Hongjiannao Lake

Hongjiannao is the largest desert freshwater lake in China. "Nao" is a Mongolian language with the meaning of water and lake. It is also called "Zhaojun's tears". There is a story about Wang Zhaojun's marriage to Xiongnu. It has vast expanses and beautiful water and grass. It not only has grassland scenery, but also has the scenery of Zeguo in the south of the Yangtze River Project. From March to April every year, gulls from afar breed and inhabit here, and they will not move out until early August to September. Therefore, it is also the most special beauty of Hongjiannao to watch these "wetland elves".

Hongjiannao Lake

Hongjiannao, also known as hongjiannaoer and Hongjiannaohaizi, is a boundary Lake in Shaanxi and Inner Mongolia. It is located between Shenmu county of Shaanxi Province and Yijinhuoluo banner of Inner Mongolia Autonomous Region, in the transition zone between Loess Plateau and Inner Mongolia Plateau, and at the intersection of Maowusu Desert and Ordos Basin. With a total area of 54 square kilometers, Hongjiannao lake is the largest desert Lake in China.

Hongjiannao is a young lake formed by gradually accumulating water since Qing Dynasty. At the beginning of the 21st century, tourism development and ecological problems are concerned and known by people. At the same time, Hongjiannao is the main local fishing ground, and the lake water can also provide water for the development of coal fields in Northern Shaanxi, so it plays an important role in the economic development of Northern Shaanxi.

Location context

The naming of Hongjiannao is related to Mongolian. "Nao" is the abbreviation of "Naoer (Lake)" in Mongolian. The sand on the lake bank and shoal is light red (salt color). The lake water is salty water and contains alkali, so it is called "Hongjiannao" in Chinese.

Hongjiannao is a lake shared by Inner Mongolia Autonomous Region and Shaanxi Province. It is located in the northeast corner of erlinhu town in the northwest of Shenmu county, Shaanxi Province, at the junction of Zhongji Township and Zhasake town in the east of Yijinhuoluo banner, Inner Mongolia Autonomous Region, with a total length of 32 km. In the 1980s, the total area of the Lake reached 54 square kilometers, the perimeter of the lake bank was 50 kilometers, the water surface reached 100000 mu, the water storage capacity reached 700 million cubic meters, the maximum depth was 15 meters, and the average water depth was 4 meters, becoming the largest inland lake in Shaanxi Province. It looks like a triangle. Due to the decrease of water source and evaporation, the water surface tends to shrink. According to the monitoring of Shaanxi Agricultural Remote Sensing Information Center, the area of Hongjiannao was 57 square kilometers in 1997, and only 31.51 square kilometers in 2015, a decrease of 44.7%.

The water surface elevation of Hongjiannao is 1222 meters, the average water depth is 15-16 meters, the maximum depth is 20 meters, and the total water volume is 810 million cubic meters. It is the largest lake in Shaanxi Province.

Formation process

In the early Late Pleistocene, Hongjiannao was still a normal valley basin in the upper reaches of Tuwei River in Shenmu. The surface water and groundwater from the upper reaches of the basin flowed southeast through gongbohaizi (located in Yao Town, Shenmu county). However, in the late Pleistocene, the sand deposits moved eastward along the northern foot of Mudu tuliang (in Erlin tuliang), gradually blocking the ancient river channel in Gongpo Haizi area. With the continuous accumulation of sand, the low-lying valley was buried, and the ground was gradually raised to the same level with the northern foot of Lianggang in the west, forming a surface watershed. But at this time, Hongjiannao area has not yet formed a lake, which is a swamp wetland.

During the reign of Daoguang in the Qing Dynasty, it was still a marshland with little water. Once there was a severe drought, the lake dried up. In the 17 years of the Republic of China, the lake could be crossed by horse. During the Tongzhi period, it was assigned to Shenmu county. Later, the amount of water gradually became a lake.

It is also recorded that in the 1920s, the lake site was still a lush natural pasture, with a main road running through the north and south, which was an important channel for the people of Mongolia and Han. After more than a year of ponding, it became a pool and was renamed Hongjiannao. Before 1929, there was about 2000 mu of water surface. From 1929 to 1947, due to the continuous precipitation and the low-lying land, there were more than 30000 mu of lake surface. After the founding of the people's Republic of China, the local people vigorously carried out water conservancy construction, opened ditches for drainage and concentrated water injection. In addition, there were seven seasonal inland rivers around, such as mudushili River, haolai River, qigesu River, Yingpan River, Tuo River, manggaitu River and Erlin river As a result, the accumulated water in the lake increased rapidly and the lake became wider. In 1954, the river network was greatly developed, and the common people dug canals to draw water. By 1958, it had reached more than 60000 mu, engulfed more than 6000 mu of farmland, and forced 350 households to move. In the 1960s, Hongjiannao was flooded year after year. In 1969, the area of Hongjiannao rose to 105000 mu, which is the largest water area in Hongjiannao history. In the 1980s, the total area of the Lake reached 54 square kilometers, the perimeter of the lake bank was 50 kilometers, the water surface reached 100000 mu, the water storage capacity reached 700 million cubic meters, the maximum depth was 15 meters, and the average water depth was 4 meters, becoming the largest inland lake in Shaanxi Province.

Main tributaries

Hongjiannao is located in the southern edge of Maowusu Desert. It is a lake shared by Inner Mongolia Autonomous Region and Shaanxi Province. The total drainage area of Hongjiannao is 1500 square kilometers, and the drainage area in Inner Mongolia is 748 square kilometers. Hongjiannao is formed by accumulated water in desert depression. It is recharged by 12 regular water and seasonal rivers. These rivers are small inland rivers with short rivers and poor supply conditions, all of which are seasonal rivers. The total annual runoff is 56.19 million cubic meters, and there are five rivers entering the lake in Inner Mongolia.

The larger ones are zasak River (Yingpan River), dushili River, manggai River, haolai River, qigaisu River (also known as qigelu River), erlinu River, qianmiao River, Tuohe River, etc.

Zhasake River (Yingpan River) originates from linjiatandu, Hongqinghe Township, Yijinhuoluo banner, flows through Xinjie Town, Yijinhuoluo banner, and then enters Hongjiannao. The main channel is 31.5 km long. The average River gradient is 6.6 ‰, the drainage area is 312.7 square kilometers, and the average annual runoff is 7.36 million cubic meters. The base flow is 2.1 million cubic meters.

Ganzhanmiao River (gaolemiao River and manggaitu River) originates from the north side of taigesumtailuo temple in Yijinhuoluo banner, flows southeast to the junction of Wushen Banner, turns East, and then enters Hongjiannao. The main channel is 23 km long with an average gradient of 4.9 ‰. The basin covers an area of 288.7 square kilometers, with an average annual runoff of 5.53 million cubic meters. The base flow is 1.23 million cubic meters.

Qibusu River, located in erlinu Town, Shenmu county, originates from shibantaiba xiacaidang village, flows into yuanjiagedu River downstream, flows through zucchini, qianhulusin and houerlinu, and flows into Hongjiannaohaizi, with a total length of 22 km, involving six villager groups.

hydrographic features

According to the measurement, the amount of precipitation is closely related to the rise and fall of the water level of the lake. If the annual precipitation exceeds 500mm, the water level of the lake will rise 400-500mm. On the contrary, it decreases. If the water level rises too high, it can flow into Tuwei River and flow out.

According to the determination of Shaanxi Fisheries Research Institute, the salt content of the water is 2.45%, and the hydrogen ion concentration (PH) rises to 9 during the day and drops to 3.2 at night. The area is stable in the shallow water area with 8.5 to 8.8 aquatic plants.

Due to the filtration effect of desert, the lake water is clear to the bottom with low alkalinity and no bitter taste.

The data show that the pH value of Hongjiannao was about 7 in the 1960s, 7.2 in the 1980s, and 8.2 in the 1990s. In 2010, due to the shrinking area of Hongjiannao, the salt content of the lake water increased, and the pH value reached 9.6. This number is far beyond the limit of fish survival.

Hongjiannao is the collection center of regional surface water and groundwater. The average annual evaporation intensity in the area is 1788.4mm, and the annual evaporation amount from Hongjiannao is 0.93 × 108m3. Although the supplied water is low mineralized water with simple water quality, under the strong evaporation and concentration effect, salt gradually accumulated in the long geological history period, and the water quality of the lake gradually deteriorated.

From the 1970s to the early 1990s, the water quantity and evaporation of Hongjiannao Lake were basically balanced, and the water level changed little. From the end of 1990s to 2002, the water level of Hongjiannao Lake dropped by about 10-15 cm every year. After 2002, the water level dropped faster, about 20-30 cm every year, sometimes up to 40 cm. The water level dropped faster.

The drainage area of Yingpan River in Inner Mongolia accounts for more than one-third of the drainage area of Hongjiannao. However, in 2006, a dam was built on Yingpan River to completely intercept the river. In 2012, an underground reservoir was built on manggaitu River, which directly affected the water supply of Hongjiannao.

A monitoring section in the center of Hongjiannao lake is set. According to the monitoring of Yulin Environmental Protection Bureau, in the first half of 2017, the water quality of Hongjiannao lake was inferior to class v. the concentrations of permanganate index, chemical oxygen demand, total nitrogen, total phosphorus and fluoride exceeded the standard by 1.12 times, 0.5 times, 2.66 times, 0.73 times and 5.34 times, respectively. The water was seriously polluted.

natural resources

The main biological resources are aquatic organisms. The water quality of Hongjiannao is slightly salty and suitable for fish growth.

There are 12 kinds of aquatic products in the lake, including carp, crucian carp, silver carp, grass carp, flat fish, culter, wheatfish, meal fish, fish, loach, loach, etc. among

Chinese PinYin : Hong Jian Nao