1. Geographical Position
Before the National Assembly issued the Resolution 15/2008QH12 dated May 22, 2008 on merging whole Me Linh District to Ha Noi, Vinh Phuc has its natural land area of 1,371.47 km2, including 9 administrative units: Vinh Yen City, Phuc Yen Town and 7 districts: Lap Thach, Tam Duong, Binh Xuyen, Tam Đao, Vinh Tuong, Yen Lac, Me Linh. After the Government adjusting the provincial boundery according to the Resolution of the National Assembly, the natural land area of Vinh Phuc to 2012 is 123,861.62 km2, including 9 administrative units: (1 city, 1 town and 7 districts): Vinh Yen City, Phuc Yen town and the districts: Binh Xuyen, Lap Thach, Song Lo, Tam Duong, Tam Đao, Vinh Tuong, Yen Lac; 112 communes and 25 wards and townlets in total.
Vinh Phuc is bordered with 4 provinces and city: It is bordered to the North by Thai Nguyen and Tuyen Quang provinces with Tam Dao jungle and Sang Son Mountain as a natural border; to the West by Phu Tho Province with Lo River as a natural border; to the South by Ha Noi with Red River as a border; to the East by two districts Dong Anh and Soc Son of Ha Noi.
There are six different groups in Vinh Phuc:
- High degraded rock: apportioned in North of Huong Canh, centers of Lap Thach District and Tam Duong District, forming a strip stretching in the direction of Northwest-Southeast, including gneis rock rich in plagioclas, biotite, siminanite. In some sections, found quaztzit contained mica of Chiem Hoa formation.
- Original green sediment in red color: Allocated in the Southeast of Tam Dao, close to Soc Son (Ha Noi), including sandstone, red brownish schist, greenish, light violet embedded with reddish clay schist under Na Khuat formation.
- Original green sediment contained coal: Allocated in a narrow strip in Dao Tru Commune (Tam Dao). Its compositions are conglomerate, sandstone, schist, coal clay and coal layer. The upper part is: sandstone, agglomerated flour, darkish yellow schist, dark grey belonging to Van Lang formation. The Neogren sediment jutted out in the Southwest of Tam Dao District, embedded in between the fault of Chay River and Lo River, including the agglomerated flour and the blackish grey agglomerated clay conversed from the lower layers.
- Starchy sediment: The fourth sediment is allocated largely in The South of the Province, coming along the Red River and Lo River valleys, including pebble, gravel, sand, yellow clay, laterit weathered flower clay with motley colored, greenish grey clay, yellowish grey clay, kaolin, green clay, black grey of Ha Noi, Vinh Phuc, Thai Binh formation.
- Eruptive rocks: Allocated in the Northeast of the province, the whole Tam Dao range, including the real eruptiveness: ryolit daxit rock, ryolit porphyr contained rock crystal, feldspar, plagioclase. The second best eruptive ness, including ryolitporphyr contained big crystal, few quantity of feldspar in the form of small belt. The explosive eruptiveness: lens contained few breccias, volcanic bomb of Tam Dao formation. The Tam Dao eruptive rocks mainly are ryolite, some are daxite rocks.
- Penetrated Magma Rocks: belonging to Chay River formation complexallocated in the Northwest of Lap Thach District, including granodiorit, granit from small to big particles, granit 2, mica, granit muscovit from medium to small particles, and apit and pegmatit veins. The features of the rock are rich in aluminum and alkaline. The penetrated magma rocks are in the system of the fault of Northwest-Southeast direction, including the fault of Chay and Red Rivers.
In the North of Vinh Phuc is Tam Dao range lasting from Dao Tru Commune (Tam Dao)- a North peak of the province to Ngoc Thanh Commune (Puc Yen) - a East peak of the Province, with 30 km long. In the Southwest, Red and Lo Rivers, which create its topography gets slow down from the Northeast to the Southeast, and make the province three distinct regions, surround it: plain, low and medium mountain.
- Topography in the Plain: It includes 76 communes, wards and towns with the land area of 46,800ha. The plain includes the old alluvium and new alluvium zones. The old alluvium mainly formed by the alluvium of the big rivers as Red River, Lo River, Day River. The zone has a large area, including the communes of North Me Linh, Yen Lac, Vinh Tuong and South of Binh Xuyen District. The zone was formed in the Fourth Holoxen. The soil of this zone is fertile, an ideal fro intensified agricultural economy.
- Hill Topography: Including 33 communes, wards and towns with total land area of 24,900ha. This zone is good to develop the industrial trees, fruit trees and crops in connection with cattle breeding, and it also provide favorable conditions for shifting the plantation and breeding in the manner of food processing production.
- Low and medium hill topography: This zone has a land area of 56,300ha or 46.3% of total land area of the province. Streams and small rivers separate the topography of this zone. This is an advantage of the province as compared with the neighbor provinces, because it has favorable conditions for developing the industrial parks and ecological tourism. Tam Range itself possesses an area of 15,753ha of the National Forest Park.
Vinh Phuc is in the monsoon season, characterized by the climate of the Northern mountainous midland region.
- Temperature: Mean temperature is 23.5 - 250C. The highest temperature is 38.50C. The lowest temperature is 20C. However, it is affected by the topography so the difference of temperature between the plain and the mountainous zone is rather large. Tam Dao range is in 1,000m above the sea level so its mean temperature is 18.40C/year.
- Rainfall: Average rainfall in a year ranges from 1,400 to 1,600mm. The average rainfall in Vinh Yen station shows 1,323mm, while in Tam Dao is 2,140mm. The rainfall is not widespread but much rain is from May to October, standing for 80% of the total rainfall.
- Sunshine hours: An average sunshine in a year is 1,400 - 1,800 hours. The most sunshine months are June and July. The lowest is March.
- Wind: There are two main wind directions, Southeast is from April to September, and Northeast is October to March of the following year.
- Humidity: Its average is 83%. General speaking, the humility is not different between the plain, the inland and the mountainous zone.
- Vaporization: Its average is 1,040mm/year. From April through September is 107.58mm/month. From October to March next year is 71.72mm/month.
5.1 Surface hydrography: There are four main rivers running through Vinh Phuc, they are Red River, Lo River, Day River and Ca Lo River but classified into two main river systems: Red river and Ca Lo River. Their water reserve is quite big, sufficient to irrigate to 38,200ha of arable land.
Red river system: it includes Red River and two big branches: Lo River in the right hand side and Da River in the left hand side plus the two branches of Lo River: Chay River in Tuyen Quang Province and Day River in Vinh Phuc Province.
- Red River: Its section running through Vinh Phuc is from the confluence Bach Hac to the end of Trung Ha Commune, Yen Lac District with the length of more than 30km. Its average flow in a year is 3,860m3/sec, fourfold of that of Thao River, threefold of Lo River and twofold of Da River. The lowest flow in summer is 1,870m3/sec. The max flow is 18,000m3/sec. and average flow in the rainy season is 8,000m3/sec. Average water high level is 9.57m. The rise and the fall of water is irregular. In the rainy season, the water level can rise up to quickly, may be 3m high only in 24 hours. The crest of the flood is often 9m higher water level in dry season (in the historic food in 1971, it even reaches up 11.68m). In the dru season, Red River is a main source of the pumping stations in the both sides to supply water to their cultivation. Water from Red River contains big alluvium content, about 14kg/m3 with high quantity and many minerals. It is very the alluvium of Red River that has raised the level of the fertilized field of Vinh Phuc. At present, the River continues to raise the riverbanks and the field via the canals and irrigation systems.
- Lo River: It comes to Vinh Phuc teritory in Quang Yen Commune (Song Lo District) through Viet Xuan Commune (Vinh Tuong District) then meet Red River at the Bach Hac confluence. Its length is 34km. Its flow is 1,213m3/sec on an average in 1996. In rainy season, it can be 3,230m3/sec. The highest flow in 1996 is 6,560m3/sec. Its average high level is 6m (in 1971 is 11.7m). Its alluvium content is less than that of Red River. In the rainy season, the alluvium content is 2,310kg/m3. in dry season, its water is very clear, almost of no alluvium. Lo River is one of the sources to supply waater to Bach Hac pumping station.
- Day River: It is 41.5km long. It starts running through Vinh Phuc from Quang Son Commune (Lap Thach District) in the right side and Yen Duong Commune in the left side. It is a natural boundery of Lap Thach and Tam Dao Districts then it meets Lo River in Son Dong Commune (Lap Thach District) and Viet Xuan Commune (Vinh Tuong District). Its flow is 23m3/sec, its highest is 833m3/sec; in the dry season, it is only 4m3/sec. Day River has the same alluvium with Lo River (2.44kg/m3), but it the most important role of Day River is a water source of Lien So irregation system, 175km long, to security water to 14,000ha of rice field of districts: Tam Duong, Vinh Tuong, Tam Dao, Yen Lac, Binh Xuyen and Me Linh.
Ca Lo river system: This system includes Ca Lo River and its branches as Phan River, Cau Bon River, Ba Ha River and Cheo Meo stream.
- Ca Lo River is a branch of Red River. It separates out of Red River in Trung Ha Commune (Yen Lac District) and runs in between Binh Xuyen and Me Linh Ditricts with the length of 86km in a direction from Southwest to Northeast. It runs through Phuc Yen town and in the south of Kim Anh and Da Phuc districts, finally it meets Cau River in Luong Phuc hamlet, Viet Long Commune (Soc Son District, Ha Noi). The water source of this river is mainly from streams originating from Tam Dao range and Soc Son Mountain. Its average flow is only 30m3/sec. Its highest in rainy season is 286m3/sec. This river is as a reservoir to drain flood water in the rainy season. In the old section of this river, about 20km long, from Van Yen to Canh River was dammed up to make a large lake to irrigate and to raise fish.
- Phan River starts from Tam Dao range in Hoang Hoa Commune (Tam Duong District), Tam Quan Commune (Tam Dao District) runs through the communes of Duy Phien, Hoang Lau (Tam Duong District), Kim Xa, Yeen Lap, Lung Hoa, Tho Tang (Vinh Tuong District) in the direction of Northeast to Southwest. It turns to the direction of Southwest and Northeast passing by the communes of Te Lo, Đong Van, Đong Cuong (Yen Lac District) then discharging into Vac Lake (Vinh Yen City), through Quat Luu Commune to Huong Canh ( Binh Xuyen District), Son Loi Commune (Biinh Xuyen). Finaly, it flows into Ba Ha River and Ca Lo in Nam Viem Commune (Phuc Yen Town).
- Cau Bon River originates from Bac waterfall in Tam Dao Mountain and down to Ha hamlet, Ho Son Commune and joins into Xa Huong stream and Ban Long stream, Minh Quang Commune (Tam Dao District). It runs from North to South through the communes of Gia Khanh, Huong Son, Tam Hop then merging in Canh River in Tam Hop Commune (Binh Xuyen District). Phan and Cau Bon rivers make an arc with the two ends connect to Tam Dao Mountain. In the dry season, their water level is very low but in the rainy season, water from Tam Dao Mountain falls down largely, so it is often stagnant in Vac Lake causing flooded for Yen Lac and Binh Xuyen districts.
- Ba Ha River originates from Nhay Nhot stream of Trung My Commune (Binh Xuyen District) and Ngoc Thanh Commune (Phuc Yen Town). It runs in between Ba Hien and Son Loi communes and joins into Canh River then Ca Lo River.
- Cheo Meo Stream starts from Minh Tri Commune (Soc Son-Ha Noi), with 15km long, meets Ca Lo River in Nam Viem (Phuc Yen). In addition, Vinh Phuc has many big and small ponds and lakes. Among them are 94 lakes irrigating for 33,500 ha of cultivated land. The natural lakes are Vac Lake (Vinh Yen), Rung lake, Vuc Xanh lake, Quang Cu lake, Kien Cuong lake (Vinh Tuong) Tam Hong lake, Coc Lam lake (Yen Lac), Da Ngang lake, khuon lake, Souoi Sai lake (Song Lo), Rieu lake (Phuc Yen). The artificial lakes are Dai Lai (Phuc Yen), Xa Huong (Tam Dao), Lang Ha (Tam Dao), Van Truc (Lap Thach), Bo Lac (Song Lo).
5.2 Under ground hydrography
The feature of the layer contained water in Vinh Phuc
- Proterozoi layer is formed by the high-degraded rock, mainly is gonai schist, quartzit, amphibolit. The water of this layer is clear, high quantity but small flow. In some ruined and breaken zones, the flow can be 5l/sec. Water in this layer is very clear and good quantity used for refreshment.
- Mezoozoi layer is formed by the eruptive rock, middle and late Triat and Van Lang formation. Water of this layer may contain iron and small flow.
- Kainozoi layer is important layer but its flow is not large. When drilling 4-5m deep we can have water. In the ruined zone, water flow is very large, high quantity.
- Fault layer is formed by the faults, much water and good quantity.
Gernerally speaking, water is not equal in allocation, mainly concentates in the plain of the south province. Th underground water is very good quantity. However, in some locals where industrial parks constructed, water begins to comtaminate pollution and some criteria as iron, manganese are high, treatment is required now.
Underground water reserves in Vinh Phuc comprise the nnatural dynamic and static reserves. The natural static water reserve (water quality contains in the water layer) includes the elastic and static reserves. The elastic reserve only find in the the pleistocen layer in Vinh Phuc with total reserve estimated around 111.2 million cubi meters.
The natural dynamic reserve is a quantity running through section of water layer within a time unit. There are two zones to calculate it in Vinh Phuc, details are:
In the hill and mountain are mainly the fissured water layer, but this resever completely flows to the streams or rivers.
In the plain, there exisit some layers and only the Pleistocen layer contains much water and it palys an important impartant role in economic development.
With the hilland area of about 770km2, layers in Vinh Phuc has a quantity of 137,356m3/day of dynamic reserve.
With the plainland area of around 600km2, layers in Vinh Phuc has a quantity of 210,470m3/day of dynamic reserve.
Total dynamic reserve of Vinh Phuc is 347,826m3/day.
According to the database of water sourse of Vinh Phuc, the natural reserves (dynamic and static included) in the plain districts is 85.8 million cubic meters. That figure in the mountainous districts is 238,282m3/day. That figure in the plain districts is 276,910m3/day.
The underground water has been exploited for people’s daily living since long ago. At present, 80% of total households use the water from drilling or digging water wells.
The underground water in Vinh Phuc is exploited under two following systems:
- The concentrated system is the water supply works to hundreds to thousands of households. This water is treated by the advanced technology then supply via transmiaion pipelines to each household living in the urban, city, towns etc…Vinh Phuc now has two water plants (under Water Suppl and Environment Co., No. 1) with their capacity of 16,000m3/day fro 17 drilling wells of 12,000m3/day and 5 drilling wells of 3,154m3/day.
In addition, there are 35 works, 14 of these are under operation. They are in Thanh Lang, Huong Canh (Binh Xuyen); Son Đong, Van Truc, Quang Son (Lap Thach); Quang Yen (Song Lo); Bo Ly, Yen Duong, Đao Tru (Tam Đao); Yen Lac townlet (Yen Lac); Nam Viem Commune and Phuc Thang Ward (Phuc Yen).
- Small exploitation system is the exploitation by drilling or digging wells made by private family. They use hand pumps or electric pumps to have water from the wells. Almost of all the rural households, they use this system.
Besides the rural households, some industrial, services establishments, organizations also use this system for their daily operation. According to the data from the Vinh Phuc Department of Natural Resources and Environment, 9,405m3/day is exploited by them under this system, chiefly in Binh Xuyen, Vinh Tuong districts.
Quality of underground water differs from local to local, details as follows:
- In rural and industrial zonez (in Vinh Yen and in Phuc Yen), the indicators of pH, Cl, Zn, Mn, Fe are in the permitable limit or under such limit. It shows that the environment controls in these zones are better and better.
- In the rural and professional villages (in Vinh Tuong, Yen Lac, Tam Duong), the underground water gets a pollution signal and the pollution intends to increase according to the time.
Some polutted indicators exceeded, in 2004, the Viet Nam Norm (QCVN), such as that of Cu in Yen Lac, Mn in Yen Lac and Tam Duong, pH in Tam Duong, but these indicators proved to be decrease in 2006.
The problems are though the indicators in 2004 are permitable but till 2006, they turn out to be different, some indicators such as Zn, Cu in Tam Duong increase much higher.
It is notable that Cianua (CN0 is quite harzous substances discovered in three districts in 2004 but they are considerably reduced in 2006 in the underground water.
The underground water in Vinh Tuong, Yen Lac is acidy, pH is lower than that in QCVN 09:2008/BTNMT.
Although in the yearly observatory report of Vinh Phuc indicates that the quanlity of the underground water of Vinh Phuc is in good condions and it is not plolluted, but Vinh Phuc Department of Natural Resources and Environment warns the water should be regularly tested and the province should give instruction of usage and control reasonably the underground water.
In the urban localities as Vinh Yen and Phuc Yen, the wastes from people’s daily living and industrial wastes can affect the developed industry as Binh Xuyen, Tam Duong…the water. Therefore, the effective measures of control should be carried out.
In rural locals, because of the pipewater is not supplied, so the rural households can drill more water wells. If the drilling well is not controlled or no water in the drilled well but the backfilling is no good shall result from pollution of the water sources. More attention should be given to the professional villages, industrial clutsters, and the large-scale breedings.
Due to the characteristics of topography, climate and hydrography hence, Vinh Phuc has different categories of soil, including:
- The alluvial group: It has an area of 29,830.15ha, standing for 21.75% of total provincial land. It is mainly in districts: Lap Thach, Vinh Tuong, Yen Lac, Me Linh1 and Binh Xuyen. In the hollow zones, the alluvium is always in the flooded, so the clay is accumulated in the fastidious mood, the typical grey soil is formed.
- The sandy soil group: It has a course composition. Its grain size of above 70% is seen in every layer. The group is mainly formed by the deposition and accumulation of the washed substances from the mountains.
- The spotted soil group: It has an area of 11,887.3ha or 8.67% of total land. This group has a layer of under 25% of a young laterite with its thickness of above 15cm, its depth ranges from 0 to 50cm or even 125cm lying under the impoverished soil.
- The grey soil group: it has 42,435.27ha, or 30.9%. It contains the old alluvium with feralitic and soil in the mountainside.
- Th thin soil group: It has an area of 1,264.78ha and it belongs to the hill soil layer. Its thickness is under 30cm. Under ther layer is hard rocky layer or 10% of the fine soil in the depth of 0 to 75cm.
7. Forest minerals
According to the data by the Branch of Vinh Phuc Forest Management, total forest area of the province is 28,312.7ha and the covered forestry area occupies 22.4%, as of 31 December 2011.
The natural forest is 9,358.8ha or 32.81%, in which Tam Dao range is 6,978.3ha or 74.49%. This range has the Forest National Park. The Branch of Vinh Phuc Froestry Management controls and manages the most of the forestry area.
Besides, the province has an area of 18,953.9ha, or 67%, of the planted forest. Among this figure is 977.7ha of newly planted, accounting for 3.4%. Tam Dao has the largest planted froest, 28.34%. Next is Lap Thach (equivalent to 20.33%), Phuc Yen (19.01%), Song Lo District (16.78%). The lowest planted forset is Vinh Yen City, only 153.3ha or 0.007%. The households manage and own 9,161.8ha or 47.7% the planted forest. Vinh Phuc forest management agency only controls 3,899.2ha (20.33%). The state owned companies, or armed units or the economic entities control the remaining area.
Vinh Phuc has the forestry types as follows:
- Green foresttight, low mountain subtropical humidity forest: This type is in the height of 700m. This type occupies almost of the Tam Dao range with the high economic value such as choera chinensis, michelia Ital or cinnamomum ital. This flora community comprises many layers, sunshadetight with the large leaves and always green. This forest type is seriously damaged.
- Green foresttight, low mountain subtropical medium forest: It is in the height of above 800m (only seen in the West of Tam Dao range). The flora community here is dipterocarpaceae, lauraceae, fagceae, theaceae magnoliaceae or hamamelidaceae. In the height of above 1,000m, they are dacrycarpus, fokienia hodginsii, podocarpus neriifolius, and podorcarpus pilgeri or nageia fleuryi etc...
- The short forest in the peak mountain: This is a secondary one to the green foresttight, low mountain subtropical medium forest. This is formed on the top slope or on the peak of high, much sunshine and wind, and fogy mountain. Trees here are often short and slowed developed.
- The bamboo forest: This type is in between the other types of forest. Abve 800m is bamboo. From 500-800m is canebrake. Under 500m, there is neohouzeaua and other species of bamboo.
- The burnt over land forest: This type is in the buffer of Tam Dao National Park.
- The planted forest: This type includes the trees as pine, eucalyptus, acasia and large leaf tree in the height of 200 – 600m. The plated forest is in the Northwest of Lap Thach, Song Lo districts. In the hollow and valley areas in the South of the province, there is the agricultural palnts, subsidiary crops. In addition, there are bushes and grass field.
8. Flora and fauna
The floristic composition of Vinh Phuc is monsoon forest. Vinh Phuc has Tam Dao National Forest Park wher there are many species of flora, about 1,436 species of six botanical branches. Among these, there are 48 precious and rare species and 68 species in Viet Nam Red Book and the world. Based on the actual survey, we can divide Tam Dao flora into the category of grass, bush and wood trees in the soil mountain and rock mountain. Based on the value, this compositon can divide into groups: dipterocarpaceae, vegetables, decorative trees, wood trees, medicine plants,flour plants. The most ratio in this type is wood trees and medicine plants. In Tam Dao, there are some varieties the first time to be collected and described in Viet Nam.
The fauna in Tam Dao is very rich in species, including 1,141 species belonging to 150 families of 39 sets. Among them are 64 species of the scientific value needed to preserve, 16 edemic species, 18 species naemed in the worl red book and 8 species are banned from procurement.
There are 19 amphibian species, especially Tam Dao toadlike fish is one of the rare and precious specy that has been recorded in red book. The class of reptile has 46 species with big amount such as gecko, varan and lizard. The class of bird has 158 species, many of them are very specious: the white pheasant, grey peacock pheasant…The class of beast has 58 species. The bigger species are bear, tiger and panther. The smaller species are squirrel, cat, deer, mumtijac etc…. Some are high scientific value as musk deer, Rhinopithecus, Rhinopithecus bieti etc…
Among the fauna in Tam Da jungle, there are 47 rare and precious pecies, some of these are annihilated. Tam Dao National Forest Park is an untold value, is of great significance of environment protection and water supply source. It is also a location for scientific research, tourism, vacation and entertainment. In addition, it is a abundant source to supply wood and medicine plants. With the covered forest occupies to 90% of the forest area, Tam Dao Forest Park is said to be a reserve of gien of the rare and precious flora and fauna of the country.
The minerals in Vinh Phuc can classify following groups:
- Anttracite: it is in Dao Tru (Tam Dao) with its vein of 20m long, thickness ranges from 0.5 – 0.8m. Its content is about 1,000Mt and its calorry is from 7,000 to 8,000 kcal.
- Lignite: It is in Bach Luu and Dong Thinh Communes. In Bach Luu, its vein is 0.8m, 10m thick. This vein is not investigated and evaluated. In Dong Thinh, its vein is 0.4 – 0.5m. It is 5-7m deep below. The layer covered on this vein is agglomerate clay and agglomerate flour. Its content is some hundreds MT. Its calory is 6,000 – 8,000 kcal.
- Peat: there are a lot of this coal in Vinh Phuc. The two bigger locations are Van Quan (Lap Thach) and Hoang Lau (Tam Duong).
In Van Quan, its content is around hundreds of thousands cubic meters. This coal can be used as the fertilizer and fuel.
In Hoang Lau, it is in dozens of hectares of swamp and hollow rice field. Its thickness is 1 – 2m, some places even to 3m thick. It is 0.5 – 1m deep below the covered layer. Its content is about 500,000m3. The layer contains this peat is sand clay and flour of the Fourth Sediment Hanoi and undisintergrated wood Humit.
- Barite. It is under thr rolling form, originated from thermal capacity, mixng with lead, zink. It comprises three veins in Dao Tru (Tam Dao).
Vinh Ninh vein: it is 10m long, 0.2-0.3m thick. It included mainly galen, xphalerite mixed with barite and quarzt.
Suoi Son vein: It is 40m long, 0.5 – 1m wide. It is interrupted vein. Its ore is galen, limolite and barite. Its surrounding is serinite and acgilite rocks.
Tan Lap Hamlet vein: It is 30m-50m long, 0.5-1m wide.
- Copper: It is newly discovered. Its poor ore is chancopyrite mixed with pirite and pirotine. It exists in Suoi Son, Dong Gieng (Dao Tru), Dong Bua (Tam Quan) Hop Chau, Ban Long and Minh Quang communes of Tam Dao District.
- Gold: There are many quartz veins in the fault of Southwest Tam Dao, which defined as the same age with the golden mineralization and the dispered belts of golden mineral sand in Dao Tru, Minh Quang (Tam Dao), Thanh Lanh (Binh Xuyen) Thanh Loc (Phuc Yen).
- Tin. It is in the mineral sand in Gieng hamlet (Dao Tru), Den Ca stream (Dai Dinh). The geologists estimate that in Tam Dao Mountain, there is a rich wood-fiber Tin, but not discovered.
- Iron: There are two main veins: Ban Gian vein in Lap Thach, the mineral contains iron os manhetite with 200m long, 50m wide. The upper layer is iron cap and laterite. People here exploit it to make laterite brick. Mahetite here is a magnetic iron, so it is used to produce magnetism.
Khai Quang iron vein (Vinh Yen) starts from Dao Tu Commune, Thanh Van Commune (Tam Duong) through Dinh Trung to Khai Quang (Vinh Yen) with tens km long, tens meters wide even hundreds meters.
This vein is also newly investigated and discovered. Main composition of this iron vein is hematite, manhetite. Its surface layer changed into limonite and gotite. Its content is 40-50%.
Besides the two above-said locations, there is another more Dong Rua spot (Tam Dao). This location should be specific research to discover it.
Non-metal mineral group
In Vinh Phuc, there is non-metal mineral group. It is mainly Kaolin originated from the weathered alumoxilicate rock, including granite, plagio granite rock allocated in Tam Duong, Vinh Yen and Lap Thach. Dinh Trung kaolin mine (Vinh Yen) has an area of 5.5km2 including two types:
- Kaolin originated from the weathered granite with its reserve is 6 million MT. The other locations have the same this type of kaolin in Thanh Van, Huong Dao, Hoang Hoa communes (Tam Duong), and Yen Duong (Tam Dao) but they are not assessed.
- Kaolin originated from the pecmatite, sienite alkali vein that is completely weathered from Fespar rock. It is in Dinh Trung mine, Moi hamlet Thanh Van and in some hamlets of Lai Son (Dong Tam ward) and Kim Long Commune (Tam Duong).
Construction material group
- Clay for making tile: It allocates in most of area of the plain and mountain regions.
- Clay in the plain region: It originated from the sediment of river, sea and lake. This layer is 1-10m thick, hundreds of square kilometers wide with the content of billions of cubic meters. The reserve of only three mines: Vac Lake (Vinh Yen), Quat Luu and Ba Hien (Binh Xuyen) is tens of million cubic meters.
- Clay in the hill region: It originated from the non-completely weathered alumisilicate rock, so its frain is not high fine, notbig spongy and less ductile. This clay layer is 1-5m thick. Its color is brownish, so it is used to make tile, but this tile is not spongy but brittle, much fuel to burn. The hill-made bricks only occupy 1-3%.
- Black grey and brown grey: This is in Xuan Hoa mine (Lap Thach). It is weathered from the schrist-aged Devon. When it is burned upto 900-1,000 0C, the water vaporized making the spongy holes. This is called Kezanzite to be used to produce light concrete fro construction of the works set up on the weak ground. It is good in anti-heat, anti-sound. Xuan Hoa mine has its reserve of millions of cubic meters.
- Sand and pebble in the river and in the terrace: Sand and pebble from Lo River, Day River belong to quartz sand, silic, so it is high hardness, good linkage with limb and cement. Lo River has its reserve of 30 million cubic meters of sand and pebble. Every year, millions of cubic meters of sand add to the reserve. The sand and pebble in the terrace, level 2-3 in Xuan Loo, Van Quan, TRieu De (Lap Thach), Cao Phong, (Song Lo0, Hoang Dan (Tam Duong) from Day River has the reserve of tens of million cubic meters.
- Construction rock: They are stone, free-stone, macadm with their quantity of millions of cubic meters. These stone concentrate in Tam Dao Maountain.
At present, there are three rock mines in the province, inclding Tan Trung stone mine (Lap Thach), Da Coc mine in Minh Quang Commune (Tam Dao) and Trung Mau mine (Binh Xuyen). These mines supply hundreds of thousand tons of construction stone.
-Stone for engravement, embankment: In Bach Luu, Hai Luu (Song Lo) there is the agglomerate sand rock with its medium and small grain, agglomerate flour of macno type. Thanks to its characteristics, Hai Luu Commune becomes the professional village specializing in engraving stone to have products such as mortar or fine arts such as stone statue, stone tablet. The stone in block or smaller are used to embank dyke, road.
10. Characteristics of natural geography
Based on the characteristics of the natural geography, Vinh Phuc can be diveided into three different natural geographic zonez as follows:
- The mountain zone: Tam Dao, Song Lo and Lap Thach.
- The inland zone: Binh Xuyen, Vinh Yn, Phuc Yen and Tam Duong, and
- The plain zone: Vinh Tuong and Yen Lac.
10.1 The mountain zone of Tam Dao, Song Lo and Lap Thach
This natural geographic zone is divided into two distinct mountain zones: Tam Dao zone and Song Lo, lap Thach zone in the Northwest of the province.
Tam Dao range is at the end of the bow-shaped range of the upper reaches of Chay River. Its tail almost huddles in Tam Dao. Its North stretches out as the blade of fan and its height gets down and down to change into hill land and northern delta. Tam Dao Mountain range is in three provinces: Tuyen Quang, Thai Nguyen and Vinh Phuc with 60km long, 15km wide. In Vinh Phuc teritory, Tam Dao range is in the Southwest of the province, starting from Dao Tru Commune-its Northern peak. Its East is cut by the divide separating two provinces: Vinh Phuc and Thai Nguyen.
Tam Dao range goes in the direction of Northwest - Southeast. Its top is acute; its side is slopping and short. Its slope level is medium from 20 - 250m; some points are above 350m hight. There are 20 peaks on the whole range. Tam Dao range serves as a screen for preventing the plain zone from whirlwind. The highest peak, 1,592m high, is the peak in Giua Mountain (Dao Tru) in the North. The three famous peaks on Tam Dao range are Thach Ban (1,388m), Thien Thi (1,357m) and Phu Nghia (1,300m). The deep partition is big and thick because the secondary clash is almost perpendicular to the main clash. The valley of the streams and the rivers fall into Day River.
Tam Dao range has four main types of topography:
- The valley in between the mountain zone and the plain zone along the rivers, streams with their height being less than 100m; slope is under 70. The topography is underfoot of the mountain, stream’s, and river’s bank.
- The high hill: its height is 100-400m; its slope is 10-150.
- The low hill: its height is 400-700m; its slope is above 250, and
- The medium hill: Its height is 700-1,592m; its slope is 250. This is mainly in the highest of the mountain, on the peaks and the sharp, acute, full of obstacles, and difficult of access.
The mounatin zone in Song Lo, Lap Thach districts: This is formed by magma rock belonging to Chay River complex with the age of Paleozoi-the aerly Devon, including the medium to large grain granite rock under the form of blackish porphyr; granite muscovite of medium and small grain size; granite 2 mica under the form of gneiss and the veins of aplite and pegmatite. The features of this rock are rich in aluminum and alkali. In the Chay complex, there are veins of the weathered kaolin from aplite granite and pegmatite which are usefull to the pottery and porcelain industry of the province. In addition, there is Thet Mountain, 335m high, in the West following to the Northwest-Southeast. This mountain aged the aerly Paleozzoi of Na Duong formation. This mountain is separated from the mountain with Pleozoi age by the fault in the Northwest - Southeast direction. In its East, it has Mesoproterozoi age under Chay River complex. This is a low hill zone in the Northwest of the province with its height of 100-633m. The highest peak is 633 m (Sang mountain peak). From 200m upward, its slope is very big, from 15 to 200, even some locations reach 250, which create the low valley, but high slope. The topography is eroded, separated, many rivulet brooks. With the height of less than 200m are hills, soil hillocks with the gentle slope, which are good fro plantation or cultivation. The mountain zones of Tam Dao and Song Lo, Lap Thach is in the monsoon climate. The rainfall here is high (Tam Dao: 2,600mm). The rainy season lasts from April to October, occupying nearly 90% of the yearly rainfall. Much rain months are June, July, August and September; the highest is August. The rainy days are above 140 days/year. The mean temperature in he mountain zone is 19 -200C. Other places are higher ranging from 20-230C. The coldest month is January (110C - 150C); the hottest month is July (26-280C). The temperature on the mountain peaks is lower, about 18-190C. In January, it can be falen to 1-80C; the highest is June, about 230C. The climate in Tam Dao is mild all the yera round. It is quite good condition for tourist development. The climate in the sub-regions of the Northeast area as follows: average humidity is 84-85% in the rainy season, but in the finerain days, the humidity can reach 90%. In the dry season, the humidity is low, 70-75%. It is because of much rain, so the rainwater falls from the mountain to the mountain foot then flows into the streams and rivers very quickly. The streams and rivers there are short, slope and the centipede-foot shaped branches, finally the water flows to lakes, pond of Day River basin, which create two distinct seasons in the zone: the flooded season (August) and dry season (February). This zone has many lakes with large ans small sizes; the largest lakes are Van Truc, Bo Lac, Suoi Sai, Da Ngang and others.
The land of this zone is mainly grey soil, including the shallow grey humus in a height of above 700m; the shallow brownish grey in the height of less then 700m; a small amount of acidy motleycolorerd soil in valley of Ba Ha. Along Ca Lo River bank, there is typical grey soil and mostleycolored grey soil. Alonh the streams, faults, there is acidy sand and acidy alluvial soil. In the South has the shallow brownish grey soil. In the West, it has the typical deep grey soil.
10.2 The Inland region: Binh Xuyen, Vinh Yen, Phuc Yen and Tam Duong
This region lies on the high-degraded foundation spreading under the direction of Northwest-Southeast. This contains Gnei rock rich plagioclas, biotite having the middle Proterozoi age; in some locations, there are quartz contained mica. In the West of the mountain zone, there are hills with the early Neogen (N1), Na Dương formation. In addition, the Fourth sediment, the medium-upper Pleistocen age and Holocen age form most of the area of this region. The hill zone has the height of 20-238m; average slope is less than 200, and above 200 is the hill in the Northeast. The hills go in the direction of Northwest to Southeast. The other hills exist under the blocks with their pediment surface of 20-60m high; slope is grade III (8-150). Along the streams and rivers, there is an additional river sediment grade 1 and the surface of the plain accumulates in low layer in between low hill zone. The lower is the alluvial stretch with its slop less than 30. In the East of the region, there exists high hill topography. It is on the extension of Tam Dao range, medium Triat age, Na Khuat and Hien River formation.
Cimate in this zone is a monsoon type. Southeast wind comes from April to September; Northwest wind comes from October to March the following year. There are two distinct seasons: Hot and humid season, much rain (April to September); cold and dry season (October to March next year). The average yearly temperature is around 23-240C. The coldest month in a year is January (16.70C) and the hottest month is July (30.20C). The average yearly rainfall is 1,166.6mm. The least rain month is November-December with 9.0 -9.5mm; the most rain month is August with 236.0mm. The average humidity is 78-80%. The lowest humid month is February (72%); the highest is August.
The hydrographic system is dense with a lot of rivers, streams and lakes. The biggest system is Day River system where water is to supply to the fields of Tam Duong, Binh Xuyen districts. However, it is dense but many rivers and streams originate from Tam Dao Mountain running on the sloppy land causing the weak drainage in rainy season, flooded occurred sometimes. The lake system is the reservoir to supply water for agricultural cultivation in the dry season. The biggest lakes are Vac Lake (Vinh Yen), Dai Lai Lake (in the East). Vac Lake has 250ha of the water surface in the dry season. In the flooded season, it is 500ha. Dai Lai Lake is the biggest artificial lake in the region. Its useful capacity is 25.4 million cubic waters, enough to supply to 2,700ha of cultivated area. Dai Lai lake is also a excellent location for tourists to enjoy vacation and entertainment. This lake has a system of canal and pumping stations with respect of irrigation fro the locality.
It is because of development on the gnei rock rich of plagioclas, biotite, silimanite, so its soil is mainly grey, including the typical grey and reddish, brownish grey soil. The untypical alluvial soil locates along Day and Ca Lo riverbanks. Along Day River bank, there is a small strip of alluvial soil with neutral acid, gets flooded in the rainy season. In addition, there is thin layer soil on the high hill of Xuan Hoa Ward (Phuc Yen). On its surface, it is weathered soil, such as the brownish clay, laterite and iron cap.
The main flora here are the planted forest (scattered allover the zone), fruit trees (litchee, longan etc....); the short-term industrial trees (bean, underground nut). In the lower land, there are the food trees.
10.3 The Plain zone in Vinh Tuong and Yen Lac
Most of the area is on the river dediment of mid and upper Holocen age. In the East and Southeast, it is the sediment of the sea with Pleistocen; the sediment of lake with Pleistocen and some omitted blocks has the Neogen age of Na Duong formation.
This is a flat country along the river with the height is less than 30m. the Red River zone has its slope less than 50.
The temperature in the zone is like that in Northen Delta. The mean temperature is around 230C. The highest temperature month is July (280C); the lowest is January (160C). there is much fine rain in January and February. The average rainfall is 1,500 - 2,000mm.
It is because of low topography, this zone often gets flooded, creating many lakes. Lien Son canal system runs through seven districts, from the mountainous, inland and plain zone (Lap Thach, Song Lo, Tam Duong, Binh Xuyen, Yen Lac, Vinh Tuong, Me Linh - Ha Noi). Ca Lo River is 86km long, originates from Van Yen Commune running in the direction of Northeast-Southwest in between Binh Xuyen and Me Linh district (now Me Linh is in Ha Noi). The water source of this River comes from the streams from Tam Dao and Soc Son mountains. Its flow is about 30m3/sec. The highest flow in the rainy season is 286m3/sec. This system drains water in the flooded season. Rung Lake is in the three communes: Tam Phuc, Tu Trung and Ngu Kien (Vinh Tuong) having a water surface area of 205ha. In the rainy season, it can reach to 500ha. This lake is a water source for supplying water to the rice filds of the localities aand aquatic raising.
The soil of this zone is mainly the less neutral acidy alluvium, including the untypical less neutral alluvial, shallow and deep neutral alluvial grey, shallow and deep neutral alluvial and motleycolored grey, and agglomerated neutral alluvial soil. Coming from the river into the inland, the strip of acidy alluvium is behind the less acidy neutral alluvium. In the Southeast is the motleycolored strip, mixed with grey soil, with rather large area.
The flora of this zone: it is mainly the short-term agricultural plants and food trees. In addition, people in this zone transplant flour and medicine plants. The people living inland of the dyke often transplant rice, one to two crops. The outside grow the subsidiary crop.
Based on the characteristics of natural conditions, splitted topography, structure of geographical layers, pedology, climate condition and hydrography, Vinh Phuc is divided into three geological zones with its own feature. The mountainous zone in Tam Dao, Song Lo, lap Thach with mild climate shall be great potential for development of tourism, household economy and farm. The inland zone: Binh Xuyen, Vinh Yen, Phuc Yen and Tam Duong, shall be the address for development of industry and agriculture. The plain zone, Vinh Tuong and Yen Lac, shall take the advantage to develop the industrial park, commodity agriculture. This zone also has advantage of development agriculture, professional village and handcraft.
(Source: Vinh Phuc monography- Social Science Publishing House Hanoi 2012)