Hainan Island, separated from the northQiongzhou StraitAnd Guangdong ProvinceLeizhou PeninsulaFacing each other, separated to the westBeibu GulfIt faces Qinzhou City, Guangxi Zhuang Autonomous Region, China and Vietnam.The land surface is pear shaped oval, with the long axis running from northeast to southwest, covering an area of more than 30000 square kilometers, and it is the second largest island in China.
The tropical rainforest on the island is dense, and the sea water is clear and blue. There are two seasons in a year: dry season and rainy season.Hainan Island is low and flat around and high in the middle, with a dome shaped mountain terrainWuzhi Mountain、Yingge RidgeIt is the core of uplift, and gradually descends outward. It is a circular layered landform composed of mountains, hills, platforms and plains, with obvious step structure.[1]
The coastline of Hainan Island is curved, with a length of about 1618 km (the new data is 1823). There are 68 harbors available along the coast, of which the alternative harbors for deep-water ports are relatively scattered.CompletedHaikou Port、Sanya Port、Yangpu Port、Basuo PortandQinglan PortAnd other five major ports.[2]
Hainan Island is known by biologists as the natural "species gene pool" and the largest "nature museum".It is known as the "Kingdom of Southern Medicine";Hainan's wild species, such as wild rice, small grain rice, wild litchi, wild tea, and red shell pine, are invaluable in scientific research and production.102 kinds of rare animals, including black crested gibbon and Hainan slope deer, are listed in the national first and second class key protected animals list.[3]
The magnificent mountains and rivers, mysterious primitive forests, rare tropical animals and plants, beautiful coconut wind and sea charm and other natural landscapes on Hainan Island;Li and Miao folk customs, precious revolutionary memorial sites and cultural relics and other cultural landscapes;With pleasant climate, it forms rich tourism resources.[3]
According to ancient records, Hainan Island and the South China Sea Islands had already belonged to the Central Plains Dynasty in the pre Qin period.Since Qin Dynasty, it has been under the jurisdiction of Xiangjun, Nanyue, Zhuya, Dan'er, Huguang, Guangxi, Guangdong and Hainan provinces. In 1988, Hainan Province was founded and Hainan Island belonged to.Hainan is the only one in ChinaLi nationalityResidential areas.[3]
Hainan Island, located in ChinaSouth China SeaNorthwest, northwest of Hainan Province, 18 ° 10 '~20 ° 10' N, 108 ° 37 '~111 ° 03' E, north of GuangdongLeizhou PeninsulaSeparatedQiongzhou StraitIt is about 18 nautical miles wide, about 220 nautical miles from Haikou City in the north of the island to Haiphong City in Vietnam, and about 650 nautical miles from Sanya Port in the south of the island to Manila Port in the Philippines.
The outline of the island is like an oval Sydney, with the long axis from northeast to southwest, about 290 kilometers long[1], about 180 kilometers wide from northwest to southeast[1](Others are 240 km long and 210 km wide[5]）With an area of 33900 square kilometers[1][6](Others say 34400 square kilometers[5]）It is the second largest island in China after Taiwan Island.The total length of coastline is 1944km (excluding island coastline), and the natural coastline is 1272.61km,[1][6](1618 km[2]1823km[4]）There are 68 harbors and bays, and 2330.55 square kilometers of contour areas ranging from minus 5 meters to minus 10 meters around, equivalent to 6.8% of the land area.[6]
Geological characteristics
Announce
edit
Formation and change
In the Early Paleozoic (570 million years ago to 440 million years ago), the Leizhou Peninsula and Hainan Island area wereSubsidence zone。Caledonian orogeny made Leiqiong area rise to become land, forming a series of fault fold belts mainly in the northeast, which made the strata deposited in the Early Paleozoic changed qualitatively.The Hainan Island landmass was relatively stable in the Late Paleozoic (440 million to 230 million years ago).butIndosinian movementIt also promotes the intense magmatic activity, forming the widely distributed granite body in Hainan Island, forming the mountains and the foundation of Hainan Island.LaterYanshan movementandHimalayan MovementIt also caused a strong fracture of the granite dome, forming several large east-west fault zones, lifting about two-thirds of the area to the south of the fault, called Hainan tectonic uplift, which has been rising for more than 100 million years;Subsidence occurs to the north of the fault, which is called Leiqiong Sag.However, before the Quaternary period (2.5 million years ago), Hainan Island and Leizhou Peninsula were still connected together, belonging to the extension of the Cathaysia block in geological structure.In the mid Pleistocene (2.5 million years ago to 15000 years ago), due to volcanic activity, a fault depression occurred between Leizhou Peninsula and Hainan IslandQiongzhou StraitHainan Island was separated from the mainland.Since then, the sea level has been rising and falling for many times, and Hainan Island has been separated and connected with the mainland for many timesQuaternary glaciationAt the end, the sea level rose significantly, forming the Qiongzhou Strait and Hainan Island.
Hainan tectonic uplift caused by geological tectonic movement is the continuous uplift of the central part of Hainan Island, which gradually forms the geomorphic characteristics of Hainan Island;Mountainous areas are located in the center, with hills, platforms and plains surrounding in turn.The average altitude of Hainan Island is 120 meters.Mountainous areas over 500 meters account for 25% of the island, and plains and platforms over 100 meters account for two-thirds.[7]
Some scholars also believe that Hainan Island began to separate from the Beibu Gulf of China 24 million years ago, and it rotated about 150 degrees counterclockwise from its original position to reach its current position, still drifting left to southeast.[8]
geological structure
In terms of spatial distribution, the geological structure of Hainan Island forms the main structural systems of east-west structure, south-north structure, northeast structure, northwest structure and other structures with different directions, features and properties, which become the main structural pattern of the land and control the island land sedimentary formation, magmatic activity, mineralization and the distribution of mountains and rivers in recent times.[9]
The deep geological structure of Hainan Island is shown as a depression on the background of mantle uplift. The center of the mantle depression is in the Qiongzhong Ledong area, and the depth of the mantle depression is more than 30 kilometers.Due to the difference of crustal structure and deep structure in the island, there are many different characteristics in geological structure, sedimentary formation and magmatic activity.[9]
Hainan Island is low and flat around and high in the middle. It is a dome shaped mountain terrain, with Wuzhi Mountain and Yingge Ridge as the core of the bulge, and gradually descends outward. The mountain, hill, platform, and plain form a circular layered landform, with an obvious cascade structure.
Hainan Island is dominated by mountains and hills, accounting for 38.7% of the island area.The mountains are mainly distributed in the south of the central part of the island, and hilly basins are scattered in the mountains.The hills are mainly distributed in the interior, northwest and southwest of the island.Around mountains and hills, platforms and terraces with different widths are widely distributed, accounting for 49.5% of the total area of the island.Most of the roundabouts are coastal plains, accounting for 11.2% of the total area of the island.The coast is mainly the sea erosion accumulation coast of volcanic basalt platform, the small harbor or accumulation landform coast evolved from drowned valley, and the sea accumulation terrace coast surrounded by sand dike.Coastal ecology is characterized by tropical mangrove coast and coral reef coast.[1]
a mountain country
Wuzhi Mountain
The mountainous area of Hainan Island is located in the south of the central part of the island, bounded by Guangya, Danzhou, Renxing, Tunchang, Wupo and Longtang in the north, Changmao, Tiandu, Baoting and Guangpo in the south, Dongsheng, Juntian and Xinglong in the east, Changjiang, Datian and Jianfeng in the west, covering an area of 8639 square kilometers, accounting for 25.1% of the island area.The mountains in the middle are more than 500 meters above sea level, which are the skeleton of Hainan's landform, mainly Zhongshan (more than 800 meters), with an area of 6067.6 square kilometers, accounting for more than 70% of the mountains;Low mountains (500~800 meters) are only 2571.4 square kilometers, accounting for nearly 30%.The mountain is mainly composed of granite, which is high and round.The mountains are generally divided into three columns, all in the northeast southwest direction: in the eastWuzhi Mountain RangeThe main peaks are Zima Mountain, Wuzhi Mountain, Diaoluo Mountain, Qizhi Mountain, Mazui Mountain, etc;Column in isLimu RidgeMountains, the main peaks are Limu Ridge, Yingge Ridge, Houmacao Ridge, Jianfeng Ridge, etc;In the west is the Yakaling Mountains, the main peaks areYakalingBawang Ridge, Xianpo Ridge, etc.[11]
Hilly basin
Tunchang County at the northern foot of Wuzhi Mountain
Hainan's hilly belt around mountains is not large, accounting for only 13.1% of the area of Hainan Island.There are also high level or gentle mountaintop surfaces in the hilly land, and the common ones are 450 meters, 350 meters and 250 meters.Basins between hills, such as Baisha Basin, Tunchang Basin, Ledong Basin and Qionghai Shibi Basin, have superior light, heat, water, soil and various ecological conditions, which are good environments for the growth of crops and economic trees.The low hills, valleys and basins below 350 meters above sea level have sufficient rainfall and river water moisture, good soil quality and wind proof conditions, which are very suitable for the development of natural rubber and tropical cash crops. Therefore, the hilly belt around the mountains has become the distribution belt of rubber hot farming in Hainan and the largest rubber hot farming base in China.[11]
Platform terrace
The platform of Hainan Island accounts for the largest proportion of various landforms, accounting for about one-third of the total area of the island.Broad platforms are mainly distributed in the northern part of Hainan, which can be divided into two levels: 20 meters above sea level and 40~50 meters above sea level, and gradually incline to the sea.[11]
The platform landform types are diversified, including basalt platform, granite platform, red rock platform and metamorphic rock platform, of which basalt platform has the largest area of 4159 square kilometers, accounting for nearly 40% of the total platform area.On the basalt platform, there are typical volcanic lava landforms, which are due to the frequent volcanic activities in Leiqiong area during the neotectonic movement period from late Tertiary to Quaternary in the Cenozoic in the geological history, and large-scale magmatic eruption lava flows along the fault zone for many times, forming groups of ancient volcanic cones and large areas of basalt in the north of Hainan Island.There are 101 volcanic cones and more than 110 eruptive vents. The most typical ones are Shishan Mountain in the west of Qiongshan Mountain and dozens of volcanic vents and flowing rocks in Yongxing area.Basalt platform is a low flat platform formed by the flow and layering of volcanic lava on the surface, commonly known as "stone ground". For example, Qiongyangshan area, Danzhou Mutang, Ding'an Longtang and other places have large areas of this landform, with small soil thickness but fertile soil.Lava landform also forms lava tunnels. For example, 11 tunnels such as "Immortal Cave" and "Wolong Cave" have been found in Qiongshan Shishan area, which are generally more than 10 meters wide, 2~4 meters high, and the longest is more than 1200 meters long, with a total length of 3574 meters, becoming a local natural wonder.There are also many platforms formed by sea erosion, such as the granite egg landform under Shimen Ridge in the northeast of Jiusuo, Ledong Li Autonomous County, which retains obvious sea erosion terrain, such as fungus shaped stones, stone pillars, stone sticks, stone pots, honeycomb shaped sea caves, frontal cliffs, etc.[11]
Coastal plain
The coastal plain belt of Hainan Island is the outermost ring of the geomorphic ring structure of Hainan Island, with an area of more than 7800 square kilometersCoastal plain, lagoon plainDelta plainIt is composed of three landforms.[11]
The coastal plain is composed of several sandbanks and dry low-lying lagoon swamps. The terrain is undulating, and the sandbanks are high, sandy soil, and drought tolerant plants grow;The lower part is grayish black marshland with sticky soil.For example, in the Yinggehai area of Ledong, a south-north sandbank group is formed on the west bank, while an east-west sandbank group is formed on the south bank, which makes the Yinggehai sandbank group composed of two groups of sandbanks with different directions and protrude into the sea as a triangular headland, and the sandbank becomes a lagoon depression.[11]
The lagoon plain is behind the coastal sandbank, and the east coast is the most typical coastal areas such as Wenchang, Qionghai and Wanning.Wanning Xiaohai, the largest lagoon in Hainan, is a typical lagoon because the bay is separated by a large sandbank, but it has not dried up into a depression.Other lagoon areas are mostly filled and dried by wind blown sand to form a plain. The surface layer is sandy soil layer, and the lower layer is clay layer, black lagoon clay layer, and some peat soil.[11]
Haikou City on the Nandu Jiangkou Delta
The delta plain is formed by sediment accumulation at the river outlet, but Hainan Island is densely forested, the river sediment concentration is not large, and most river outlet sediments are not stacked thickly. For example, the estuaries of Changhua River, Wanquan River, Lingshui River, etc. only stay in the embryonic form of the delta or estuary plain state, and the typical delta is the Nandu Jiangkou Delta located in Haikou City,There is also the Beimen River Delta near the Beibu Gulf in the northwest of Danzhou.[11]
The Nandu River Delta is the largest delta in Hainan. It is formed by the ancient drowned valley bay at the mouth of the Nandu River, which has deposited marine and river sediments such as fine sand and mud containing shellfish for tens of millions of years.[11]
coast
The total coastline of Hainan Province is 1927.6 kilometers, of which the coastline of Hainan Island is about 1618 kilometers long,[2](The new data is 1823[4]）The coastline coefficient is 0.0477.[12]
The tropical coastal landforms of Hainan Island mainly include sand bank accumulation, beach rock, mangrove coast, coral reef coast and harbor landforms.
Red sand embankment accumulationHainan is located in the tropics. The iron in the coastal sand beach and sand dike is fully oxidized, which makes the sand dike become a reddish deposit (belonging to the late Pleistocene).For example, the red sand embankment between Tanghu Lake in Lingshui New Village and Li'an Port extends down from the foot of Phoenix Mountain, covering the white sand beach, and cemented into hard red sandstone.The coast from Ledong Jiusuo to Changhua of Changjiang River and the coast of Wenchang all have this red sand embankment landform.On the northeast coast of Hainan, which is facing the northeast monsoon, from Mulantou in Wenchang to Baohu Port, the coastal aeolian sand accumulates higher and higher, and the aeolian sand dunes are developed. The sand embankment is more than 30 kilometers long, and the highest point, Changsa Lake Pond Slope, is more than 58 meters long, which is rare in the country.[13]
Beach rock on the beachOn the beach, from the beach surface to the sea surface, due to strong sunlight, calcareous saturated precipitation in the water cemented the sand into a layer of hard coarse sandstone and conglomerate, the thickness is generally less than 2 meters.This kind of calcareous cemented sand layer is called beach rock. The rock stratum inclines to the sea and forms rock piles or huge reef blocks after being broken by wind and waves. It is a good place for abalone to live.If the coast is eroded and retreated, the beach rock stratum can be preserved in the shallow water off the coast, such as the reef two or three hundred meters away from the Yingge coast in Ledong County.[13]
Mangrove Coast of Qinglan Port
Tropical mangrove forest seaThe mangrove coast is a special tropical biological coastal landform, which is distributed on the mudflat in the calm wind environment in the harbor. The beach with strong wind and waves cannot grow mangroves.The relatively developed mangrove coasts are mainly distributed in Zhai Port in Qiongshan, the interior of Puqian Port and Qinglan Port in Wenchang, the north and south of Fengjia Port, Lingao Xinying Port, Danzhou Xinying Port and Chengmai Maliao Port.In addition, small areas are also distributed in Haikou, Qionghai, Sanya, Lingshui and other cities and counties.Hainan has many kinds of mangroves, tall trees, fast growth, and the number and area are the highest in the country, known as "marine forest" and "coast guard".[13]
Atoll reef coastThe coral reef is formed by the long-term accumulation of the skeleton of tropical shallow water reef building corals and other calcareous remains, which is also a typical tropical biological coastal landform.Corals generally grow in shallow waters with transparent, mud free and wavy water, and can form a reef (platform) terrain on the coast. In fact, they are a huge group of calcareous organisms. In the long-term continuous growth process, they form a special coral reef coastal type, with a thickness of less than 10 meters. Below them are sand and mud layers or bedrock, belonging to Holocene transgressive facies.Coral reef has the function of protecting the coast from wave erosion, and it is also the place where fish and aquatic products are concentrated. Therefore, the productivity of reef area is larger than that of estuary area, with an average of 4000 grams/square meters per year.There are more than 110 species of shallow water reef building corals in Hainan Island, and the coastal environment of the atoll is very suitable for their growth. Therefore, coral reefs are particularly developed, with a growth zone of up to 2000 meters wide, ranking first in China.[13]
Boao, the beach
Sandy coast,It is mainly distributed along the sandbar lagoon and the delta plain.In the section from Baohujiao to Dahuajiao, the sandy coast accounts for the majority, and the section of about 250km is the sandy lagoon coast, which is mainly distributed in the sections from Baohujiao to Tongguzui and from Boao to Dahuajiao.In the Dahuajiao Meishan coast section, except for the rocky coast, the rest are basically sandy coasts, with a total length of nearly 300 kilometers.In the Meishan Changhua River estuary section, the sandy coast is mainly composed of sand levees, with a total length of nearly 200 kilometers, which is almost continuously distributed in the entire bank section.The sandy coastline of the Changhua Jiangkou Baohujiao Shore section is about 340km long, of which the Changhua Jiangkou Yangpu Shore section is about 100km long, the Danzhou Guangcun section is about 20km long, the Lingaojiao section is about 25km long, the Chengmai Ma Village Wenchang Baohujiao Shore section is about 170km long, and the rest of the sporadic shore sections are about 25km long.[14]
gulf
Hainan Island is surrounded by the sea, with a long and winding coastline (up to 1584.6 km) (the new data is 1823 km[4]）There are 78 natural harbors of different sizes (there are 68 harbors of different sizes,[1]）The larger ports include Xiuying Port (also known as Haikou Port), Haikou New Port, Dongshui Port, Puqian Port, Macun Port in the north, Hainan Bay, Haikou Bay, Chengmai Bay, Houshuiwan, Baishamen, etc;Yulin Port, Sanya Port, Tielu Port, Xincun Port, Li'an Port, Sanya Bay, Yazhou Bay, Yalong Bay, Haitang Bay, Lingshui Bay, South Bay, Xiangshui Bay, etc. in the south, Qinglan Port, Boao Port, Wuchang Port, Tanmen Port, Shimei Bay, Riyue Bay, Nanyan Bay, Dahuajiao, etc. in the east;In the west, Basuo Port, Yangpu Port, Baimajing Port, Gancheng Port, Lingtou Port, Yangpu Bay, Beili Bay, Qizi Bay, etc. are rich in resources and superior in environmental conditions.Haikou Port, Sanya Port, Yangpu Port, Basuo Port and Qinglan Port are the five major ports in Hainan.[13][15-16]
Soil vegetation
Announce
edit
Soil distribution
Soil of Hainan IslandHorizontal zonalityNot obvious, zonal soil isLatosol。Because the terrain of Hainan Island is high in the middle and low in the periphery, both soil forming conditions and soil distribution are gradually changing from the central and southern mountains to the surrounding areas.The soil distribution is significantly affected by the topography. The soil of the island is distributed in several concentric circles, which are distributed in turn around the central mountains: the outermost ring is the coastal sand distributed around the modern coastal terrace of the island, with an altitude of only 1 meter;The secondary outer ring is a zonal soil - lateritic soil, which is mainly distributed in terraces, platforms and hills with an altitude of 350 meters (or 400 meters).As there are wide terraces, platforms and hills along the coast of the northern part of the island, the ring of soil distribution in the northern part of the island is wide.The southern part of the island is located in the middle of the mountain area and is south, even close to the coast, and the soil ring is narrow.The central and southern mountains of the island are yellow soil, with an altitude of more than 400 meters.[17]
Vegetation distribution
Hainan has superior hydrothermal conditions, rich and diverse vegetation types, belonging to tropical and tropical island vegetation types.According to the survey, there are 259 families, more than 1300 genera, 4200 species of plants and more than 800 kinds of trees in Hainan Island, of which the tropical species account for 83%.In 1995, the forest area of the province reached 1.637 million hectares, including 839000 hectares of natural forests and 827000 hectares of artificial forests. The forest coverage rate has reached 48.7%.
Tropical monsoon rain forests are distributed in areas with periodic alternating dry and wet seasons. They are more or less deciduous in dry season and evergreen in wet season. Tropical monsoon rain forests in Hainan are divided into evergreen monsoon rain forests and deciduous monsoon rain forests.[18]
Evergreen seasonal rainforest is similar to tropical rainforest in the primary forest, but its appearance is inferior to that of rainforest. It is mainly distributed in low mountains, hills and platform areas below 750 meters above sea level, especially in the southeast hills and low mountains.The main precious woods are: green bark, litchiPhalaenopsis, YinggemuPhoebe oleifera、HuangtongEtc.
The deciduous monsoon rain forest is mainly distributed in the hills and mesas below 500 meters above sea level in the west and south of Hainan, and the community is relatively low.Common vegetation includesPachyderma、Quercus acutissimaBaige, Luguo, Pingmai, etc.[18]
Air roots in the tropical rain forest of Baihualing, Hainan
（2） Tropical rainforest
The tropical rainforests in Hainan Island are actually valley rainforests and mountain rainforests.Gully rainforest is distributed in valley areas below 900m above sea level, such as Jianfengling, Diaoluo Mountain, Kafaling and other mountains. The main tree species are:Chicken feather pine, butterfly treesMaternal birth、Green phoebe、Hainan YangtongEtc.Mountainous rainforests are mostly distributed between 750 and 1200 meters above sea level in Jianfeng Ridge, Macaque Ridge, Mayu Ridge, Diaoluo Mountain and other places. They are large and mostly primary forests. The main tree species are:Lu Junsong, thick woodSlope horst、Sapotaceae 、padauk 、YoudanEtc.Valley rainforest and mountain rainforest are important water source forests in Hainan Island, and are also valuable tropical timber forests and medicinal materials production bases.[18]
（3） Evergreen broad-leaved forest
Evergreen broad-leaved forest is a type of vertical mountain distribution, which is distributed on the mountains of Hainan Island. It is generally distributed in the mountains above 1000 meters above sea level, and can be divided into mountain evergreen broad-leaved forest and mountain top dwarf forest.The former species include: Lu Junsong, Hainan poplarPinus fenzeliana 、Castanopsis fargesii、Quercus flavipectus；The tree species of the latter include: thick oak, five split woodPachyderma odorata, tanninholly、Rhododendron hainanense Etc.Mountain evergreen broad-leaved forest and montane elfin forest are also one of the important water source forests in Hainan Island.[18]
（4） Mangrove
Mangroves in Hainan are divided into beach mangroves and coastal semi mangroves.Beach mangroves are distributed in deep silt and relatively closed bays or estuaries, areas below the high tide line, and the larger distribution areas are Qiongshan East Zhai Port, Wenchang Puqian Port, Qinglan Port, Danzhou Xinying Port, Lingshui Xincun Port, etc.Tree species include mangroveOlive、Red sea orchid、Sonneratia japonicaandMelia azedarach。Coastal semi mangroves are distributed in coastal areas above the high tide line, and are often connected with mangroves in a strip distribution, with a small area.Main tree species include:Sea Hibiscus、Begonia fruit、Sea mango、Coconut、Jatropha curcas, Shuiwanhua, etc.[18]
Quercus platycladus in the tropical rain forest of Jianfengling, Hainan
（5） Coniferous forest
The pure coniferous forest in Hainan Island is small in area. It can only be seen in the South Asian pine on the hills and platforms and in the bamboo Berlin on the sandy soil on the eastern coastal platform. The current vegetation only includes Bawangling and Songtao in Qiongzhong County. Natural pure forests are reserved, and Pinus hainanensis is the main tree species.Among the natural vegetation in HainanShrubbery, thorn shrub and grassland.[18]
Artificial vegetation
Artificial vegetation is the product of human economic activities on land use.Hainan Island is the main base for the development of tropical cash crops in China, with rich varieties of cultivated crops, diverse cultivated communities, and mainly tropical.The main tree species are Casuarina equisetifolia and eucalyptus, which form coastal protection forests. In 1995, the provincial protection forests were about 299000 hectares, and the main economic forests were rubber, citronella, pepper, mango, banana, etc.In 1995, the planting area of tropical crops in the province reached 4420000 hectares, accounting for 12.5% of the total land area, including 368000 hectares of rubber planting area.Crops mainly include: rice, sweet potato, cassava, peanuts and sugarcane.In 1995, the rice planting area of the province was 3940000 hectares, accounting for 11.1% of the total land area.[18]
Forest distribution
In Hainan Island, forest resources are distributed in the central, southwest and southeast mountain areas, that is, Wuzhi Mountain, Yingge Mountain, Limu Mountain, Shihan Mountain, Baima Mountain, Jiaji Mountain, Nanxi Mountain, Nangao Mountain and Futou Mountain in Baisha County, Jiayang Mountain, Baoyou Mountain and Kafa Mountain in Ledong County, Haowu Mountain, Shengmao Mountain, Sifang MountainNanlin Ridge, Baolong Ridge and Yaliang Ridge in Sanya City, Ma'an Ridge and Macaque Ridge in Dongfang County, Baomei Ridge in Changjiang County, Niutu Ridge, Tongtie Ridge, Liulian Ridge, Dongling Ridge and Jianling in Wanning City, Huishan Mountain in Qionghai City, Lumuwan Bay in Danzhou City, Huangzhu Ridge in Tunchang County and Renxing Mountain in Chengmai County.[18]
There are five most important tropical forest areas in Hainan Island: ① Wuzhi Mountain tropical virgin forest area; ②Bawang Ridge; ③Jianfengling forest area; ④Diaoluo Mountain forest area; ⑤Limu Mountain forest area.These forest areas are rich in forest resources and rich in precious tree species.The five major forest areas are all water source forests and water and soil conservation forests, which play an important role in regulating climate, conserving water resources, and preventing typhoons.In addition, the artificial forests in Hainan Island are mainly distributed in the coastal zone around the island and various state-owned farms of the Bureau of Agricultural Reclamation.[18]
Climatic characteristics
Announce
edit
Hainan Island has a tropical monsoon marine climate.The basic characteristics are: the four seasons are not clear, summer is not hot, winter is not cold, the annual temperature range is small, and the annual average temperature is high;It is obvious in dry season and rainy season, dry in winter and spring, rainy in summer and autumn, and tropical cyclones;There are abundant light, heat and water resources, and frequent climatic disasters such as wind, drought and cold.The annual average temperature is 22.5-25.60C, the annual sunshine hours are 1780-2600 hours, the total solar radiation is 4500-5800 MJ/m2, and the annual precipitation is 1500-2500 mm (about 1000 mm along the western coast).[19]
sunshine
Hainan Island is located to the south of the Tropic of Cancer, with a large solar altitude angle throughout the year.The sun was at the zenith twice before and after the summer solstice, and at noon, the solar altitude angle was 84 ° 45 ′ - 86 ° 45 ′;Even on the winter solstice, at noon, the solar altitude angle is 46 ° 05 ′ - 48 ° 05 ′.There is little difference in the day length between the summer solstice and the winter solstice, so the solar radiation energy is quite abundant and the sunshine is sufficient. The annual total solar radiation is 4600~5800 MJ/m2, and the annual sunshine hours are 1793~2590 hours. This lays the foundation for the formation of tropical climate.Hainan Island is located in the East Asian monsoon region, which is obviously affected by the monsoon.Both the east wind belt system and the west wind belt system affect it.[20]
air temperature
The annual average temperature in Hainan is 22.5~25.6 ℃, with the lowest in Qiongzhong in the middle and the highest in Sanya in the south.The isotherm curves southward in an arc distribution, increasing from the central mountain area to the surrounding coastal areas, and the 23 ℃ isotherm is closed in the central mountain area.Due to the regulation of the sea, the annual variation of temperature in Hainan is generally small, ranging from 8 to 10 ℃ in most areas, and the smallest temperature in Sanya (7.6 ℃).It is generally 5~10 ℃ lower than that in mainland China.[21]
precipitation
The annual average rainfall in Hainan is 923~2459 mm.Isohyets are distributed in a ring shape, with more in the middle and east and less in the west;There are many mountains and hills and few coastal plains;The rainy center is located from the west of Wanning to Qiongzhong, and the rainless area is located along the coast of Dongfang City.Qiongzhong County, the rainy center, has an average annual rainfall of 2458.5 mm, the maximum annual rainfall of 3759.0 mm (1978), and the minimum annual rainfall of 1398.1 mm (1959).In Dongfang County, where there is little rainfall, the average annual rainfall is 922.7 mm, the maximum annual rainfall is 1528.8 mm (1980), and the minimum annual rainfall is 275.4 mm (1969).The straight-line distance between Qiongzhong and the East is less than 150 kilometers, and the difference in rainfall is so great.[21]
The seasonal distribution of precipitation in Hainan Island is uneven, with more rainy season and less rainy season.It is rainy season from May to October every year. The total rainfall is about 1500mm, accounting for 70%~90% of the annual rainfall. The rain sources mainly include frontal rain, hot thunderstorm and typhoon rain;From November to April of the next year, there is a little rainy season, accounting for only 10%~30% of the annual rainfall. Drought often occurs in the little rainy season.[22]
Water system hydrology
Announce
edit
River system
Many rivers, large and small, flow into the sea from the central mountainous or hilly areas, forming a radial island water system.[23-24]There are 154 rivers flowing into the sea alone on the island, and the average catchment area of each river is only 220 square kilometers.Among them, 39 have a catchment area of more than 100 square kilometers, accounting for 84.4% of the island area;There are 115 rivers with a catchment area of less than 100 square kilometers, accounting for only 15.6% of the island area.The main rivers areNandu River、Changhua RiverandWanquan RiverThe drainage areas are 7033, 5150 and 3693 square kilometers respectively.The area of the three major river basins accounts for 47% of the island area.Lingshui River and Ningyuan River cover an area of 1000~2000 square kilometers.Rivers with a drainage area of 500~1000 square kilometers include Zhubi River, Wanglou River, Wenlan River, Beimen River, Taiyang River, Tengqiao River, Chunjiang River and Wenjiao River.[23-24]
Haikou Section of Nandu River
Nandu RiverOriginating from Nanfeng Mountain in Baisha County, it runs obliquely through the northern part of the island, passing through Baisha, Qiongzhong, Danzhou, Chengmai, Tunchang, Ding'an, Qiongshan, and entering the sea in Haikou City, with a total length of 334 kilometers, a total drop of 703 meters, a drainage area of 7176.5 square kilometers, and 19 tributaries of more than 100 square kilometers.Xichang River is the largest tributary of the Nandu River, with a length of 257 kilometers.[24-25]
Ledong County Section of Changhua River
Changhua RiverIt originates in the north of Wuzhi Shanxi, runs across the west of Hainan Island, flows through Qiongzhong, Baoting, Ledong and Dongfang, and ends at Changhua Port, with a total length of 231 kilometers, a total drop of 1270 meters, a drainage area of 5070 square kilometers, and 10 tributaries of more than 100 square kilometers.Tongshishui is the largest tributary with a length of 61.8 km.[24-25]
Qionghai Section of the Lower Wanquan River
Wanquan RiverIt originates from Fengmen Ridge of Wuzhi Mountain, flows through Qiongzhong, Wanning, Tunchang and Qionghai, and enters the sea at Boao Port, with a total length of 163 kilometers, a total drop of 523 meters, a drainage area of 3683 square kilometers, and 8 tributaries over 100 square kilometers.Ding'an River is the largest tributary, about 88 kilometers long.[24-25]
Surface hydrology
distribution
The main characteristics of the water system in Hainan Island are as follows:.(2) Due to the short river and steep slope, as well as the influence of terrain and climate, the rainstorm intensity is high, the flood peak is high, the duration is short, and the flood rise rate is large. The ratio of maximum flow to minimum flow is up to thousands of times, for example, the ratio of Baoqiao Station on Changhua River is 5970 times.(3) The small flow lasts for a long time, and the punching and cutting is not strong, so that many small and medium-sized rivers are shallow and narrow, and the flood discharge capacity is low. The farmland on both banks is often damaged by flooding.(4) Rivers in mountainous areas have steep slopes and rapid water flow, with concentrated drop, and good hydropower resources.The theoretical reserve is 995000 kW, and the exploitable capacity is 772100 kW.(5) The sediment concentration is small, and the average suspended load sediment concentration for many years is 0.055~0.197 kg per cubic meter.(6) It is not frozen throughout the year.[26]
runoff
The average annual runoff depth of Hainan Island is 909 mm, with the largest being 1457 mm in Qiongzhong County and the smallest being 547 mm in Dongfang City.The average annual runoff coefficient of the island is 0.51, and the average annual runoff is 30.8 billion cubic meters.In which, P=10% of the wet year, the runoff is 49 billion cubic meters;P=50% in normal year, the runoff is 290m3;P=75% of the low water year, the runoff is 20.9 billion cubic meters;The runoff is 15.1 billion cubic meters in the dry year with P=90%, and 12.6 billion cubic meters in the extremely dry year with P=95%.[26]
Hainan has a hot climate and high surface temperature.According to the long-term monitoring of the provincial hydrological station, the average annual surface water (river) temperature is between 20 ℃ and 30 ℃.Runoff distribution characteristics: (1) The annual average runoff is deep, but the regional distribution and annual distribution are uneven, and the annual variation is large;(2) The annual average runoff depth decreases from the central mountainous area to the surrounding coastal area, which is consistent with the precipitation trend. The average runoff depth is high in the middle and low in the surrounding area, large in the east and small in the west, and the difference between high and low areas is large.[26]
Like precipitation, the average runoff in flood season accounts for 82% of the total annual runoff in the Nandu River basin, 81% in the Changhua River basin, and 68% in the Wanquan River basin;66% in the east, 79% in the middle, 85% in the west and 79% in the north of the island.[26]
The interannual variation of runoff is large, with a variation coefficient of 0.4~0.55, and there is great difference between flood and dry seasons.The ratio of the measured annual runoff in the maximum year to the minimum year is up to 4-7 times, and the ratio of the maximum peak flow to the minimum flow is up to thousands of times.[26]
Sea area hydrology
Hainan Island is located between the Beibu Gulf, Qiongzhou Strait and the South China Sea.It is mainly restricted by the hydrological environment of the South China Sea.
tide
The tide phenomenon in Hainan Island is mainly the Pacific tide waveBashi ChannelandBalintong Straitget intoSouth China SeaLater, the tidal type is complex.There are three types of coastal tidal current: regular diurnal tidal current of surface tide, which is distributed from Sanya Port to Yinggehai, east of Qiongzhou Strait, and Xinjiang coast;Irregular diurnal tide, distributed in Haikou Port, Qinglan Port and Basuo Port;The irregular semidiurnal tide is distributed in Gangbei Port, Lingshuijiao Port and Yangpu Port.There are also three kinds of bottom currents: regular all day currents are distributed from Haikou Port to Baohujiao, Sanya Port to Yinggehai;Irregular diurnal tide, distributed from Basuo Port to the west mouth of Qiongzhou Strait;The irregular semidiurnal tide is distributed from Qinglan Port to Gangbei Port.[27]
wave
In Yubao Port and Baishamen, the waves are mainly northward.The frequency of occurrence is: jade bag 87%, the most northeast wave, 29%;The Baishamen is 73%, and the northeasterly wave is the most, 39%.[27]
Tongguling in the northeast of Hainan Island, Yalang Bay and Yulin in the south, and Yingge Sea in the southwest are dominated by southerly waves.In the coastal area of Tongguling, the frequency of wave occurrence is 69%, and the maximum southeast wave is 34%;In Yalang Bay, 57%, the most southerly waves, 31%; Yulin Port, 83%, the most southwesterly waves, 25%;Yinggehai, 61%, Southeast wave and South wave are the most, 16%.[27]
At Dongfang (eight stations) in the west of Hainan Island, the distribution of waves in all directions is different from that at the above stations.There are few waves in the range of northeast east southeast east southeast southeast east, and the frequency of each direction is less than 0.5%. The waves in this sea area are mainly concentrated in the southwest and north directions.In the range of south to southwest to west, the frequency is 44%, with the largest number of southwest waves, 17%;In the NW-NE-NE China Sea region, the frequency of occurrence is 48%, and the waves in the northwest and northeast are the most frequent, with the frequency of 1.9%.[27]
The waves around the island are relatively large, with the highest annual average wave height on the north and east bank, and the lowest wave height on the south bank.The average wave height in the southerly direction of Yubao Port and Baishamen South Station in the north of the island is small, 0.2~0.4 meters;While Yubaojiao is larger in both the west and east directions, ranging from 0.6 to 0.7 meters, and Baishamen is larger in the northeast direction, ranging from 0.6 to 1.0 meters;Yalang Bay and Yulin in the south of the island are larger by the west, the former is 0.7~0.8 meters, and the latter is 0.5~0.8 meters;The other directions are smaller. Tongguling in the northeast of the island is the largest in the northeast direction, which is 1.1 meters (the highest on the whole coast of Hainan Island). The other directions are 0.8~1.0 meters.In the east of the west of the island, the waves in the east and west directions are small, 0.3~0.7 meters;Large in the south direction, 0.9~1.0m;Yinggehai in the southwest has little difference in all directions, ranging from 0.5 to 0.9 meters.[27]
Except that the average period of Yalang Bay is obviously larger, the average period of other observation stations is close.The average wave period along the coast of the island is 2.9~4.6 seconds, while Yalang Bay is 8.1 seconds long, which is full of entertainment benefits of bathing and surfing.[27]
water temperature
The coastal sea water temperature level distribution is characterized by increasing from north to south, high in the west and low in the east, low in winter along the coast and high in the open sea, and high in summer along the coast and low in the open sea.The water temperature difference between east and west coasts is about 9 ℃.In winter, the sea water temperature in Haikou is 18.7 ℃, while the sea water temperature in southern Sanya has increased to 22 ℃, 4-5 ℃ higher than that in the Pearl River port section, which is the highest coastal section of China in winter.
The coastal area of Hainan Island has shallow water depth, and the annual change of seawater temperature is greatly affected by climate.It has the characteristics of great age difference and rapid change.The highest value of water temperature occurs in summer (May to September), and the lowest value occurs in winter (January to February). The annual range is between 7 and 11 ℃. The annual variation of water temperature increases from south to north.[27]
salinity
The salinity of the surface seawater around Hainan Island has the characteristics of reverse increase from the coast to the open sea and great difference in temporal and spatial distribution.The average annual salinity of the whole coast is 32.64, slightly higher than that of the northern coast of China (salinity 28~30).From spring to early summer (March to May), the salinity is 31.56~34.48, and in autumn (September to October), the salinity is low, generally 18.55~32.11;Except for the high salinity area from Qinglan Port to Lingshui Bay where the salinity increases to 34.47 due to upwelling, the salinity of the rest of the bank sections is lower than that of the west and southwest bank sections.The extreme salinity in the East and Yinggehai are 36.0 and 36.2 respectively, which is 5% higher than the salinity (30-31) in the east, middle and west of Guangdong.Under the climate conditions of high temperature, long sunshine and large net evaporation, it is beneficial to sun salt and should be classified as a salt field area.Abundant sea salt has laid the foundation for the development of salt chemical industry.[27]
Water color and transparency
The coastal water color of Hainan Island changes between No. 2 and No. 21. The distribution trend of water color generally increases with the increase of water depth from the coast to the outside, and has the characteristics of low water color in the eastern and southern coastal areas and obvious seasonal changes.The change range of transparency is 0.5~20m, and its change trend is similar to the water color, that is, the deeper the water depth, the greater the transparency.The eastern and southern coastal areas are more transparent, while the western and northern areas are less transparent.Generally, the transparency is great in spring and summer, and there are obvious seasonal changes in autumn and winter.[27]
natural resources
Announce
edit
Hainan Island is the second only to Taiwan Island in ChinatropicIsland provinces are known as the "few unpolluted pure lands" in the world.The island is always spring all the year round,forest coverageMore than 50%.Hainan is a colorful world, with five tourism elements of sunshine, sea water, beach, green and air, and unique tropical island natural scenery.
water resource
The average annual runoff of the island is 909mm,Average annual runoff30.8 billion cubic meters.The underground water reserve is 7.9 billion cubic meters, of which 5.35 billion cubic meters is the river base flow (i.e. the amount of repeated calculation), so the average annual total water resources is 33.35 billion cubic meters.The average annual rainfall of Hainan Island is 1758 mm, and the rainfall is 59.63 billion cubic meters.[28-29]
Hydropower resources
Hainan Island has abundant rainfall, numerous rivers and abundant hydropower resources. After calculating the main and tributaries with a rainfall collection area of more than 100 square kilometers one by one, the theoretical reserve is 995000 kilowatts.Among them, the Changhua River, Wanquan River and Nandu River account for 741500 kilowatts, accounting for 75%.The exploitable amount of hydropower resources in the island is 772100 kW, of which 629300 kW is for the three major rivers, accounting for 82%.[30]
By the end of 2000, 304 hydropower stations had been developed in the island, with an installed capacity of 536900kW, accounting for 69.3% of the exploitable capacity (the national installed capacity of hydropower only accounts for 19.3% of the exploitable capacity).[30]
Table of Hydropower Resources in Hainan Island
Water system name
Theoretical quantity
Exploitable quantity
Developed installed capacity
Developed installed power generation
Nandu River
twenty-one point nine eight
eight point three six
thirty-seven thousand and two hundred
five point seven eight
Wanquan River
twenty-one point six two
twenty-one point one seven
seventy-seven thousand and four hundred
nine point six nine
Changhua River
thirty point five five
thirty-three point four zero
one hundred and two thousand and seven hundred
twenty-seven point one zero
Other river systems
twenty-five point three five
fourteen point two eight
sixty thousand and four hundred
eleven point one two
total
ninety-nine point five zero
seventy-seven point two one
two hundred and seventy-seven thousand and seven hundred
The flora of Hainan is tropical in nature due to the absolute predominance of tropical elements, and is rich in plant species.[31]
The natural vegetation types on Hainan Island include evergreen seasonal rainforest, deciduous seasonal rainforest, valley rainforest, mountain rainforest, mountain evergreen broad-leaved forest, tropical coniferous forest, coastal mangrove, savanna, etc. The artificial vegetation types include rubber forest, coconut forest, litchi forest, paddy field, etc.Tropical rain forest and seasonal rain forest should be the zonal vegetation type of Hainan Island.As a result of long-term development and utilization, the flat tropical rainforest has been damaged, and the secondary type occupies an important position.There are valley rainforests and mountain rainforests in high altitude mountains such as Jianfeng Ridge, Bawang Ridge, Diaoluo Mountain and Wuzhi Mountain.Evergreen monsoon rain forest is distributed in the wet low mountains and hills in the east, and deciduous monsoon rain forest is distributed in the low mountains and hills in the dry areas in the west.Mountainous evergreen broad-leaved forest and montane elfin forest are vegetation types in the upper part of mountains with an altitude of more than 800m. They form a vertical pedigree with the rainforest and monsoon forest in the lower part of the mountain.[31]
The floristic elements of the vegetation in Hainan Island are almost all tropical species, because they have not been directly affected by the Quaternary glaciers, and there are many ancient plants preserved.The flora is rich. There are more than 4600 vascular plants in the island, belonging to 233 families and 1201 genera, of which about 80% belong to the Pantropical Family and Subtropical Family. The typical tropical families are Dipterocarpaceae, Annonaceae, Myristicaceae, Palmae, Sapindaceae, Mangrovaceae, etc. The tropical Lauraceae and Myrtaceae are particularly rich,The main components of the arbor community are Lauraceae, Euphorbiaceae, Leguminosae, Annonaceae, Fagaceae, Moriaceae, Myrtulaceae, Magnoliaceae, Dipterocarpaceae, Lamiaceae, Meliaceae, and some gymnosperms. The undergrowth plants mainly include Rubiaceae, Myrsinaceae, Melastomaceae, Euphorbiaceae, Euphorbiaceae, Palmae, Bambusoideae, Moriaceae, and Rutaceae, as well as a large number of ferns.There are few plants in temperate families. Carpinus, Acer, Purple Tree, Azalea and Torreya are only distributed in the upper part of mountains or limestone areas.[31]
Animal resources
Hainan Island has superior natural conditions and food is available all the year round, which is conducive to the growth and reproduction of all kinds of animals and plants.The number of animal species is one of the regions with the largest number of animal species per unit area in China's small regions.There are 112 kinds of mammals, 355 kinds of birds, 116 kinds of reptiles, 39 kinds of amphibians, more than 70 kinds of freshwater fish, more than 600 kinds of marine fish, about 1320 kinds of marine invertebrates, about 880 kinds of insects, and more than 260 kinds of other invertebrates.[32]
According to the zoogeographical division, Hainan Island belongs to the same trade area between the sea and Xinjiang in the southern region of the Oriental boundary. Among the birds and animals on the island, the Oriental boundary composition (more than 80%) is the main one, while the Palaearctic boundary composition is very few, and it is rich in tropical and subtropical rainforest composition, with fruit, insects or nectar as the main food.[32]
According to the use and economic value of animals, they can be roughly divided into: (1) rare ornamental animals, including Hainan black gibbon, Hainan slope deerclouded leopardPeacock pheasant, Hainanshan partridge, python, etc;(2) Fur animals include Hainan otterSmall claw otter、Ferret badgerwait;(3) Leather animals, includingwild boar、Red muntjacwait;(4) Meat animals, including Hainan rabbit, wild boar, red muntjacRaw chicken、turtledove、sea turtleAnd all kinds of fish, molluscs, shrimps and crabs, etc;(5) Medicinal animals, including black bearPangolin, brown winged crow and cuckoovaranid、Hawksbill, tortoises, snakesHailong、a hippocampus、Pinctada martensii、Abalone, cantharides, etc.[32]
There are 105 species of rare animals under national protection in Hainan Province, among which the first class protected animals are Hainan black crested gibbon, Hainan slope deer, Hainanshan partridge, peacock pheasantChristmas Frigatebird 、Nautilus16 kinds;Class II protected animals, includingmacaque, pangolin, Hainan water deer, Hainan rabbit, silver pheasant, pheasantGreen Turtle, tortoise shellPalea steindachneri89 species, including tiger spotted frog.[32]
Wildlife resources change with the change of vegetation conditions. Before the 1960s, Hainan Island was rich in animal resources, with considerable species and quantity, and wide distribution areas.Later, with the destruction of ecological conditions, the habitat of animals continued to shrink, coupled with the indiscriminate hunting and killing of human beings, the species and quantity of wild animals were significantly reduced, and the distribution area was also sharply reduced.Hainan black gibbon, distributed in 10 counties of Hainan Island in the 1950s, has more than 2000 heads;In the 1980s, only Bawangling, Jianfengling and Wuzhishan tropical forests were distributed, with a total number of less than 20.In addition, the precious animal resources such as Hainan slope deer, clouded leopard, peacock pheasant, Hainanshan partridge, giant lizard, nautilus and so on are decreasing day by day. One third of the bird species on the island have been difficult to see in recent years and tend to be extinct.The excessive fishing of marine fisheries and the pollution of inland waters, such as the use of explosives, electric fish and poisonous fish, have led to the destruction of animal resources and their ecological environment. The situation is serious and alarming.In view of this, relevant government departments have taken a series of protective measures. Since 1965, nature reserves have been established. By 1990, Hainan Province has established 58 kinds of nature reserves, including 48 terrestrial nature reserves and 10 marine nature reserves.There are 5 national nature reserves, 26 provincial nature reserves and 27 county (city) nature reserves.[32]
mineral resources
Hainan has many kinds of mineral resources.There are 88 kinds of minerals found in the province, 69 of which have been listed in the statistics of mineral resources reserves, and 684 places of origin.Hainan's mineral resources mainly include oil, natural gas, ferrous metals, nonferrous metals, precious metals, rare metals, metallurgical auxiliary raw materials, chemical raw materials, building materials, other non-metallic minerals, groundwater, hot mineral water and drinking natural mineral water.The advantageous minerals with proven reserves in the forefront of the country include oil, natural gas, sand for glass, ilmenite, zircon placer, gem, rich iron ore, bauxite (three water type), granite for decoration, drinking natural mineral water, hot mineral water, etc.
There are 19 proven large-scale deposits of glass sand in Hainan Island, which are mainly distributed in Wenchang, Danzhou, Changjiang, Dongfang, etc.Ilmenite placers are mainly distributed on the east coast of Hainan Island. There are 70 proven deposits, including 4 large deposits and 16 medium deposits.Zircon placer has been proved to have 5 large deposits, 6 medium deposits and 59 small deposits, which are mainly distributed in Wenchang, Qionghai, Wanning, Lingshui and other cities and counties.Two small gem deposits have been proved, which are located in Wenchang.Rich iron ores are distributed in Shilu Town, Changjiang River, with a reserve of 298 million tons, which is one of the rare rich iron ores in China.One large bauxite deposit has been proved, which is located in Pengcai area in the north of Hainan Island.Granite for veneer is mainly distributed in Tunchang, Ledong, Sanya, Dongfang, Baisha and other cities and counties.Drinking natural mineral water is found in all cities and counties.[1]
On the evening of October 19, 2022, CNOOC announced that Baodao 21-1, the first deep-water deep atmospheric field in China, was found in Qiongdongnan Basin in the southeast sea area of Hainan Island, with proven geological reserves of more than 50 billion cubic meters.[36]
Sea salt resources
Hainan Yinggehai Salt Field
Hainan Island is an ideal natural saltern. In the arc area hundreds of miles from Sanya to the eastern coast, many harbors and beaches can be used for drying salt.Yinggehai, Dongfang, Yuya and other large-scale saltworks have been built, includingYinggehai Salt Farmbest-known.[1]
social culture
Announce
edit
Administrative system
Administrative divisions on Hainan Island
According to ancient records, Hainan Island and the South China Sea Islands had already belonged to the Central Plains Dynasty in the pre Qin period.In the Xia, Shang and Zhou dynasties, Hainan was a southerner from Yangyue. Fishermen along the South China Sea have paid tribute to the imperial court for pearl shellfish, hawksbill and other local specialties.In the Qin Dynasty, there were three prefectures in the south of the Five Ridges, namely Guilin, Nanhai and Xiangjun. Hainan was on the edge of Xiangjun.At the turn of Qin and Han Dynasties, Hainan was under the jurisdiction of Nanyue.In the first year of Yuanfeng (110 BC), Emperor Wu of the Western Han Dynasty set up Zhuya and Dan'er Counties in Hainan for the first time, with jurisdiction over 16 counties. The islands in the South China Sea were included in the territory of China, under the jurisdiction of Zhuya County.Since then, the evolution of the establishment has changed repeatedly. In the Tang and Song Dynasties, Hainan Island gradually formed a pattern of four states in the southeast, northwest and northwest, which became the basis of the administrative system in the past dynasties.Before the Ming Dynasty, Hainan was once subordinate to Huguang and Guangxi provinces. At the beginning of the Ming Dynasty, Hainan was changed to Guangdong province.During the Republic of China, Qiongya Road and Hainan Special Administrative Region were set up successively, which were still subordinate to Guangdong.After liberation, Hainan has long established an administrative office or a regional office as the agency of Guangdong Province.In October 1984, the People's Government of Hainan Administrative Region was established for the first time as a first level local government agency.[3]
Haikou City
On April 13, 1988,The First Session of the Seventh National People's CongressThe Decision on the Establishment of Hainan Province was passed, which divided the Hainan Administrative Region from Guangdong Province and established Hainan Province separately.The jurisdiction includes Hainan Island, Xisha Islands, Zhongsha Islands, Nansha Islands and their sea areas;The subordinate administrative organizations include Haikou City, Sanya City (prefecture level), Tongshi City (county level), Qiongshan County, Wenchang County, Qionghai County, Wanning County, Ding'an County, Tunchang County, Chengmai County, Lingao County, Danzhou, Qiongzhong Li and Miao Autonomous County, Baoting Li and Miao Autonomous County, Dongfang Li Autonomous County, Ledong Li Autonomous County, Lingshui Li Autonomous County, Baisha Li Autonomous County19 cities and counties including Changjiang Li Autonomous County and Xisha, Zhongsha and Nansha Islands offices.The provincial capital is located in Haikou.[3]
Since then, the administrative system has changed slightly. As of September 2015, Hainan Province has 27 cities, counties (districts), including 4 prefecture level cities, 5 county-level cities, 4 counties, 6 autonomous counties, 8 districts, 218 townships (including sub district offices), including 21 townships, 175 towns, and 22 sub district offices.Prefecture level cities: Haikou, Sanya, Sansha, Danzhou;County level cities: Wuzhishan City, Wenchang City, Qionghai City, Wanning City, Dongfang City;County: Ding'an County, Tunchang County, Chengmai County, Lingao County;Autonomous counties: Baisha Li Autonomous County, Changjiang Li Autonomous County, Ledong Li Autonomous County, Lingshui Li Autonomous County, Baoting Li and Miao Autonomous County, Qiongzhong Li and Miao Autonomous County.[33]
Population and nationality
Hainan is a place where many ethnic groups live together. There are more than 30 ethnic groups, including Han, Li, Miao, Hui, Zhuang and Yao.At the end of 1990, the total registered population of the province was 6.5123 million, of which 1.0912 million were ethnic minorities (the largest number of Li ethnic minorities was 1.007 million), accounting for 16.76% of the total population.The population density is 193 people/km2.There are more than 2 million overseas Chinese and Hong Kong and Macao compatriots living overseas in the province, and more than 1 million returned overseas Chinese and their relatives in the province. It is one of the main hometown of overseas Chinese in China.[3][34]
According to the population change sampling survey, the province's permanent population at the end of 2019 was 9.4472 million, an increase of 104000 over the previous year, of which 5.5956 million were urban permanent residents, accounting for 59.23% of the total population (urbanization rate of permanent residents).The birth rate of the whole province is 12.87 ‰, the mortality rate is 6.11 ‰, and the natural growth rate is 6.76 ‰.[35]
tourist resources
Distribution of tourism resources on Hainan Island
Coastal landscape
Sanya coastal landscape
On the coastline of Hainan Island, the sand bank accounts for about 50%~6%, and the beach width varies from hundreds of meters to more than 1000 meters. The slope toward the sea surface is generally 5 degrees, extending slowly;Most places are calm, the sea water is clear, the sand is white as flocs, clean and soft;The bank is shaded by green trees, and the air is fresh;The sun is full and bright, and you can take sea bathing, sunbathing, sand bathing and wind bathing most of the year.From Haikou to the east coast of Sanya, there are more than 60 places that can be turned into bathing beaches.There are different types of coastal scenic spots along the coast of the island. On the east coast, the special tropical seashore forest landscape mangrove, and the unique tropical coastal geomorphic landscape coral reef have high ornamental value.Mangrove reserves have been built in Haikou Dongzhai Port, Wenchang Qinglan Port and other places.There are 22 promontories, 25 lighthouses, 68 bays, 26 lakes, 21 resorts, 31 scenic spots and 216 places of interest on the coastline.[1]
Mountain forest
Diaoluoshan
Hainan Island has 81 mountains with an altitude of more than 1000 meters, which are rolling, unique and magnificent.The famous Wuzhi Mountain, which is zigzag and shaped like five fingers at the top, the magnificent Yingge Mountain, the Dongshan Mountain with strange stones overlapping the peaks, the Taiping Mountain with waterfalls flowing down, as well as the Qixian Mountain, Jianfeng Mountain, Diaoluo Mountain, Bawang Mountain, are all popular places for mountaineering tourism and summer resort.Hainan's most distinctive mountains are densely covered with tropical primitive forests, including Ledong Jianfeng Ridge, Changjiang Bawang Ridge, Lingshui Diaoluo Mountain, and Qiongzhong Wuzhi Mountain. Among them, Ledong Jianfeng Ridge is the most typical.[1]
rare fowls and strange animals
In order to protect species and facilitate viewing, Hainan has established a number of wildlife nature reserves and training farms, including Changjiang Bawangling Black crowned Gibbon Reserve, Dongfang Datianpo Deer Reserve, Wanning Dazhou Island Swift Reserve, Lingshui Nanwan Peninsula Macaque Reserve, Tunchang Deer Farm, etc.[1]
River scenery
Nandu River, Changhua River, Wanquan River and other rivers, with intertwined beaches and lakes, winding and clear water, are good places for tourism and sightseeing, especially the Wanquan River scenery.There are many waterfalls, including Wuzhi Mountain Taiping Mountain Waterfall and Qiongzhong Baihualing Waterfall.There are also many reservoirs on Hainan Island, especially Songtao, Nanfu, Changmao, Shilu and other reservoirs, which are more beautiful than lakes.[1]
Geological landscape
Volcanic eruptions in history left many extinct craters on Hainan Island.The most typical one is the Shishan Mountain in Haikou, which has a double ridge with an altitude of more than 200 meters. There are two craters on the ridge, with a concave ridge in the middle. It looks like a saddle, also known as the Maanling.The Leihuling crater and Luojingpan crater near Shishan are also well preserved.There are many karst caves in various forms, including the famous Luobi Cave in Sanya, Qianlong Cave in Baoting, Emperor Cave in Changjiang, etc.The hot springs on the island are widely distributed. Most of them have low mineralization, high temperature, large water volume and good water quality. They are therapeutic hot springs, and the area where the hot springs are located has pleasant scenery.Xinglong Hot Spring, Guantang Hot Spring, Nanping Hot Spring, Lanyang Hot Spring, etc. are suitable for developing tourism integrating sightseeing, recuperation, scientific research, etc.[1]
Historic sites
Yazhou Ancient City
Historic sites mainly include the Five Gongci built to commemorate five historical ministers, including Li Deyu, who were exiled to Hainan Island in the Tang and Song dynasties, the Dongpo Academy, the site of Juqiong of Su Dongpo, a great literary magnate in the Northern Song Dynasty, and the Sugong Temple built to commemorate Su Shi, the Qiongtai Academy built by Lei Qiongbing of the Qing Dynasty and Jiao Yinghan, the tomb of Qiu Jun, a famous minister of the Ming Dynasty, and the tomb of Hai Rui, a great upright official of the Ming Dynasty,It is said that Ma Yuan, the general sent by Emperor Wu of the Han Dynasty to lead troops into Hainan, ordered the excavation of Fubo Well of Han Ma to save soldiers and horses, as well as Yazhou Ancient City, Weishi Temple, Wenchang Confucius Temple, etc.[1]
Revolutionary memorial
Red Detachment of Women Memorial Park
The revolutionary memorial sites in Hainan include the site of the First National Congress of the Communist Party of China in Qiongya, the site of Qiongya Column Headquarters, the Red Detachment of Women Memorial Park, Jinniuling Martyrs Cemetery, the Baisha Uprising Memorial Hall, the site of the Soviet government in Lingshui County, as well as the ancestral home and exhibition hall of Song Qingling, and the memorial hall of General Zhang Yunyi.[1]
ethnic customs
Li brocade display
The indigenous minorities in Hainan Island areLi nationality、Miao nationality、Hui nationalityIt retains many simple and honest folk customs and living habits, making Hainan's social style unique and colorful.Hainan is the only inhabited area of Li nationality in China. The Li nationality has a distinctive national culture and customs, which is of unique tourism value.[1]
Rural scenery
A large number of tropical crops grow on Hainan Island, greatly enriching the natural landscape.Visitors can not only enjoy the tropical pastoral scenery and increase their knowledge, but also taste tropical fruits to satisfy their taste.[1]
