic, Permian limestone and Tertiary purple gravel. Cretaceous glutenite is distributed in frog-shaped hills in Shun 'an, silver carp hill in Zhongming, hilly hills beside Chengguan River and newly-built glorious villages. The long and narrow valley plains (fields) formed along the Shun 'an River and Xinqiao River are composed of modern river alluvium. The thickness is generally about 5 meters.

Tongling County in northern Zhou Wei has the lowest terrain, which is formed by the alluvial action of the Yangtze River and its tributaries. The scope includes Datong, Laozhou, Anping, Xuba, Taiping, Yongfeng and Heping, as well as parts of Zhongming, Shun 'an, Chengguan, Liutan and West Lake, accounting for about 30% of the whole area. This area has been in recession since the Quaternary, and the Yangtze River and its tributaries carry a lot of sediment to form deep sediments. Since the Holocene, the area has generally shown a downward trend, with sandbars, Jiang Xinzhou and swamp lakes formed along the river, with the elevation less than10m and the ground slope less than 1/5000. The main components in this area are Holocene modern river alluvium and lake sediments. Yi 'an District belongs to the northern subtropical monsoon transition zone, with four distinct seasons, mild and humid climate throughout the year, moderate rainfall, high humidity, abundant sunshine, long frost-free period and remarkable monsoon climate. Due to the climate transition, cold and warm air meet frequently, the temperature difference between winter and summer is significant, and the precipitation varies greatly during the year, and severe weather such as drought, waterlogging, strong wind and hail often occurs.

Climatic characteristics of the four seasons: in spring, the westerly belt at high altitude gradually withdraws northward, the cold high pressure weakens and contracts northward, the warm high pressure strengthens and moves northward, the temperature jumps and rises, and the weather is changeable, sometimes sunny and rainy, sometimes warm and sometimes cold. When a cold wave or strong cold air invades the south, it is often accompanied by a rainy and windy cooling process, resulting in "late spring cold" weather. Summer entered the summer at the end of May, and the subtropical high in the western Pacific jumped northward, and the warm and humid airflow was active. In mid-June, the rainy season is continuous and the precipitation intensity is high, which is easy to cause floods. In autumn, the subtropical high weakened and gradually withdrew to the south, and the cold high force increased to the south, with rapid cooling, increased daily temperature difference and less rain. It is easy to cause autumn drought. When strong cold air invades the south, it often becomes low temperature and rainy in autumn. Winter is controlled by the high pressure in Inner Mongolia, and the weather is sunny, dry and cold, mainly northerly. Frost or frost occurs frequently, and it snows every year, and it snows in most years.

The annual average temperature 16. 1℃ varies greatly during the year. The average temperature in the highest year (196 1) is 17. 1℃, and the average temperature in the lowest year (1980) is 65438+. The annual average ground temperature is 18.8℃. The highest is 20. 1℃ in 1978, and the lowest is 17.7℃ in 1989. The annual sunshine hours are 4,427.2 hours in normal years and 4,438.3 hours in leap years. The average annual frost-free period is 247 days, with the longest being 276 days (1960) and the shortest being 2 12 days (1966). The average annual precipitation after rainfall is1384.7mm. The average annual rainfall days over the years are 136.3 days. The annual average snowfall days are 1 1.3 days, the maximum snowfall days are 2 1 day (1973 ~ 1974), and the minimum snowfall days are 2 days (1970 ~/kloc). The annual average wind speed is 3.1m/s.

Soil types and distribution The soil types in this county are divided into 7 soil types, 13 subcategories, 49 soil genera and 85 soil types.

Due to the different landform types and local topography, the distribution characteristics of various soils are also different. The soil types in hilly areas of central and southern China are mainly yellow red soil, brown calcareous soil, paddy soil and small areas of tidal soil and purple soil. Distribution varies with topography, usually from low hills to alluvial areas, mainly yellow red soil and paddy soil; The inter-mountain valley is mainly composed of xianglime soil field, gravel mud field and gravel sand mud field; Sandy mud fields and calcareous mud-bone fields dominate the banks of the river. White soil fields with cascade distribution on both sides; Lime slag field is distributed annularly at the foot of limestone mountain. Fluvo-aquic soil is the main dry farming soil type in the northern coastal plain. Along one side of the main river, Jiang Xinzhou is followed by river sand, green sand, lime sand and lime soil, and the beaches along the river are followed by lime sand, lime sand and lime soil, which are connected with paddy soil and mortar fields. Paddy soil is also the main soil type. Usually, lake mud fields are distributed in secondary terraced polder fields, while mud fields, moss mud fields and green mud fields are distributed in flat and low-lying areas.