Moyangjiang

Moyangjiang

Moyang river is located in the southwest of Guangdong Province,

It originates from Yunwu Mountain range of Yangchun City, flows through Yangchun, Yangdong and Jiangcheng of Yangjiang City, Guangdong Province, and its main tributaries are Yunlin River, Nawu River and Tanshui River.

General situation of main stream

Moyang River, located in the southwest of Guangdong Province, originates from Yunwu Mountain range, Fulin Town, yun'an County, Yunfu City. It runs through Yangchun, Yangdong and Jiangcheng of Yangjiang City. It was injected into the South China Sea at Beijin port in Yangdong district. It lies between 111 ° 16 ′ - 112 ° 22 ′ E and 21 ° 46 ′ - 22 ° 42 ′ n. The total area of the basin is 6091 square kilometers, and the river length is 199 kilometers.

hydrographic features

The annual average measured runoff is 8.21 billion cubic meters, and the annual average total water resources is 8.65 billion cubic meters.

According to the detection of surface water by the environmental protection, water conservancy and health departments of Yangjiang City, the water quality of the rest reaches of Moyangjiang River meets the class III water quality standard of the national surface water environmental quality standard, except for some sections of Yangjiang City and Yangchun City.

There are many mountain passes in the Moyang River Basin, which create good conditions for the formation of rainstorm. The basin is also a place where the cold and warm air flow is still. It is one of the rainstorm centers in South China. The basin is located on the coast of the South China Sea, threatened by typhoons and salty tides. Due to the uneven spatial and temporal distribution of rainfall, drought often occurs in the basin. Among waterlogging, wind and drought, flood is the most serious.

According to historical records: from 1458 to 1949, there were 24 major floods. Among them, in 1516 (the 11th year of mingdezheng), there was a torrential rain. According to the county annals, "the torrential rain lasted for ten days, and the night of Renwu rose sharply. There were thousands of bad public and private houses, and the city collapsed, destroying countless people's fields, and the people lived in poverty when they were not ripe.". In 1620 (the 48th year of the Wanli reign of the Ming Dynasty), the county annals recorded: "in April, there was a flood, a rainstorm and a tide, and the water depth was eight feet. In the area of Huahao and waidanchang of Ximen, more than 700 houses collapsed, and villages such as baishading, mabuyan, and jintoulang were completely submerged.". "The house is completely submerged", that is, the water level has reached above the cornice of the house.

On July 14, 1922, the great flood occurred in Moyang River, commonly known as "Da Liao Wang". The water level in Chuncheng reached 17.02 meters, that in Shuangjie station was 9.2 meters, and that in Yangjiang station was 4.18 meters. There was a vast ocean on both sides of Moyang river. Many houses collapsed, farmland was lost, and there were many beggars after the disaster. At that time, the dike was small and thin, which could only resist ordinary small floods. The floods were all over the floodplain, which subsided quickly and mixed with floods and waterlogging.

After the founding of the people's Republic of China, the largest flood of the Moyang River occurred on October 5-8, 1981. Affected by typhoon, there was a torrential rain in the middle and upper reaches of the Moyang river. The maximum 24-hour rainfall in Guigang was 425.8 mm. According to the actual measurement of Shuangjie hydrological station, the flow was 4390 second cubic meters, and the flood occurred once in 50 years. Except for the port yard, the dike on both sides of the Moyang River collapsed, with 979 gaps and a length of 3 meters 81km, flooded more than 700 villages, collapsed 34000 houses, more than 200000 victims, 47 people died, flooded 38000 hectares of farmland and lost more than 200 million jin of rice.

Main tributaries

Xishan river flows into Moyang River in Heshui Town, with a length of 108 km. It is the branch with the largest drop among the tributaries of Moyang river. Now linwan power station, zhanggonglong reservoir, Dahe Reservoir, Xinlang power station and xishanpi water diversion project have been built, with a total installed capacity of 46700 kW.

Tanshui River, originated in the south of jilongding, Qixingling, Shuangjiao, Yangchun, flows from north to south through Qixing, Puzhu, Guzhong and Dachen, turns to the east by south, passes through Puzhao, Daxin, Huangpo and Qiaolian, and then converges with Qiaolian River, turns to the East through Sanjia Jingshan, Tanshui and Hekou, and flows into Moyang River in Hekou town. With a total length of 107 km and a rainfall collection area of 1421 square kilometers, it is the largest tributary of the Moyang River, accounting for 26% of the water in the whole basin. It is also located between Bajia mountain and Ehuangzhang, the two rainstorm centers. The lack of large-scale water storage projects in the region poses the greatest threat to the flood control of the lower reaches of Moyang River and Yangjiang City. It's named after the pond.

Huangcun River (Yunlin River), originated from gouerdong (mountain), Shiwang Township, Yangchun City, flows from north to south through Jiancun to Shibu River, Tiantang County, Xinxing County, and then into Yangchun. It flows into Moyang river through dagangping, Chunwan and Huangcun of Shiwang, and flows into Liaoshi Weilong village of Chunwan. It is a primary tributary of Moyang River, with a total length of 31.9 km and a rainfall collection area of 288 square km. Located in the northeast of Dongyuan County, it is a primary tributary on the left bank of Dongjiang River, with a river length of 55.8 km and a drainage area of 415 square km.

Nawu River, originated from the north side of Pingdong baihetou, Heshui Town, Yangchun City, flows into Moyang River from east to west by north through Xincun, mulou and xinlongwei. It is a primary tributary of Moyang River, with a total length of 28 kilometers and a drainage area of 123 square kilometers.

Water conservancy development

Before 1949, the water conservancy facilities in the basin were very backward, the dike was low and thin, there was no reservoir, only a small amount of temporary water diversion, flood, waterlogging and drought disasters were frequent, and people's life was not guaranteed. From the founding of the people's Republic of China to the end of the 20th century, more than 5000 wind, flood and drought prevention projects have been built. Among them, there are 2 large reservoirs, namely Dahe Reservoir and Donghu reservoir; 11 medium-sized reservoirs, with a total catchment area of (548) square kilometers and 202 small reservoirs, with a total storage capacity of 1237.2 million cubic meters. The main drainage projects include Moxi drainage project, zhongxinzhou drainage project, Buchang drainage project, manandong drainage project and some small drainage canals and electric drainage stations. 3385 water diversion projects have been built, with the water diversion flow of 92 seconds per meter. Among them, the large and medium-sized water diversion projects include Shuangjie barrage, Hongjiang barrage, xishanpi and xiangshuipi, as well as a number of electric drainage and irrigation stations and culverts Cheng has played a great role in wind prevention, flood control, waterlogging prevention and irrigation.

At the end of the 20th century, there were 149340 hectares of cultivated land (2.2401 million mu) and 72800 hectares of effective irrigation area (1.092 million mu). The population in the basin is 1.9966 million, the GDP is 11973.45 million yuan, the total industrial output value is 12195.71 million yuan, and the total agricultural output value is 5838.99 million yuan. In 2000, the total water consumption was 104578 million cubic meters, including 77 million cubic meters for industry, 854 million cubic meters for agriculture, 50 million cubic meters for urban life and 64 million cubic meters for rural life.

Moyang river flows through Chunwan and joins Yunlin river at Liaoshi Langwei village in Chunwan. Three small reservoirs with a capacity of 6.75 million cubic meters are built on the river, and four small hydropower stations with an installed capacity of more than 100 kW are built, with a total installed capacity of 970 kW. The river basin is downstream and converges with the Nawu river. There is a Naqi reservoir on the river, with a capacity of 3.82 million cubic meters. There are also a number of small water ponds, such as muluopi and shadipi, to irrigate the scattered farmland on both sides of the river. There are also two power stations, such as huangnijia and mashitian, with a total installed capacity of 485 kilowatts.

The river is 108 km long, and it is the branch with the largest drop among the tributaries of Moyang river. Now linwan power station, zhanggonglong reservoir, Dahe Reservoir, Xinlang power station and xishanpi water diversion project have been built, with a total installed capacity of 46700 kW.

The southeast of Moyang river flows through Gangmei town. On the left bank, there is a reservoir, Gangmei reservoir, which is composed of Heshan reservoir and Nama reservoir. It is mainly used for irrigation, flood control and power generation.

To the southeast of Moyang River, it enters Jiangcheng District of Yangjiang City. There is Shuangjie River barrage dam in Shuangjie town. It is a large-scale water conservancy project, 7 km downstream of the entrance of Tanshui River into Moyang river. The dam is 15.5 meters high and 470 meters long. Shuangjie sluice dam and the nearby Shihe reservoir are jointly operated to irrigate more than 80000 mu of farmland in Jiangcheng. The project was started in 1958 and brought into full play in 1963. Shuangjie sluice dam also uses pipelines to supply water to Hailing Island, so as to solve the water shortage in the island.

Basin environment

The terrain of Moyang River Basin inclines from north to south, with mountains on its back and sea on its surface. The upper reaches of the basin are dominated by mountains, narrow valleys, many streams, large gradient and rapid flow; the middle reaches are long and narrow valley basins and small plains, which are typical karst landforms, surrounded by rocks and mountains, with lakes and mountains; the lower reaches are dominated by hills and small plains. There is a great difference in terrain height, and the average gradient of river bed is 0.49 ‰.

Scenery along the Moyang River

The basin geology is composed of granite, sand shale, sandstone, schist and limestone. The mountains in the basin are complete, the soil layer is deep, and the vegetation is good,

Chinese PinYin : Mo Yang Jiang