General situation of Longjiang main stream

In Puning City, the main stream of Longjiang River flows out from the south slope of Nanshui 'ao in Houxi Forest Farm and exits through Radius Field, Houxi and Longtan Reservoir. The main stream of Longjiang River flows through Puning City, with a total length of 26.7 kilometers and a catchment area of 635.6 square kilometers, accounting for about 40% of the whole basin.

In Lufeng City, the main stream of Longjiang River is called Longtan River, also called Guikeng Water, which flows through Shen Du Village of Beiyang Town and enters Lufeng City. The length of the main stream in China is15km, and the drainage area is123km2.

In Huilai County, the main stream of Longjiang River, known as Longxi in history, flows into Kuitan Town of Huilai County through Guikeng in Lufeng City, flows into the main stream of Longjiang River from northwest to southeast through Kuitan Village and barracks in Xikou Village, upstream of Yao Huan Pump Pit, and joins with Nanxi Zaixi, which originates from Huangnitian in Daping Town, Puning County, and Gaopuxi originates from Qingshan 'ao in Daping County, Puning County. The total length is 88 kilometers, and the total water area is 1 164 square kilometers; The county seat is 5 1.3km long and the catchment area is 554.5km2, with an average gradient of 1. 13‰.

Due to the low slope of the lower plain, poor siltation and drainage, and the flash floods in Nanshan Mountain, floods often occur. 1979 completed the downstream river diversion project, excavated a new river with a length of 5 kilometers into the sea, and realized the separation of flood and waterlogging. After diversion, the length of Longjiang River was shortened from 88km to 82km, and the drainage area was changed from 163 1 km2 to 1 187 km2.