"I do," after the male fan heard Tang Lin's words, he turned around and glanced at the female fan behind him very sweetly, and after the surrounding people burst into laughter, he also seemed to suddenly remember something, turned around, looked up at Tang Lin, raised his hands above his head, kept swinging cross, and shouted in his mouth, "No, no, I didn't hear clearly just now, I didn't hear clearly, I want to marry her, not to marry her, not to marry her." ”

When the male fan shouted, he was so anxious that he blushed and blushed, and he didn't know if he was ashamed or what.

"Why, are you so unhappy to marry me? You don't want to marry me, why should I marry you!" When the male fan was still trying to argue for himself, the female fan standing behind him was not happy, and said angrily to the male fan who didn't know that the catastrophe was coming.

"Oh, no, no, no, no, that's not it, my dear, I don't know what I mean, I mean...... I...... Hey, I mean I'm a big man, I should marry you, not you, no, no, no, no, I ...... I...... Hey!" After the male fan heard his girlfriend make such an opinion, he seemed to become a godless person, and when he turned to speak to this female fan, he was at a loss at all, intermittently, and it seemed that he didn't know what he was trying to express.

"What's wrong with marrying me? If you let me marry you, I'm not happy yet!" The female fan said to the male fan unrelentingly, pretending to ignore the anxiety on the male fan's face, the cold sweat that kept breaking out.

"No, no, it's not so, my dear, listen to me, now...... Aren't men generally saying that they marry women? If they are not married, even if they are, that is the term "into the rich", I mean, I am not a woman, if I really want to marry you, then I should also use the word "into the rich, right? I am willing to marry our dear, really, I swear!" When the male fan anxiously defended himself, he seemed to have finally found his focus, and swore to the female fan to explain.

Lugu Lake is an outflow freshwater lake belonging to the Jinsha River system, and the ratio of catchment area to lake area (i.e., lake recharge coefficient) is only 3.82, which is rare among other lakes in China. [9]

The outflow of Lugu Lake reaches 3-5 cubic meters per second during the flood season. After October, the discharge flow is very small, and there is basically no leakage of lake water in January ~ May every year. The lake is a semi-enclosed lake with good runoff conditions, abundant water supply and relatively small water loss. Lugu Lake is a high-source deep-water lake. The maximum water depth is 93.5 meters, and the lake area with a water depth of more than 50 meters accounts for about half of the total lake area, with an average water depth of 40.3 meters, ranking third among China's deep-water lakes, second only to Tianchi Lake and Fuxian Lake. The capacity of the lake reservoir is 2.252 billion cubic meters, surpassing Dianchi Lake and second to Erhai Lake. The maximum transparency of the lake water is 12 meters, the pH value is between 7.7~8.6, the salinity is 0.54 mg/L, and the total hardness of freshwater is 5.5, which is soft water [11]. The water quality of the lake has reached the national surface water class I standard. [9] [2]

The surface water temperature of Hugu Lake is greatly affected by external climatic factors, and the water temperature changes significantly in July and October, and its variation range is 17.1~22.0°C. However, in the deep-water layer (below 40 meters), it is basically constant throughout the year, and it is maintained at 9.5~10 °C. During the year, the surface water temperature in the northern part of Lugu Lake was lower than that in the southern part of the lake. In spring, summer and autumn, there is a phenomenon of thermal stratification in the water body in the northern part of Lugu Lake, especially in summer and autumn, and the water temperature is divided into three layers in the vertical section: the thermostatic layer, the thermocline and the thermocentric. In April, a thermocline appeared in the northern water column at the 25-metre water layer and a thermocline in the southern water column at the 21-metre water layer. In July, the thermocline of the northern and southern water bodies appeared at the 10-meter water layer. In late October, the thermocline of the north and south water bodies appeared at the 20-meter water layer. [12]

Panoramic view of Lugu Lake

Panoramic view of Lugu Lake

Biological Resources Edit

plant

According to historical records and a survey conducted in 2010, there are 784 species of seed plants in the Lugu Lake Basin, belonging to 378 genera and 114 families. Among them there are 11 subspecies, 34 variants, and 4 variants. [13]

(1) Aquatic plants: The abundance of aquatic plants in Lugu Lake is rare among the high-source lakes in China. According to statistics, there are 42 species of aquatic vascular plants, including 3 species of ferns, 14 species of dicots and 25 species of monocots. According to the life type, there are 12 kinds of upright plants, 10 kinds of floating leaves and floating plants, and 20 kinds of submerged plants. [11]

(2) Terrestrial plants: There are 104 families and nearly 650 species of terrestrial seed plants. Among them, there are 18 species of gymnosperms in 5 families and nearly 630 species of angiosperms in 99 families. Due to the abundant natural conditions, there is relatively little human influence, and there are forests from the lakeshore to the surrounding mountains to the highest point at an altitude of 3,870 meters. Among them, Yunnan pine, Lijiang spruce and yellow-backed alpine oak were the most abundant and accounted for the largest area, followed by red birch, Cangshan fir, large-fruited redwood, Huashan pine and poplar, and a small area of native small-fruited weeping cypress. In the shrub layer, there are many rhododendrons, dwarf oaks, hazelnuts, etc., in addition, there are dense arrow bamboos, and the understory grasses include gentian, artemisia, chrysanthemum, scrophularia flowers, butterfly flowers, etc.

According to the literature, there are 42 species of aquatic plants in Lugu Lake, belonging to 23 families and 32 genera, which are divided into 20 species of large aquatic plant communities, among which the water plant community includes 7 community types, including shallot community, Phragmites australis community, cattail community, cocoon grass community, cedar leaf algae community, black triangular community and grass community, and 5 community types of floating-leaf plant community, including Qingping community, eyelid community, Yeling community and Wattle herb community, and the submerged plant community includes sea cauliflower community, spike foxtail community, red thread grass community, bright leaf eyelid community, There were 8 community types, including filamentous green algae community and algae plant community. The upright plant community is mainly distributed on both sides of the estuary with a water depth of 0.3 ~ 1 m or in the depression of the bay, shallow and swamp, and the bottom is generally thick silt; the floating leaf plant community is very underdeveloped in Lugu Lake, and is only sporadically distributed in the local waters of the bay or lake area; the submerged plant community is mainly distributed in the water area near the bay and the village with a water depth of 1~10 meters, and the deepest distribution is the Rotula and Liphys. The submerged plant community is very developed in Lugu Lake, which not only has many species and large biomass, but also has a much wider distribution width than the floating water and upright water community types, which occupies an absolute advantage. [14] [15-18]

The survey results in July 2013 and April 2014 showed that there were 39 species of macrophytes belonging to 24 families, including 2 species of ferns, accounting for 5.3% of the total species, 29 species of monocots, accounting for 74.4%, 7 species of dicots, accounting for 18.9%, and algae (including Algae and Licosa). According to the life form of aquatic plants, there were 13 species of upright plants, accounting for 33.3%, belonging to 7 families of Poaceae and Cyperaceae, 2 species of floating plants, accounting for 5.1%, belonging to Duckweed and Manjiangaceae, 6 species of floating-leaved plants, accounting for 15.4%, belonging to 6 families of Gentian and Ichthaceae, and 18 species of submerged plants, accounting for 46.2%, belonging to 9 families, including Rodaceae, Ichthaceae, Phycophyceae and Turtle Family. [14]

The macrophytes of Lugu Lake are distributed in a ring along the shore zone, with an area of about 824.47 hectares, accounting for 14.7% of the total area of the lake, and the distribution area of macrophytes is about 263.26 hectares, accounting for 4.7% of the total area of the lake. From the perspective of the three types of plant communities, the distribution area of submerged plants accounted for 96.1%, the distribution area of floating leaves and floating plants accounted for 2.7%, and the distribution area of upright plants accounted for 1.2%. [14]

animal

The hydrosphere of Lugu Lake is a semi-enclosed ecological environment with a variety of animal species. There are 12 species of fish in 3 orders, 4 families, 4 of which are native to Lugu Lake: Schizophrenia thicklip, Schizophrenia ninglang, Schizophrenia lugu Lake, and Loach, 3 endemic species: Schizophrenia thick-lipped fish, Schizophrenia nipple, and Schizophrenia small-mouthed Schizophrenus, and the other 8 species are secondary carp, grass carp, wheat ear fish, whitebait, crucian carp, etc. [19]. As for the fish problem in Lugu Lake, as far as schizophrenia is concerned, in the past, there were still six or seven species of schizophrenia, such as "white striped fish", "white smashing mouth", "thick largemouth fish", "thin largemouth fish", "snake fish", "herring fish", and "grass-eating fine scale fish". [9] The economic value of the three species of schizophrenia is higher [20], but the annual production has declined sharply, from 300 tons in the 50s of the 20th century, to 30 tons in the 80s, and to about 2 tons in the 90s [21]. There are 15 species of fish in Lugu Lake, belonging to 5 orders and 6 families, 8 species of fish species in Lugu Lake in 2004, and 11 species of fish species in Lugu Lake in 2014. Due to the gradual entry of 11 alien fish species into Lugu Lake, the fish fauna of the lake has been controlled by alien species, and three endemic schizophrenia species are on the verge of commercial extinction. The characteristics of the fish fauna of Lugu Lake are as follows: poor species, small individuals, and slightly slower growth, which are also the common characteristics of lakes in the Yunnan-Guizhou Plateau. The natural environment of the Lugu Lake basin is suitable, the water volume is abundant, the water quality is excellent, and there are certain favorable conditions for the development of fisheries. The fish fauna of Lugu Lake is characterized by a lack of species, small individuals, and slightly slower growth. It is these characteristics that determine the low performance of the lake's fishery products, and basically the annual fish output of Lugu Lake is about 100 tons. The analysis of the biology of the main fish in Lugu Lake shows that in addition to the inherent attributes of the fish, the reason for the low yield is not only the inherent attributes of the fish itself, but also the incompatibility of the type and quantity of fish bait organisms and their reproduction ability. [6]

Water System CompositionEdit

Upstream water system

There are 18 rivers entering Lugu Lake (11 in Yunnan and 7 in Sichuan), of which 9 are Changliu rivers (5 in Yunnan and 4 in Sichuan), namely Dayuba River, Wuma River, Yougu River, Wangjiawan River, Langfang River, Cave River, Mengda River, Dazui River and Bada River. The mountain springs that flow into the lake mainly include the mountain stream near Sanjia Village, the small fish dam mountain stream, and the big fish dam mountain stream near Luoshui Administrative Village. Lugu Lake, the mountain springs flowing into the lake mainly include the mountain stream near Sanjia Village, the small fish dam mountain stream, and the big fish dam mountain stream near Luoshui Administrative Village. In addition to the above-mentioned springs, the lake is fed mainly by rainwater. The precipitation in the Lugu Lake basin is slightly higher than that in the outer areas of the lake basin, with an average annual precipitation of about 1,000 mm. Among them, 89% of the annual precipitation is concentrated in 6~10 months. Because the catchment area of Lugu Lake is not large, the channels into the lake are very short, and the larger ones are the Shanguo River that flows in from the east bank and the Sanjiacun River that flows in from the south bank. Temporary gully stream catchments and inter-slope overflow are the main forms of lake water recharge. [9] [6]

In addition to rainfall and Sichuan spring water, the recharge of lake water mainly lies in the groundwater of Lugu Lake itself. Luyuan Cliff is the location of the outlet of the groundwater of Lugu Lake. [22]

The outlet of Lugu Lake is on the east bank, in June ~ October every year, the lake water is poured into the Qiansuo River through the Dacaohai on the east side, and then into the Gaizu River (called the Yongning River in the downstream), and then into the Wolong River (also known as the Woluo River and Yanyuan River), and then into the Litang River, and finally into the Yalong River, a tributary of the Jinsha River in the upper reaches of the Yangtze River. [9]

Lugu Lake is a land and sea water cycle, belonging to the Jinsha River system in the upper reaches of the Yangtze River, and its path is: precipitation (surface and underground runoff) ≥ Lugu Lake≥ lake water outlet (Caohai located in the southeast of the lake), ≥ Gaizu River≥ Yalong River≥ Jinsha River≥ Yangtze River≥ East China Sea (Pacific Ocean). The flood season of Lugu Lake is concentrated from June to October every year, and only during the flood season will the lake water be discharged from the surface channel, and the flow of the drainage channel at other times is very small or even non-existent. In addition to the surface river effluent, the dissolution fault structure of Lugu Lake will also cause the lake water to flow outward from the karst cave on the inner wall of the lake basin.

Wolong River, also known as Woluo River, Yanyuan River, is the largest tributary of Litang River, originates from Donghou Longshan, Weicheng Town, Yanyuan County, passes through the Yanyuan Basin from east to west, turns north to the wheat field of Muli County, enters the Litang River, the river is 167 kilometers long, the basin area is 8482 square kilometers, accounting for about 44% of the area of the Litang River Basin, the drop is 1632 meters, the theoretical reserves of the main stream water energy are 390,000 kilowatts, and the possible development capacity is 300,000 kilowatts. Ninglang River, etc. [23]

Litang River, an immeasurable river, is also known as Lequ and Muli River. The river originates from the Shaluli Mountain System of Litang County Xia Sai Snow Mountain Pass (5838 meters above sea level), flows from northwest to southeast through Xiao, Da Maoya Dam, after passing Litang County, the river channel makes an "S" shaped bend, turns southeast through Maosang to Mulaxi and flows into the high mountain valley, turns sharply to the southeast through Muli County, has the Wolong River on the right bank to join, the river suddenly turns to the northeast, and flows into the Yalong River in the opposite direction in the south of Wali. The section of the Litang River in Litang County is called Lequ, and the section of the river in Muli County is also called the Muli River and the Xiaojin River. There are hydrological stations in Litang County and Xiagu in Muli County. The Litang River is 516 kilometers long, with a drop of 3,050 meters, a basin area of 19,114 square kilometers, an estuarine flow of about 268 meters per second, and a hydropower reserve of 2.222 million kilowatts. The potential development capacity is 645,000 kilowatts. The middle and upper sections of the river are located in the vast and open plateau with an average altitude of more than 3,500 meters, the river channel is tortuous, the cutting is very shallow, the swamp is developed, the lakes are grouped, and the aquatic plants are luxuriant; [23]