Geographical environment of Xinchang county

Xinchang has a subtropical climate, located in the transitional zone between the middle subtropical zone and the north subtropical zone, with mild and humid climate and distinct four seasons. Rain and heat are synchronized in early spring and summer, but sunny and hot in midsummer, complementary light and temperature in autumn and winter, and more disastrous weather. The annual sunshine is about 1900 hours, the annual average temperature is 16.6℃, the annual precipitation is 1500mm, and the frost-free period is 240 days. At the same time, it has typical mountain climate characteristics, and there are obvious differences between horizontal and vertical directions.

The four seasons are long in winter and summer and short in spring and autumn. In spring, the cold and warm air mass in the county advances and retreats, and it is cold and hot, with changeable weather and continuous rain. There is a lot of precipitation, accounting for 26% ~ 35% of the whole year. In March and April, there was a "cold spring". In early summer, "Meiyu" is often accompanied by heavy precipitation, and sometimes it appears early in late May. From July to August in midsummer, the Pacific subtropical high enters the territory, and the weather is sunny and hot, resulting in "summer drought", which is often caused by typhoons, rainstorms and storms, accompanied by precipitation to alleviate the drought. There are often local thunderstorms in the afternoon, with occasional hail, strong winds and heavy rain. Precipitation accounts for about 37% of the whole year. In early autumn, cold and warm air masses conflict, often cold and rainy. After mid-autumn, affected by the low and high pressure in the lower reaches of the Yangtze River, the air is crisp in autumn, and "autumn drought" is common, and "Xiaoyangchun" appears in 10. Precipitation accounts for 14%. In winter, the high tide enters the Sanjiang Valley through the northwest valley plain (basin), and the temperature drops sharply, and the precipitation accounts for 23% of the whole year. topography

Xinchang is located in the upper reaches of Cao 'e River, and its landform features are "eight mountains, half water and half fields".

The main peaks in Xinchang County are all above 600 meters above sea level, and the highest peak is Juvenile Bodhi Peak, with an altitude of 996 meters. Siming Mountain Range enters from the northeast and is located in Shaxi Mountain Range. The two branches of Tiantai Mountain range, which entered from south-central China, were called "the main mountain of one city" in ancient times, and meandered to Anding Mountain, forming a mountain range from Ruo 'ao to the east of Huishan. Huiji Mountain and Pandashan Mountain enter the territory from the southwest, crossing Anshan in Jingping Township and Xikeng in Jingling Town, forming the southern foot of Jingling Mountain. The central part is a hilly platform, generally a basalt platform, with an altitude of 250 to 500 meters. There are large areas such as Huishan, Dashiju, Mengjiatang and Dunshan, with steep edges.

Xinchang county is a part of low mountains and hills in Zhejiang and Fujian. The eastern part is dominated by low mountains and hills, the main peak is above 800 meters above sea level, and the central part is mostly a hilly platform below 300 meters, which descends from south to north, and valleys and low mountains alternate in the northwest, with the altitude below 150 meters, and the lowest altitude is only 28 meters. According to statistics, the mountainous area of the county is 382.49 square kilometers, accounting for 3 1.7% of the total area, the hilly platform area is 765.48 square meters, accounting for 62.25% of the total area, and the basin area is 73.56 square kilometers, accounting for 6.58% of the total area. According to the land resources survey of 1989- 1992, the total land area of the county is 1820800 mu, of which 50 1700 mu is cultivated land (including ridges), accounting for 27.56%. Garden178,000 mu, accounting for 7.03%; Woodland 904 1 10,000 mu, accounting for1.08%; The water area is 8 1 1 ten thousand mu, accounting for 4.45%; Unused land117200mu, accounting for 6.44%.

river

Xinchang County has three major rivers, namely Chengtan, Xinchang and Huang Ze, with a drainage area of 1.209 square kilometers, 73 tributaries, 455.6 kilometers long and a river network density of 0.38 kilometers per square kilometer. It is a typical mountain river with many tributaries, large drop and rich hydraulic resources. Chengtan River, New Yangtze River and Huangzejiang River flow in a fan shape to the northwest and join Cao 'e River.

Chengtanjiang

Chengtan River is the main stream of Cao 'e River, which originates from Jiangongling (870 meters above sea level) in Pan 'an County. Originally called Tengteng River, it was called Jiaxi after crossing Wuzhangyan Reservoir, and entered the country at 1 km northwest of Shiniankeng, Huishan Town, this county. From south to north, it flows through Jingling, Chengtan and Meizhu, and enters Shengzhou City at Baidu River in Tiandong, with a total length of 965438+. Xinchang covers an area of 44. 1 km, with a drainage area of 388.63 square kilometers, accounting for 3 1.8% of the county's total area. The width of the upstream and downstream rivers is about 80 to140m respectively. More than 60% of the county's arable land and more than 70% of the population are concentrated on both sides of the strait. After liberation, Shimen Reservoir and Menxi Reservoir were built in the upper reaches of the county, which provided a guarantee for controlling and alleviating the flood disaster along the river.

Xinchanghe

Xinchang River is a tributary of Cao 'e River. Originated in Huading Mountain on the Tiantai, it enters Dazhuyuan via Liang Shi Waterfall and Cisheng in Shiqiao Township, Maoyang River and Huangtan River in Shanghai Village of Xiaosheng Town, obliquely passes through the central part of the county to the northwest, and enters Shengzhou urban area via Dashiju Town, Yulin Street, Nanming Street and Qixing Street to the northwest of Houxi Village, with a total length of 67.3 kilometers. Xinchang has a territory of 48.9 kilometers and a drainage area of 433 square kilometers. It accounts for 36.3% of the county's total area, with an average river width of about 60 meters and a natural drop of 173 meters. There is Zhao Chang Changku in the middle reaches, also known as Luozhou Lake, which is a provincial-level scenic spot.

Huangzejiang

Huang, formerly known as Jugenxi, originated in Patience Ridge, Qiaoying Township (3 kilometers southeast of Zhongxi Village). Through Dashimao Town, the bamboo dike in Xinlin Township is called Guangxi, through Qincun Village in Yulin Street, called Hengxi, through Changshan Village, called Huangzejiang, into Shengzhou to Pukou, and Huang Ze into Caoejiang, with a total length of 70.6 kilometers. Xinchang territory is 50.6 kilometers. The basin covers an area of 378 square kilometers, accounting for 30.9% of the county's total area. The average river width is about 70 meters, and the natural drop is 257 meters. There is Qiaoying Reservoir upstream.