CATDOLL : CATDOLL: Can I visit Jiuduansha Wetland Nature Reserve?

Jiuduansha is located in the Lanmensha section of the Yangtze River estuary. It is mainly the accumulation of silt, forming three main sandbars, Shangsha, Zhongsha and Xiasha, and the shaded sand of Jiangya Nansha. According to the environmental characteristics and sediment distribution of different areas of Jiuduansha, Jiuduansha sediments include fine sand, silty fine sand, sandy silt, silt and clay silt. The sedimentary silt of Jiuduansha is generally dominated by fine particles. The tidal flat sediments have obvious sedimentary zoning phenomenon, from high tide beach to mid-tidal beach, low tide beach, and subtidal beach. With the increase of hydrodynamic intensity, the particle size of sediments changes from small to large, the clay particle size changes from more to less, and the silt and fine sand particle size changes from less to more. The vertical change of Jiuduansha tidal flat sediments is from top to bottom, from fine to coarse.

Jiuduansha is an estuarine sandbar with an altitude of 2.5~3.5m. According to the height of the terrain, its landforms can be divided into high tide beach, mid-tide beach, low tide beach and underwater shoal. The micro-geomorphology can be divided into a nearly radial low tide drainage system composed of tidal gullies of varying sizes and a swampy shallow depression in the middle of the sandbar, while the beach on the edge of the sandbar has different micro-geomorphology due to the different scouring and silting effects of the rising and falling tides. The reserve is located in the northern subtropical zone. It is affected by the marine climate and the continental climate. The monsoon prevails, it is mild and humid, with abundant rainfall, sufficient sunshine and four distinct seasons. Jiuduansha Wetland is spring from mid-March to early June; summer from mid-June to late September; autumn from early October to mid-November, and winter from late November to March of the following year. Winter and summer are longer, spring and autumn are shorter, northwest winds are more in winter, southeast winds are more in summer, autumn and winter are cold and dry, and spring and summer are warm and rainy.

Temperature

The average annual temperature at Hengsha Station near Jiuduansha is 15.7℃, with the lowest temperature in January (average 4.2℃) and the extreme minimum temperature of -7.7℃. The highest temperature is in July (average 27.3℃) and the extreme maximum temperature of 36.6℃. The frost-free period is 254 days.

illumination

There is sufficient sunlight. The annual sunshine hours at Hengsha Station from 1980 to 1989 were 1798 hours, accounting for 41% of the annual sunshine hours, and the average radiation was 362.7 MJ/m2.

precipitation

The average annual precipitation is about 1145mm. The highest precipitation is in summer, which is 480.2mm. The lowest precipitation is in winter, which is 100.8mm. The average precipitation from April to September is generally greater than 100mm. Although there is snowfall in winter, there is no snow accumulation.

Wind conditions

Jiuduansha is located in the south of the Yangtze River estuary, on the edge of the northern subtropical zone, and belongs to the East Asian monsoon region. The seasonal changes in wind direction are very obvious. Southerly winds prevail in summer, northerly winds prevail in winter, and spring and autumn are transitional seasons. Due to the frequent occurrence of local convective weather in spring and summer, the summer and autumn are often affected by typhoons, and the autumn and winter are often invaded by cold waves and cold air. Therefore, strong winds can occur in the Jiuduansha area in all months of the year. The average wind speed for many years is 3.7~4.0m/s.

From 1960 to 1989, there were 201 tropical cyclones that affected the Yangtze River Estuary and adjacent waters, an average of 3.4 per year. The impact of tropical cyclones was mainly concentrated from July to September. The heavy rains, storm surges and big waves brought by the typhoons caused a strong scouring effect on the shores of Jiuduansha. Due to the seasonal changes in runoff and sediment transport, the periodic changes in tides and tidal currents, the seasonal changes in waves and their randomness, the hydrological elements of Jiuduansha are complex and changeable, showing the unique hydrological characteristics of tidal estuaries.

The hydrology of Jiuduansha is mainly controlled by the Yangtze River current, tides and storm surges. The area near Jiuduansha is an irregular semi-diurnal shallow sea tide, with an average tidal range of 2.67m and a maximum tidal range of 4.62m. The average annual water temperature (Gaoqiao Station) is 17.3℃, with the highest in August, an average of 28.9℃, an extreme maximum of 33.1℃, and the lowest in February, 5.6℃, with an extreme minimum of 2.0℃.

Jiuduansha receives water and sand from the Yangtze River from above and is affected by the sea tide from below, so the hydrodynamic conditions are very complex. The average annual sediment content of the Yangtze River is 0.518kg/m3, and the average annual sediment transported by the sea is 4.86×108 t. In addition to part of the huge amount of sediment entering the sea being deposited at the estuary, providing a rich source of material for the formation of major sand islands, the rest is diffused and deposited outside the estuary under the action of waves and tides. The waves near the Yangtze River estuary are mainly wind waves, and the wave direction frequency is basically consistent with the wind direction frequency, and the seasonal changes are very obvious. According to the vegetation zoning of "Chinese Vegetation", Jiuduansha should belong to the subtropical evergreen and deciduous broad-leaved forest area, the eastern (humid) evergreen broad-leaved forest sub-region, the northern subtropical evergreen and deciduous broad-leaved mixed forest zone, the Jianghuai Plain, cultivated vegetation, and aquatic vegetation zone. The vegetation zonation of Jiuduansha is not obvious, and all of them are hidden regional components.

Jiuduansha Wetland Nature Reserve is bounded by the middle line of the southern dike of the Yangtze River Estuary Deepwater Channel in the north, the -6m line in the east, the northern line of the Yangtze River Nancha Channel in the south, and the -6m line in the west (Jiangya Nanxian Xiasha). The total area of ​​the nature reserve is 423.2km2. It is famous for its rich resources. Jiuduansha Wetland is located at the intersection of the Yangtze River and the East China Sea. It can not only deposit and retain the entrained materials of river water and seawater, effectively absorb nutrients discharged into the East China Sea sewage, and reduce the occurrence of red tides in the East China Sea, but also has a great role in resisting salt water erosion, purifying water quality, and protecting the coastline. It is an important ecological barrier in Shanghai and even the Yangtze River Delta region. The excellent natural conditions of Jiuduansha Wetland provide a superior living and growth environment for a variety of organisms. Reeds, sea thorn grass and other anthill wetland plants are lush. The biomass of benthic animals such as blue crabs, yellow mud snails, and clams is huge. Every year at the turn of winter and spring, a large number of young eels forage and hibernate in the Jiuduansha waters, and Chinese mitten crabs lay eggs and fatten here. Jiuduansha Wetland is also an important stopover and wintering place for migratory birds. There are two national first-class protected birds, the white-headed crane and the relict gull, and 15 national second-class protected birds, such as the black-faced heron and the little swan. It is an important member of the East Asian-Australasian sandpiper bird protection network.

So it's okay, you can play.

I hope you can adopt it.

Yes, Jiuduansha Wetland Reserve is a national wetland nature reserve. It is located in the area of ​​Lanmensha between the north and south channels of the Yangtze River estuary in Shanghai. It is managed by the Jiuduansha Daqin Wetland Nature Reserve Management Bureau. Jiuduansha Municipal Nature Reserve was established in 2000 and was promoted to a national natural limb and branch fracture reserve in 2005. The protected object is the estuarine Xinli closed wetland ecosystem.

Yes, Shanghai Jiuduansha Wetland National Nature Reserve is a very worthwhile attraction. Most people who come to the destination to travel will choose this attraction.

Can you visit the Jiuduansha Wetland Bihuichen Nature Reserve? This is not allowed in Bimeng. If too many people go in, it will damage the environment. In order to protect the wetland environment, tourists are prohibited from entering to play.