Natural conditions in Chenzhou

Chenzhou City is located at the northern foot of Nanling Mountain, in the subtropical climate zone of 24 53 ′-26 50 ′ north latitude, and its terrain is inclined from southeast to northwest, showing a "mountain" shape, which is high in the east and low in the west, high in the south and low in the north. Several main mountain systems of Nanling Mountains run northeast-southwest in Chenzhou, which block and lift the cold air from north to south, and act as a barrier to the warm and humid airflow from southwest, so that the climate of Chenzhou City has obvious local microclimate characteristics in addition to the main characteristics of subtropical humid climate. That is to say, it has the characteristics of light, heat and water in the same season and four distinct seasons, and there is also a microclimate in which the climatic elements such as light, heat and water are redistributed due to the influence of topography, resulting in more mountainous areas with high temperature in the south and low temperature in the north, less precipitation in the high temperature east of the west, less flat hilly areas, and more local warm areas and precipitation concentration areas. Controlled by Mongolian high pressure in winter and spring, the continental monsoon in the north prevails in Chenzhou city, with more cold air activities; Summer and autumn are controlled by the western Pacific subtropical high and Indian low, and the tropical maritime humid monsoon prevailing in the south is characterized by hot Leng Xia in winter, abundant spring rain, long high temperature period in summer and crisp autumn, but sometimes continuous autumn rain and diverse mountain climate.

Chenzhou has four distinct seasons, with long winter and summer and short spring and autumn in hilly areas. Winter is long in mountainous areas, and spring, summer and autumn are short. In flat hilly areas, from winter to spring and from spring to summer, the south is 2-4 days earlier than the north.

Spring precipitation is the most season in a year, accounting for 37.3% of the annual precipitation. The sunshine hours are 220-290 hours, and the distribution characteristics of sunshine hours are less in the south and more in the north.

The most remarkable features of spring climate are early spring, rapid temperature rise, abundant precipitation, rainy weather and hail and strong wind.

The hot summer climate is prone to midsummer drought, heavy rain and floods. Because the average altitude is over 400 meters, hilly areas and mountainous areas are cooler than neighboring cities. The cool climate in mountainous areas is more prominent.

Autumn in Chenzhou is dominated by crisp air, with strong sunshine, less precipitation and more sunny days, which is prone to autumn drought. In a few years, autumn rain will be accompanied by cold dew wind.

Winter climate is characterized by less cold, less rain and snow, and the temperature is higher than that of surrounding cities.

The coldest month in a year is 65438+ 10, with an average temperature of 6.5℃, and the hottest month is July, with an average temperature of 27.8℃. With the arrival of spring, the temperature rises rapidly in March and April. After midsummer, the temperature drops. From September to 65438+February, the temperature drops by as much as 5℃ every month to enter winter. It reflects that Chenzhou belongs to continental climate.

[Edit this paragraph] Geography and Hydrology

topography

Chenzhou City is located in the southeast of Hunan Province, at the intersection of Nanling Mountain and Luo Xiao Mountain, and at the intersection of Yangtze River and Pearl River. The landform in the territory is complex and diverse, mainly hills, with equal hills and less water surface. Hilly areas account for nearly three quarters of the total area.

The landform of Chenzhou is generally that the southeast mountains overlap and are surrounded by mountains on all sides; The mountains in the west are low and open to the north, and the hills, plains and hills in the middle crisscross. The terrain inclines from southeast to northwest, with Luo Xiao Mountain extending from north to south in the east, with the highest peak at 206 1.3m; Nanling Mountain in the south, with the highest peak at1913.8m.. The western part crosses the Chen Dao Basin, and the northern part is penetrated by the Right Basin and the Chayong Basin, forming a low-level terrain with an altitude of 200-400 meters and a lowest point of 70 meters.

The land stratigraphic structure of the city: the flat land, hills and hills are mainly Quaternary loose deposits, red rocks, limestone and sand shale; These mountains are composed of granite, metamorphic rocks, limestone and sand shale. Soil is divided into 10 soil types, 23 subtypes, 102 soil genera and 343 soil species. Among them, red soil, yellow soil and yellow brown soil account for more than 70% of the soil plane distribution.

The land is divided by topography: hills are 2066 square kilometers, hills are 397 1 square kilometers, plains are 2355 square kilometers, mountains are 10542 square kilometers and water surface is 454 square kilometers; It is divided into cultivated land 23 14 square kilometers, garden land 9 1 square kilometers, woodland 12990 square kilometers, grassland 1.847 square kilometers, urban and rural residential land 373 square kilometers, industrial and mining land 52 square kilometers, and traffic land16544.

Vegetation in the whole city: evergreen broad-leaved forest below 650m, evergreen and deciduous mixed forest below 650- 1000m, deciduous broad-leaved forest below 1000- 1500m, and shrub grass above 1500m. The forest area is 6.5438+0.065 million hectares, accounting for 62.3% of the city's total area.

The total area of soil erosion in the city is 4131.61km2, accounting for 2 1.35% of the total area, of which the lightly eroded area is1996.18km2; The area of moderate erosion loss is 1953.39 square kilometers; The loss area of strength erosion is 160.89 square kilometers; The area of extreme erosion loss is 2 1. 15 square kilometers.

Hydrological water system

The whole city of Chenzhou belongs to the Yangtze River and the Pearl River, and the Ganjiang River, Xiangjiang River and Beijiang River. The Yangtze River basin covers an area of 157 18.8 square kilometers, and the Pearl River basin covers an area of 3,674.5 square kilometers. Rivers in the territory are developed and distributed radially and densely. There are 423 rivers with a drainage area exceeding 10 km2, 27 rivers with a drainage area exceeding 50 km2, 62 rivers with a drainage area exceeding 100 km2, and 3 rivers with a drainage area exceeding 500 km2, with a drainage area exceeding 100.

A, xiangjiang river system:

The drainage area is 15027.3 km2, and there are 3 rivers19, with an area of 10 km2. The main rivers are:

1. Fuling water: The human form originated in Lanshan County flows into Xiangjiang River at the junction of Changning County and leiyang city via Jiahe and Guiyang, with a drainage area of 6,623 square kilometers, a main stream length of 223 kilometers and an average riverbed gradient of 0.8‰, which controls most areas of Linwu, Jiahe and Guiyang counties in this city. The rainwater collection area of this city is 3326.5 square kilometers.

2. Thunder water: tobacco and bamboo bags originated in Guidong County and flowed into Xiangjiang River through Rucheng, Zixing, Yongxing, Leiyang and Leihekou in Hengyang City. The drainage area is 1 1783 square kilometers, the main stream is 453 kilometers long, and the average riverbed gradient is 0.77‰, which controls Guidong, Rucheng, Zixing, Suxian and Beifang in this city.

3. Yongle River: It originates from Maoji Mountain in Gong Peng Temple in Zixing City, flows into Mishui in Caoshi, Hengdong through Yongxing and Anren, and then flows into Xiangjiang River. The total area of the basin is 2572 square kilometers, the length of the main stream is 2 10 kilometers, and the average riverbed gradient is 1.9‰, which controls a small part of Zixing and Yongxing in this city and most of Anren. The rainwater collection area of this city is 2535.

Second, the Ganjiang River system:

Control the city's river basin area of 69 1.5 square kilometers, and there are 20 rivers with an area of 10 square kilometers. The main rivers are:

1. Keelung River: Originated in Niumutang, Rucheng County, and injected into the upper reaches of Jiangxi Province in Keelung Township. The rainwater storage area of this city is 50 1.8 square kilometers, the main stream is 50 kilometers long, and the average riverbed gradient is 5.28‰.

2. Quanjiang: Toutouyinfa originated in Qiaotou Township, Guidong County, and flowed into Jiangxi in Yuanming, Dida Township. The rainwater harvesting area of this city is 189.7 square kilometers, the main stream is 23.9 kilometers long, and the average riverbed gradient is 57‰.

Three, the Pearl River system:

Control the city's river basin area of 3674.5 square kilometers, 84 rivers, with an area of 10 square kilometers. The main rivers are:

1. Wushui: Wushui system, a first-class tributary of Beijiang River system in the Pearl River Basin, originated in Sanfengling, Linwu County and flowed into Guangdong Province through Luojiadu, Yizhang County. The rainwater storage area of this city is 3365.7 square kilometers, the main stream is 147 kilometers long, and the average gradient is 1.49‰. Among them, South Huaxi (Leshui River), a secondary tributary of the Beijiang River system, originated in Yangzikeng, Yizhang County, and flowed into Wushui, Shuikou, Guangdong Province, with a drainage area of 1.223 square kilometers, a length of main stream of1.654,38+0.5 kilometers, and an average riverbed gradient of 3.28‰, which controls the rainwater collection area in Yizhang County of this city.

2. Town water: It originates from the Jiulong River in Rucheng County, flows into Guangdong at the mouth of the city, and then flows into Beijiang River. The rainwater collection area of this city is controlled to be 308.8 square kilometers, the length of the main stream is 22.3 kilometers, and the average riverbed gradient is 15.0‰.

Chenzhou is rich in water resources, with a total water resource of 220.71100 million cubic meters, including surface water resources1.81.700 million cubic meters, including Xiangjiang river system13.974 billion cubic meters, Zhujiang river system 3.492 billion cubic meters and Ganjiang river system 6.5. The annual recharge of groundwater is 665.438+005 million cubic meters, and the exploitable amount is 2765.438+040 million cubic meters. There are also abundant geothermal water resources in groundwater, with 38 natural springs exposed and 23 million cubic meters of natural water flowing annually.

The characteristics of water resources in Chenzhou city are as follows: first, there is abundant rainfall, but the distribution is uneven. The annual average rainfall is 1504 mm, which is 7 1.3 mm more than that of the whole province and 2.28 times that of the whole country. However, the distribution is uneven during the year, with rainfall of 1783 mm in wet years and 1043 mm in dry years. Uneven distribution during the year, accounting for 64.7% of the annual rainfall from April to September and only 35.3% from June to March. Regional distribution is uneven, and the general trend is decreasing from southeast to northwest. The 1400 mm isohyet divides the city into three parts along the watershed between the Yangtze River Basin and the Pearl River Basin, namely Huangdong, Hankou, Qiaotou and Dida in the southeast of Guangxi, Dongling, Hot Water and Yijiang in Rucheng, Dakuishang, Jiangkou, Yongchun and Furong in Suxian District, and Dongshan and Furong in Linwu. Zixing Xingning passes through Rucheng civilization to Hou Yu and Chukou, and extends to Chishi in Yizhang and the southern half of Jiahe and Guiyang. Anren belongs to the middle area.

Suyuan, Yanquan and 16 1 in Yizhang in the south, and Liu Feng in Guiyang are low-value areas. The average annual rainfall in low-value area is 1230- 1350 mm, that in median area is 1380- 1500 mm, that in high-value area is above 1500 mm, and the highest value is Yiziling rainfall station. The annual total surface water of the whole city is1.81.700 million cubic meters, and the per capita water quantity is 3,980 cubic meters, which is 1.33 times of the per capita water resources of the whole province and 2 1.67 cubic meters of the national per capita water resources. However, water resources change greatly during the year, high and low seasons alternate frequently, and rainfall is concentrated in one year. Moreover, because the terrain in the territory is dominated by hills and hills, the mountains are steep and the river slopes are steep, and the natural reserves of runoff are small, which leads to a large amount of abandoned water in flood season, water shortage in non-flood season, serious water shortage in dry season, more water in wet year and low runoff utilization rate.

Hydraulic resources are relatively abundant. According to the statistics in 2003, the theoretical hydropower reserves of the whole city are 237 1 000 kw, and the exploitable amount is 1 66 1 007 kw, of which the exploitable amount of rural hydropower is 1 057 kw. The city's per capita exploitable capacity is 365 watts, which is 1.88 times of the provincial average 194 watts and 1.2 times of the national average of 303 watts.