Geography of Longchuan county

Groundwater is divided into deep and shallow layers, and deep groundwater is difficult to analyze and calculate because of lack of data. It is found that the shallow groundwater in this county accounts for about 25% of the runoff stations, accounting for 589 million cubic meters.

According to the measurement of relevant departments in 1980, the distribution of groundwater in this county is as follows: the velocity in the lower part of the county is 18 tons/hour, the velocity in the middle part is 7.7 tons to 14.4 tons/hour, and the velocity in the upper part of the county is 12.26 tons/hour.

surface water

There are *** 15 rivers in the county. The main rivers in Hanjiang River are Dongjiang River, Tiechang River and Heshi River.

Dongjiang River system Dongjiang River originates from Yaojibo Mountain in Xunwu County, Jiangxi Province and Dalingzhang in Anyuan County, Jiangxi Province, and is called Xunwu Water and Anyuan Water. The basin area of this county is 2260.4 1 km2, and the flow length is165km. Xunwu water flows through Shang Ping, Mabugang, Yanzhan, Xintian and Chiguang; Anyuan water passes through Dingnan, Jiangxi, and flows through Xi 'ao, Beiling and Mazheng in the county. The two tributaries meet in Fengshuba Reservoir Area, flow through Li Zui, Huangshi, Dongshui (Heping), Sidu, Fengman, Fucheng, Laolong and Tuocheng, and flow into Heyuan County in Hutougang, Shengli Village, Tuocheng.

The average annual runoff of Dongjiang River is 6.2 billion cubic meters, the maximum flood flow is 654.38+0.02 million cubic meters per second, the water level of Laolong River reaches 73.37 meters above sea level, appearing in June 654.38+0.964, and the minimum flood flow is 7.9 cubic meters per second, appearing in June 2, 654.38+0.963.

The rainwater collection area of Dongjiang River in the county 1677 square kilometers. The tributary with a rainwater collection area of over 65,438+000 square kilometers is (1) Xiaojinshui: it originated in Danganzhang, Xunwu County, Jiangxi Province, and the tea activities from it flowed into the capital Tianhe of this county and merged into Xunwu Water. The rainwater collection area of the county is 45. 1 km2, and the flow length is 8.9 km. The average annual runoff is 6.67 cubic meters per second; (2) Living water: It originates from Huang Bei Depression, Shang Ping, and flows into Xunwu Water from Meiliba, with rainwater collection area of 186.5 km2. The length of the river is 3 1.7km, and the average annual runoff is 4.8 cubic meters per second. (3) Shazhou water: It originates from Shangping wild boar's nest and flows into Xunwu water from Chishidu, Mabugang. The rainwater collection area is 1 17 square kilometers. The process is 25.5 kilometers long. The annual average runoff is 7.89 cubic meters per second; (4) Anyuan Water: Also known as Beiling River, it originated in Dalingzhang, Jiangxi Province and flowed into the county seat in xi 'ao. After Beiling and Yanzhan, it meets Xunwu water at the estuary, with a rainwater collection area of 498 square kilometers and a river length of 33 kilometers. The average annual runoff is 58.69 cubic meters per second; (5) Jute water: It originates from Jinshizhang in this county and flows through Xi 'ao and Beiling. Anyuan water flows from Xiqiao, with rainwater collection area of 138.8 square kilometers, flow length of 30 kilometers, and annual runoff of 3.58 cubic meters per second. (6) Chetian Water: originated from Zhang Mao, Thailand. It flows into Fengshuba through the parking lot and Dongjiang at Doubiao. The rainwater collection area is 1.37 square kilometers, the river is 28 kilometers long, and the average annual runoff is 3. 1.4 cubic meters per second. (7) Xiaomiao Water: It originates from Yasha Town, Li Zui, flows into Tanghuang Dongjiang River through Long Mu and Fengman, with rainwater collection area of 173.9 square kilometers and river length of 3 1 km.

There are two rivers running through the south of Fucheng, the Laolong River and Yidu River, and the rainwater collection area is below 100 square kilometers.

Tiechang River in the upper reaches of the Han River belongs to the first-class tributary of the Han River. It originated in Yajizhai, Huilong, passed through Huilong, Tian Xin, Long Mu and Tiechang, left Zhan Lu, and merged into Hechuan River in Wuhua County, with a rainwater collection area of 462.2 square kilometers and a river length of 48.7 kilometers. There are four tributaries: Tian Xin Water, Tian Yang Water, Valley Water and Yangbei River. Jiya originated in Qimuyu, Zishi, flowing through Zishi, Heshi, Tongheng and Deng Yun, flowing into Qiling Town, Wuhua County at Shilaikou, and flowing through the county seat for 35.2 kilometers. Longchuan county is deeply influenced by monsoon climate, which belongs to subtropical monsoon climate, with mild climate, abundant rainfall and sunshine. The average temperature is 2 1.8℃, the average rainfall over the years is1501.8mm, and the average relative humidity is 78%.

The winter is controlled by the polar cold ridge, the northeast monsoon prevails, and the weather is dry and cold; In the summer half year, due to the influence of frontal trough, monsoon depression and tropical cyclone, southwest and southeast monsoon prevail, with high temperature and rainy weather. The annual average temperature of the county station is 265438 0.0℃, the annual rainfall is 65438 0.693mm, the annual sunshine is 65438 0.703.5h, and the frost-free period is 320 days. This subtropical monsoon climate is characterized by mild, abundant rainfall, long summer and short winter, long sunshine time, long frost-free period and obvious monsoon. Agricultural climate is rich in resources, so it is livable and enjoyable. Due to the large span between north and south, diverse topography, obvious seasonal and local differences in climate, agrometeorological disasters occur frequently. Meteorological disasters such as low temperature and rainy weather in spring, dragon boat water in May-June, high temperature in summer, cold dew wind in late autumn, low temperature frost in winter, drought in spring and autumn, local thunderstorm and gale in summer, and heavy rain often bring great harm to industrial and agricultural production in various places.