Skip navigation links
Overview Lam Dong
Geography
Archeological Relics
Languages
Habits and customs
Literature And Arts
Architecture
Lam Dong Map
News - Event
The highlight news
International news
Local news
Planning - development
Da Lat City
History and Development
Nature
Population
Agriculture
Forestry
Tourism
Service
Industry and Handicraft
Traffic
Power
Water Supply And Sewerage System
Alexandre Yersin
sadfasHome > Overview Lam Dong > Geography
Geography 

Lam Dong is a mountainous province located in South Central Highland Region, between geographic coordinates:

X = 11012 '- 12015' northern latitude

Y = 107015 '- 108045' E ° eastern longitude.

The area of Lam Dong province is 9764.8 km2, about 2.9% area of the nation. Lam Dong borders Khanh Hoa and Ninh Thuan provinces to the east Binh Phuoc province to the west, Dong Nai province to the southwest, Binh Thuan province to the south - southeast, Dak Lak province to the north.

The boundary lines of Lam Dong province: Da Dang river, Krong Kno in the north, across the east of Bi Dup mountain, Kanan mountain, Yang Kuet mountain in the east; Yam, Marong, Dronang mountains in the south and Dong Nai river in the west.

Lam Dong is located entirely in the inland of Vietnam, without national border and national shoreline

I. Geographic Name and Administrative Border During The Periods

1. The Periods before The Year Of 1899

According to the maps in "Dai Nam nhat thong chi" issued by Nguyen dynasty, most present land in Lam Dong province belonged to Binh Thuan province and Ninh Thuan area.

There were 20 hamlets in this province as stated in "Di Dinh tho phu" Section:

1. “1. Phi ba Nam

2. Bang Dung

3. Giang Trang

4. Phi Chan

5. Phi Lo

6. Bang Trang

7. Tam Bach

8. Tham Luat

9. Ban Tau

10.La Mien

11. Nam luan

12. Giang Tre

13. Bang Bi Thuy

14. Bang Bi Hoa

15. Luu Mien

16. Bang Trinh

17. Nang Duy

18. Phi Co

19. Chan Dung

20. Phi Chinh”

The book wrote about a river: Tây hữu Dã Dương giang bất thâm nhi quảng, trung đa ngạc ngư (meaning : There is Da Duong river in the west, it’s not deep but wide and has a lot of crocodiles here).

The book also wrote about the living activities of people along the two rivesides. The trading of Chinese sometimes took place in the south of river. There were few people in the north of river. In the 19th year of Tu Duc reign, the court appointed their subordinates to explore but the Thuong people feared to guide and the exploration was failed.

2. Periods of 1899 – 1945

The Decision of establishment Dong Nai Thuong province and two administrative stations (Post administrative) in Tanh Linh and Lang Bian highland was signed on 01st November, 1899 by Governor General Paul Doumer.

Dong Nai Thuong province included: Dong Nai river upstream which border with Cochinchine and Cambodia, its township was Djiring.

In the 17th of Thanh Thai reign (1905), Dong Nai Thuong province was abrogated and again directly under Binh Thuan province.

The Decision of establishment Lang Bian province was signed on 06th January, 1916 by Governor General E. Roume including the entire mountainous areas of provinces: Ninh Thuan, Binh Thuan, Dong Nai, Binh Phuoc now.

The boundary lines of Lang Bian province: Krong Kno river in the north, Krong Pha river in the south east (now belongs to Ninh Thuan province), Ca Giai river – a branch of Phan Ri river (now belongs to Binh Thuan province) in the south, Cambodian border in the west.

The Edict of establishment Da Lat centre (centre urban) in Lang Bian was issued on 20th April, 1916 by the Regent Council of Duy Tan King.

The Edict was signed on 20th April, 1916 and the Decision of Da Lat center establishment was signed by French Resident Superior J.E. Charles on 30th May, 1916.

An Edict was signed on 11th October and the Decision of Da Lat town establishment was signed by General Governor Long on 31st October, 1920.

Da Lat town was a secondary town including its city and suburb. Its suburb included villages and lands of Lang Bian highland.

The remaining of Lang Bian province was named Dong Nai Thuong province.

The Decision of Lang Bian reestablishment was signed On 8th January, 1941 by General Governor Decoux, also the Mayor of Da Lat and the Governor of Lang Bian province.

3. Periods of 1945 – 1954

In August of 1945, Provisional Revolutionary People’s Committee and Viet Minh Font of Lam Vien province and Dong Nai Thuong were founded.

The Decision of Mergence Lam Vien and Dong Nai Thuong province into Lam Dong province was signed on 14th December, 1950 by the Chairman of Centre South administrative resistance Committee Nguyen Duy Trinh.

The Decision No. 73-TTg of unifying Lam Vien province and Dong Nai Thuong province to Lam Dong province was signed on 22nd February, 1951 by Vice Minister of Vietnam Democratic Republic Pham Van Dong.

The Edict No. 4-QT/TD for defining the border of Da Lat town was signed on 10th November, 1950, by Bao Dai King.

The boundary line between Da Lat town and Dong Nai Thuong province: the north from the north east of O”Neil plantation to Lam Vien rotary; the east across Labbe Nam mountain; the south from 1586 peak to co-ordinate 117gr8804 east longitude, 13gr2034 north latitude; the west from western Cam Ly airport.

According to Dia phuong chi Da Lat (Da Lat Monography), Da Lat town was the centre of Hoang Trieu Cuong tho with 67mk2 area and population of 25,041 people.

4. Periods 1954 – 1975

Dong Nai Thuong Province

Dong Nai Thuong province was established in 1899, abrogated in 1905 and reestablished in 1920.

Dong Nai Thuong province bordered by Darlac to the north, Khanh Hoa and Ninh Thuan province to the east, Binh Thuan province to the south and Bien Hoa province to the west.

In 1956, the area of Dong Nai Thuong was 10,650 km2 with the population of 46,599 people. Djiring was its township.

The province had three districts: Djiring, B'Lao and Dran - Fyan. B'Lao district had 159 villages, Djiring district:188 villages; Dran – Fyan district: 274 villages.

Lam Dong Province

On 19th May, 1958, the Decision No. 170-NV of renaming Dong Nai Thuong to Lam Dong province was signed by President Ngo Dinh Diem.

Its township was moved down from Djiring to B’Lao on 30th November, 1958. B’Lao was changed into Bao Loc on 19th February, 1959. B’Sar commune of Tanh Linh distric, Binh Tuy province was merged to Bao Loc district on 12th July, 1965.

Lam Dong Province bordered with Quang Duc province in the north, Tuyen Duc province and Binh Thuan province in the east, Binh Thuan province and Binh Tuy province in the south, Phuoc Long province and Long Khanh province in the west.

The boundary lines of Lam Dong province: the north was Da Dang river, the east were: Da Trong river, Da K’Nang, Da Nhim river; the west was Da Lay and Dong Nai river.

In 1972, the area of Lam Dong province was 5,503 km2 with the population of 90,157 people. Bao Loc was its township.

Lam Dong province had two districts: Bao Loc and Di Linh; 23 communes and 88 hamlets.

Bao Loc District

(District capital: Bao Loc; 12 communes)

1. Thien lac

2. Quan Lac

3. Chau Lac

4. An Lac

5. Tan Lac

6. Tan Thanh

7. Tan Phat

8. B’ Sar

9. Madagouil

10. Tan Don

11. Tan Phu

12. Tan Rai

Di Linh District

(District capital: Di Linh; 11 communes)

1. Di Linh

2. Dai Hiep

3. Lien Dam

4. Tan Dan

5. Chau Trung

6. Bao Thuan

7. Đinh Lac

8. Dang Gia

9. Gung Re

10. Đinh Trang Thuong

11. Đinh Trang Ha

Tuyen Duc Province

On the day of May 19th, 1958, Ngo Dinh Diem issued the Degree No 261-NV to establish Tuyen Duc province.

On June 30th, 1958, Dran district was separated from Lam Dong province and intergrated to Tuyen Duc province.

Tuyen Duc province bordered with Darlac province to the north, Ninh Thuan and Khanh Hoa provinceôt the east, Ninh Thuan to the south, Lam Dong to the west, Quang Duc province to the north-west..

In the north, the boundary lines of Tuyen Duc cross into the south of Chu Yang Sin mountain; the east was near with Bi Dup mountain; with head of Ngoan Muc mountain pass in the south-east, The west was Da Nhim, Da K’Nang, Da Trong river.

In 1958, Tuyen Duc province had the area of: 5.067 km2, population of: 49.025 people. District capital is in Da Lat.

Tuyen Duc Province had 3 districts: Don Duong, Duc Trong and Lac Duong.

Don Duong District

(District capital city: Don Duong; 6 communes)

- Xuan Lac region consists of communes: Lac Nghiep, Xuan Truong;

- Lac My region consists of communes: Lac Lam, Thanh My;

- Linh Nhan region consists of communes: Kill Plagnol Thuong, Linh Gia.

Duc Trong District

(District capital city: Tung Nghia; 12 communes)

- Ninh Thanh region consists of communes: Hiep Thanh, Phu Ninh, Tung Nghia;

- Son Binh region consists of communes: Phu Son, Binh Thanh;

- My Le region consists of communes: Teurlang Deung, Teurlang Tho, Romène, Yenglé;

- Đinh Tan consists of communes: N’Thol Ha, Lang Bian, Dinh Van.

Lac Duong district

(District capital city: Binh Ninh (B’Neur ); 7 communes)

- Phuoc Tho region consists of communes: Xuan Tho, Phuoc Thanh, Thai Phien;

- Da Ta region consists of communes: Dakao, N’Thol Thuong;

- Nhan Lac consists of communes: Kill Plagnol Ha, Lat.

5. Periods Of 1975 - 2000

In November of 1975, La Duong district was disintegrated, and the communes of Lower Kilplagnol, Xuan Truong, Xuan Tho were integrated to Don Duong district; Lat and Da M’rong communes to Duc Trong district.

According to Decision dated September 20th, 1975 issued by Politburo, Ha Noi, Hai, Sai Gon, Hai Phong and Da Lat were 4 cities under central; 4 provinces: Lam Dong, Tuyen Duc, Binh Thuan, Ninh Thuan were formed a new province.

Then, zone party committee of No 4 zone arranged a meeting and decided to name the new province to be Thuan Lam, township was in Phan Rang.

On December 20th, 1975, Politburo decided to adjust the incorporation of some provinces from No VI zone back to become new provinces.

On February 1976, The Provisional Revolutionary Government of the Republic of South Vietnam issued the Decree about disintegrating zone, integrating provinces in the south of Viet Nam.

According to this Decree, Lam Dong province, Tuyen Duc province and Da Lat city were intergrated and formed Lam Dong province.

On March 14th, 1979, Council of governments issued the Decision No 116-CP to devide some districts of Lam Dong Province:

Splited Bao Loc district into two districts and named Bao Loc and Da Huoai;

Splited Don Duong district into 2 districts : Don Duong and Lac Duong District.

After splitting above districts, Lam Dong included 6 district, 1 city, 61 communes, 5 town and 6 wards:

1. Bao Loc District has communes: Loc Lam, Loc Nam, Loc Thang, Loc An, Loc Thanh, Loc Son, Loc Tien, Loc Bac, Loc Ngai, Loc Thanh, Loc Nga, Loc Phat, Loc Chau, Loc Tan and Bao Loc (B’Lao) townlet.

2. Da Huoai District has communes : Ma Da Goui, Da Oai, Da M’ri, Da Ploa, Da Teh, Da Ko, Da Lay and townlets : Ma Đa Goui, Da Teh Farm, Da M’ré Farm.

3. La Duong has commune: Lower Kilplagnol, Lat, Da M’rong, Da Tong, Da Long.

4. Don Duong District has communes: Tu Tra, K’Dơn, Thanh My, Ka Do, Lac Xuan, Lac Nghiep, Lac Lam, Loan and Don Duong townlet.

5. Duc Trong District has communes: Hiep Thanh, Lien Hiep, Tung Nghia, Phu Hoi, Binh Thanh, Phu Son, Dinh Van, Tan Hoi, Da Don, N’Thol Ha, Phi To và Tan Van.

6. Di Linh District has communes : Di Linh, Ninh Gia, Đinh Lac, Tan Chau, Son Đien, Gung Re, Dinh Trang Thuong, Dinh Trang Hoa, Tan Thuong, Hoa Bac, Gia Hiep và Lien Dam.

7. Da Lat City has 6 wards and 3 communes : Ta Nung, Xuan Truong, Xuan Tho.

On september 19th, 1981, converted Di Linh commune into Di Linh town; established Bao Thuan commune; new industry zone of Ha Noi in Lam Dong.

On December 29th, 1981, The Seventh National Assembly issued the decision to intergrate Dong Nai commune(19.000 ha) of Phuoc Long district, Song Be province into Da Huoai distric, Lam Dong province.

On March 28th, 1983, splited Loc Ngai commune of Bao Loc district into Loc Ngai and Loc Duc commune, splited Loan commune of Don Duong district into Ninh Laoan và xã Da Loan.

On March 6th, 1984, Council of Ministers issued the Decision No 38-HĐBT to disintegrate Nghia Tung commune to establish Lien Nghia town in Duc Trong and split communes.

Table 2 : READJUST COMMUNES AND TOWNS

District

Former Commune

New Commune

Di Linh

Gia Hiep

Son Đien

Dinh Trang Hoa

Gia Hiep, Tam Bo

Son Đien, Gia Bac

Dinh Trang Hoa, Hoa Trung

Da Huoai

Da Ko

Da Tẻh

Dong Nai

Do Ko, Trieu Hai

An Nhon, Ha Dong

Dong Nai, Quang Ngai, Phu My, Phuoc Cat

Lac Duong

Kil Pla Gnol

Da Chais, Da Sa

On June 6th, 1986, Council of Ministers issued the Decision No 67-HĐBT to readjust the Administrative border of communes, wards, towns of Lam Dong (Table 3)

Table 3: READJUST THE ADMINISTRATIVE BORDER

Distict, City

Former Commune

New Commune, Townlet

Da Huoai

Da P’loa

Da P’loa, Doan Ket

Da M’ri

Da M’ri, Ha Lam, Da M’ri Town

Da Oai

Da Oai, Da Ton

Trieu Hai

Trieu Hai, Quang Tri

Ha Dong

Ha Dong, My Duc, Quoc Oai

Da Lay

Da Lay, Huong Lam

Quang Ngai

Quang Ngai, Tu Nghia

Phu My

Phu My, My Lam

Dong Nai

Duc Pho, Nam Ninh, Gia Vien, Tien Hoang, Dong Nai town

Phuoc Cat

Phuoc Cat 1, Phuoc Cat 2

Don Duong

Da Loan

Da Loan, Ta Nang

Ninh Loan

Ninh Loan, Ta Hine

Di Linh

Đinh Trang Hoa

Đinh Trang Hoa, Hoa Ninh, Hoa Nam

Da Lat

6 wards

12 wards

On June 6th, 1986, Council of Ministers issued the Decision No 68-HĐBT to splite Da Huoai district in to 3 districts: Da Huoai, Da Tẻh, Cat Tiên.

Da Huoai district has 2 towns: Madagui, Da M’ri and 7 communes: Da P’lơa, Doan Ket, Da M’ri, Ha Lam, Madagui, Da Oai, Da Ton.

Da Tẻh has Da Tẻh townlet and 9 communes: Da Kho, Trieu Hai, Quang Tri, Ha Đong, My Đuc, Quoc Oai, An Nhon, Da Lay, Huong Lam.

Cat Tien district has Dong Nai townlet and 10 communes: Quang Ngai, Tu Nghia, My Lam, Phu My, Duc Pho, Nam Ninh, Gia Vien, Tien Hoang, Phuoc Cat 1, Phuoc Cat 2.

On October 24th, 1987, Council of Ministers issued the Decision No 157-HĐBT:

Integrated Ha Noi new industry zone into Duc Trong District.

Disintegrated Ninh Gia commune of Di Linh district; spited 4 communes: Da Loan, Ninh Loan, Ta Hine and Ta Nang of Don Duong District to integrate into Duc Trong District.

Disintegrated Thanh My commune to establish Thanh My town.

Established 10 commune of Duc Trong District: Ro Men, Lieng Sronh, Phi Lieng, Phuc Tho, Tan Thanh, Hoai Duc, Dan Phuong, Tan Ha, Gia Lam, Dong Thanh. Splited Nam Ban town of Duc Trong district into 2 administrative units and named: Nam Ban town and Me Linh commune.

Disintegrated Dinh Van commune of Duc Trong district to establish Dinh Van town of Lam Ha district.

Spited Duc Trong district into 2 districts and named: Duc Trong and Lam Ha District.

Duc Trong district has Lien Nghia town and 11 communes: Da Loan, Binh Thanh, Phu Hoi, Lien Hiep, Ninh Gia, Ninh Loan, N’Thon Ha, Ta Hine, Ta Nang, Hiep Thanh, Tan Hoi.

Lam Ha district has 2 townlets: Nam Ban, Đinh Van and 15 communes: Da Don, Phi To, Phu Son, Tan Van, Phi Lieng, Ro Men, Lieng Sronh, Phuc Tho, Tan Thanh, Hoai Đuc, Dan Phuong, Tan Ha, Gia Lam, Dong Thanh, Me Linh.

On September 15th, 1989, integrated Lac Nghiep commune to establish Dran town of Don Duong district.

On July 11th, 1994, Government issued the Decision No 65-CP to split Bao Loc district into Bao Loc town and Bao Lam district.

Bao Loc town has 6 wards: 1, 2, B’Lao, Loc Son, Loc Phat, Loc Tien and 4 communes: Loc Chau, Dam Bri, Loc Thanh and Loc Nga.

Bao Lam district has Loc Thang townlet and 11 commune: Loc Quang, Loc Ngai, Loc Duc, Loc Lam, Loc Phu, Loc Bac, Loc Bao, Loc An, Loc Tan, Loc Thanh and Loc Nam.

Pursuant to Decision No 761 TTg dated November 22nd, 1995, Lam Dong province delivered 34.000 ha of land in the north of Krong Kno river to Dac Lac province.

Pursuant to Decree No 38/1999/NĐ-CP dated June 18th, 1999, 4 new communes were established: Hiep An (of Duc Trong district), Lien Ha (of Lam Ha district), Tan Nghia (of Di Linh district), Dai Lao (of Bao Loc town).

Pursuant to Decree No 79/1999/NĐ-CP dated August 24th, 1999, 3 new communes were established: Dung K’No (of Lac Duong district), Da K’Nang (of Lam Ha), Tan Lac (of Bao Lam).

Pursuant to Decree No 62/2000/NĐ-CP dated October 30st, 2000, 3 new communes were established: Da Ron (of Đơn Dương District), Tan Thanh (of Duc Trong district), B’Lá (of Bao Lam district).

November 17th, 2004 Government issued Decree No. 189/2004/ND-CP established Dam Rong District on the basis of split 05 separate communes north of Lam Ha district and 03 communes of Lac Duong district.

In April, 2010 Bao Loc district is recognized as a city grade III of Lam Dong province.

Nowaday, Lam Dong province has Da Lat city, Bao Loc city and 10 district: Lac Duong, Dam Rong, Don Duong, Duc Trong, Lam Ha, Di Linh, Bao Lam, Da Huoai, Da Tẻh, Cat Tien and 149 administrative units of commune level.

II. Physical Geography Characteristics

1. Topography

A common characteristic of Lam Dong is highland topography similar to other in the Central Highlands provinces.

Highlights of Lam Dong topography is the fairly clear sub-stage from the north to the south. In the north are high mountains, Lang Bian highland with the height from 1,300m to 2,000m as Bi Dup (2.287m), Lang Bian (2.167m). The east and west is low mountain type (height from 500 to 1,000 m). The south is the transition between Di Linh - Bao Loc highland.

Based on the height, it can be divided into four types of topographies:

Mountainous terrain:

Mountainous terrain distributes in the east - northeast and extends in band-shaped to the south, up about 60% of the province. The elevation of this terrain is above 1000 meters. Peaks and rivers is narrow, mountain slopes above 30 degrees.

The valley is in V-shaped with the average cleaved depth of 200 - 300m. Rivers, streams, develop mainly in the form of tree with the density from 2.5 to 4 km/km2. Plant is mainly timber.

Highland terrain

Highland terrain distributes in each arch almost in series and create a band near centre to the northeast - southwest, about 20% of the province.

This type of terrain was created by the denudation surface of basaltic lava creates basins, arches relatively flat, curved and sub-staged marking the eruption phase. Level 800 – 900m is composed of basalt and lake sediment as Bao Loc arch. Level 900 - 1,000 m is also composed of basalt, but was cleaved by stream level 1 and 2 have fire-beam form (typically as the communes in the north and south of Di Linh).

Mountain Peaks In Lam Dong

Mountains

Height (M)

Position

Bi Dup

2.287

South of Lac Duong district

Lang Bian

2.167, 2.064

Xa Lat, Lac Duong district

Hon Giao

2.062

East of Lac Duong district

Chu Yan Du

2.040

North of Lac Duong District

Chu Yan Kao

2.006

Near the river head of Da Dang river

Gia Rich

1.923

Near the river head of Da Nhim river

Lap-be Bac

1.738

North of Da Lat

Lap-be Nam

1.709

East of Da Lat

You Lou Rouet

1.615

West of Da Lat

Yang Kuet

1.431

North of Don Duong

Kanan

1.485

East of Da Nhim lake

Srela

1.486

North of Thanh My

Nui Voi (Quan Du)

1.805,5

On the border of two districts: Duc Trong and Lam Ha

Hon Nga

1.998

North of Lam Ha

Hon Ba

1.529

West of Lam Ha

Serlung

1.233

North of Di Linh

Braian

1.792

South of Di Linh

Tiou Hoan

1.444

North-west of Bao Lam, on river head of La Nga river

B'Nom Quanh

1.131

West of Bao Lam, on river head of La Đạ M'ri stream

S'Pung

1.244

South of Bao Loc

Lu Mu

1.079

East of Da Huoai

Đang Lu Gu

708

East of Da Tẻh

Laet Bite

659

East of Cat Tien

Picture1 : Cleavage From Krong Kno Through Da Lat To Da Huoai

The cleavage of this terrain is average from 0.8 to 1.5km/km2 depending on different levels. Plant here is mainly long-term industrial trees.

The two large highlands are Lang Bian Di Linh - Bao Loc highland.

Lang Bian highland is an ancient valley, from 1,600m - height to 1,400 down to the south, there are high peaks over 2,000m. Its limits in the west, north and east are the arch-shaped mountains with the height nearly 2,000m. Leveled surface is made of shale, sand, powder, clay, ... Eruption sediment was strongly cleaved and created long hills with fairly sloping sides.

There is an ancient east to west valley in Di Linh - Bao Loc highland, the height from 1,000 m to 800m, is covered with mountains with the height from 1.100m to 1.200m.

Bao Loc region, in the height of about 800m with quite large valleys, convex valley sides and slope angle, base and peak are wide and flat.

Adjacent to Di Linh - Bao Loc highland in the south and west is Song Be – Dong Nai peneplains with the height 200 - 300 m and its fields and some mountain with above 300 m height

Picture2 : Da Nhim river valley

Hilly terrain

Hilly terrain makes up about 17% of the province, distributes in band-shaped long to the west - northwest and a part in the south. This terrain with the height of is 800-1.000m and mainly composed of intrusive rocks, late sedimentary Mesozoic and La Nga sediment. This surface was destroyed by remains stream system level 1,2,3 made interrupted, intermittent, narrow and wavy surfaces. The average cleaved depth is 120 - 130m. The slope is 25 - 30 degrees. Rivers and streams is in cathartic, perpendicular or parallel forms with the average density of 1.5 km/km2. Plant mainly is timber and dense vines.

Valley terrain

The valley terrain includes the valley of six major rivers: Da Dang, Da Nhim, Da Queyon, La Nga, Da Huoai and Da The account for Diversity, Nhim, Multi Queyon, La Nga and Da Da Huoai, representing about 3% of the province.

Terrains are in U-shaped and V-shaped valleys, hollow and wide trough in sunken block form. V-shaped valley was developed in early Kainozoic stone. U-shaped valleys and trough were developed on basalt highland filled with young sediments. The widen sunken block was filled with Quaternary and Neogen sediments. The terrain surface creates steps and alluvial.

2. Geology

Geological structure of Lam Dong province includes: sedimentary, eruptive and intrusion stones with the age from Jura to middle Quaternary. The sediments, eruptions are divided into 14 stratigraphic levels with various compositions and age stones. The intrusion stones in Lam Dong province includes 4 complexes: Dinh Quan, Ca Pass, Ca Na, Cu Mong.

Stratigraphy

Mesozoic period

The sedimentary eruption of Mesozoic period is separated into four layers: La Nga, Bao Loc Pass, Da Krium, Don Duong.

Jura layer, intermediate age, La Nga layer

On the area of Lam Dong Province, the sediment of La Nga layer is exposed quite widely in Da The, Cat Tien, Loc Thanh, Da Queyon (Tra Nang), Phi Lieng river, Krong no upstream. The total thickness of this layer is 1.300m.

On the Lam Dong area, La Nga layer is located unconformity under Bao Loc pass layer, Da Krium layer and Don Duong layer.

Jura layer, superior age, Bao Loc Pass layer

The stone of Bao Loc pass layer is distributed in the southeast of Bao Loc pass, the south and southeast of Di Linh, northeast of Gia Bac, southwest of Ta Nung mountain.

Petrography compositions of the layer are: andesit, andesit porphyrit, andesitodacit, dacit, ryodacit, ... Overall thickness of the layer is 400 - 500m.

Cretaceous layer, superior age, Da Krium layer

The stones of this layer are exposed along Da Krium stream, Nhim river from its mouth to Lien Khuong, the northeast of Lam Ha in sloping type, 5-10o slope angle.

Layer thickness is of about 120m. The age of the layer is temporary ranked into late Cretaceous on the basis: the stones of Da Krium layer is located angular unconformity with the stones of La Nga layer and is covered by the acid eruption stone of Don Duong layer.

In the sediment of layer contains late Jurassic age animal, plant fossils - Cretaceous or Cretaceous - Paleogen.

Cretaceous layer, upper age, Don Duong layer

The stones of Don Duong layer are exposed over a 20km2 area and lengthened over 70km from the Prenn Lam Ha, Xuan Tho to Da Nhim upstream. In addition, the stone of this layer can be met in Tra Nang, Queyon mountain, Ta Dung with an area of 10 - 30km2.

Picture3 : Lam Dong Outline Map

The layer is composed of rock dacit, ryodacit, felcit, ryolit, andecitodacit pyrocrastics, and andesit thin layer in some places. Overall thickness of the layer is 1200-1.300m.

Kainozoi period

The friable sedimentary rock and basalt eruptions develops widely in the area of Lam Dong province. They are divided into 10 stratigraphic units are late Miocene to Holocene age. Quaternary-age sediments are often friable and along the rivers, streams. The basaltic eruption stones often form large overlays.

Neogen layer, Upper Miocene age - Lower Pliocene age, Di Linh layer

The sedimentary clay, bentonite, diatomite, lignite are exposed at Di Linh, Phu Hiep.

Overall thickness of the layer is 100 - 214m.

The basalt eruption sedimentary stones of this layer is covered by basaltic eruption of Tuc Trung layer.

The age of the layer through the analysis of pollen spores, plant fossils value 9.38 ± 0.4 to 13.1 ± 0.6 million years.

Neogen layer, Pliocene age, La Nga layer

La Nga layer distributes along Da Dang river and a large field of Bao Loc and Di Linh with the absolute age of 5-8 million years, some areas to 13.1 ± 0.6 million years.

Basalt thickness is unstable, changing from 30-40m to 300m.

The basalt of La Nga layer lye unconformity on prior Kainozoine stones, its surface is covered by Pliocene basalt - Quaternary of Tuc Trung layer.

Neogen layer, upper Pliocene - Lower Pleistocene, basaltic eruption, Tuc Trung layer

Plagiobazan alkaline olivine in Da, Cat Tien Loc Thang, north Di Linh, Tan Van, Da Queyon river basin are classified into Tuc Trung layer. These basalts are weathered strongly and often creates bauxite.

At Tan Rai area, many original tectonics pieces were found on the weathered cover of this basalt. At Tan Phat (Bao Loc) airport, tectonics sample can be found with the absolute value of 0.57 million years old.

Basalt thickness varies from 10 to 60m. Bazan of Tuc Trung layer lye unconformity with the sedimentary, basaltic eruptions of La Nga layer, Di Linh layer.

Quaternary layer, middle Pleistocene age, basaltic eruptions, Xuan Loc layer

Xuan Loc basalt eruption is in in the area Lien Khuong, Ka Do, Lam Ha, Xuan Tho and Xuan Truong.

This basalt covers unconformity over the eruption sediment of Di Linh layer.

Basalt thickness varies from 40 to 50 m to 150m.

Quaternary layer, middle-upper Pleistocene age

River derived sediment with middle-upper Pleistocene age is distributed along Da Nhim, Da Queyon and create level III self. Its composition consists of conglomerate, grit, sand, flour and a little clay. Level III self distributes in a relatively height: from 15 to 20 m (in Da Chais) and 20 to 30 m (in Tra Nang).

Quaternary layer, Upper Pleistocene

River derived sediment with middle-upper Pleistocene age is distributed along Da Nhim, Da Queyon and create level III self. This self is in a relatively height: 10 - 15 m, 100 - 400 width, often interrupted. Its composition consists of: pebbles, gravel, sand and little powder, clay with a thickness of 80-10 m, often contain gold and tin.

Quaternary layer, Holocene age

The Holocene sediments are widely distributed in the Da The valley, Cat Tien, Da Huoai, La Nga, Da Nhim, Da Queyon rivers and small streams.

Quaternary layer, river sediments, slopes, flood at undivided Holocene age

Distributed mainly in the small streams of Da Queyon river and consisted of boulders, gravel, sand and clay.

Magma intrusion

The intrusive stones within Lam Dong province are quite developed and classified into four complexes: Dinh Quan, Ca Pass, Ca Na, Cu Mong.

Late Jurassic intrusion, complex Dinh Quan

Dinh Quan complex intrusive surfaces develop quite extensively, forming large blocks: Song Pha, Loc Nam, Son Dien, Bao Thuan, Madagui, Da Me, Da Chais.

The main trade elements are: Be, Mn, Ti, Cu, Y, Yb.

Dinh Quan complex intrusive stones carve La Nga layer sediment stones, erupted andesit of Bao Loc pass layer. They are covered by the stone of Don Duong layer. The age of the complex is identified as late Jurassic age with absolute value is 144 million years.

Cretaceous intrusion, Ca pass complex

Within Lam Dong province, the intrusive formation of Ca pass only exposes in Tra Nang, Da Mi, Nam Madagui. They create small blocks with size from a few km2 to 10 - 15km2.

The main trace elements are: V, Ga, Be, Yb, Zr, Cu, Pb, Zn, Sn with low contents, notably Mo.

The intrusion of Ca pass complex intrusive La Nga layer sediments, Dinh Quan complex granite. The age stone of complexes are classified into non-dividing Cretaceous age basing on absolute age follows: 126 ± 3; 119 ± 2; 98 ± 3; 78 ± 1 million years.

Late Cretaceous intrusion, Ca Na complex

Within the province of Lam Dong, the intrusive formation of Ca Na complex are mainly in: Dam Bri, Da Prou, Phu Son – Phi To - Cam Ly, Yuk Reap, ... They create intrusion volume size from 20km2 to 2.000km2.

The trace elements commonly associated are: Yb, Cu, Zr with low contents.

Age of the Ca Na complex stone is late Cretaceous: 110 ± 1 and 100 ± 2, 95 ± 1.8 million years.

Paleocene intrusion, Cu Mong complex

The stones of Cu Mong complex develops in Trai Mat in the form of barleys from a few dm to meters, tens of meters long.

The stones in gabbroid alkaline group - Alkaline monzonit K – Na; Na properties is superior to K, aluminum contain from low to high.

Associated trace elements commonly is Cu.

In the barley of complex has sulfur mineralization.

Petrography composition of complex stone includes: gabrodiabaz, gabrodiorit, gray green porphyry.

The stones of Cu Mong complex go through Ca Na, Dinh Quan complex intrusive stones. The age of the complexes is in the same age with radioactive isotope 43 ± 1 million years of gabrodiabaz

3. Tectonic

Tectonic position

Lam Dong province locates in the southeast of Da Lat zone. This zone is a Precambrian continental crust block was subsided in early-middle Jura. Most area of the zone was tectonically magmatic activated in late Mesozoic and Kainozoi.

Deep structure

According to geophysical gravity document of Lam Dong province, the depth of Moho surface is 32.5-37km, of Conrat surface is 15-18km, of crystalline basement surface is 2-5km. All these surfaces are oriented in the depth gradually from southeast to northwest. They are the southeast part of large Dalat hollow with hollow center in Ankroet-Tay Son.

Petrofabric tectonic

Middle Jura includes near-shore shallow sea terrigene sediment stone, with 1,300m thickness, is deposited in the interior basin of Da Lat. Over the following magma –tectonic activities, mainly in the late Cretaceous, these sediments were folded and crumpled strongly, some spaces were temperature metamorphosed creating relatively large contacting external zone in the north of Da Lat. These folds are in linear forms, extending in north east – west direction with axial surface inclined to the northwest, the angle slope of surface is 50-600.

Upper Jurassic - Cretaceous was constituted by the intrusive eruption stones of Bao Loc alkaline limestone layer, Dinh Quan complex, Ca Pass complex. The eruption formation is almost in horizontal, directly above Jurassic sediments. The intrusive stones create bed and base. In general, these intrusive shapes prolong in northeast – southwest direction.

Upper Cretaceous includes red terrigene sediments of Da Krium layer, neutral eruption, acid of Don Duong layer and bright alaskit granite, mica 2 granite containing tin of Ca Na complex. The intrusive blocks are cylindrical, base with the size from 20km2 to 2.000km2.

Paleogen - Miocene - Pliocene were created by gabrodiabaz stone, basalt tholeit eruptions and lakes sediments.

Pliocene - Quaternary includes the alkaline olivine basalt covers in Duc Trong Tan Van, Cat Tien, Loc Thang and the loose sediment formations of Quaternary age that distributed along the rivers, streams.

The main geological block

On the area of Lam Dong province, 3 following geological blocks are recorded:

Da Lat block: with the extensive development of the granite of three complexes: Dinh Quan, Ca Pass, Ca Na. Da Lat block centre develops acid eruptive hollow and red sediments in Cretaceous age.

Bao Loc - Di Linh block: The specification of this block is the development of extensive basalt cover in Neogen – Quaternary age. The southern of block has andesit eruption coating in late Jurassic age.

Madagui block: formed by sediments of La Nga layer, covered unconformity by Quaternary loose sediments and Neogen – Quaternary basalt.

Fracture

The Fracture in this area is quite developed and classified into three categories: northeast - southwest, northwest - southeast and sub-longitude.

Northeast - southwest fracture group includes the main fractures: Da Teh-Da Koi; Bao Loc – Nam Tuon; Loc Thanh - S'Lung; Dinh Van - Da Lat; Da Dang - Xuan Tho, Da Nhim - Lac Nghiep; Kanan - Nhim; Nam Xa Loan - Cha Bou. There are three main activities of this fracture group: negative phase to Cretaceous with its northwest up throw southeast, right horizontal positive phase to Neogen, left horizontal positive phase to Pliocene - Quaternary.

Northwest - southeast fracture group includes fractures: Loc Lam-Di Linh; Tung Nghia - East Tra Nang and Da M'rong - Cam Ly stream. The slip surfaces of fractures are mostly in vertical, moved to horizontal in Pliocene - Quaternary.

Semi-longitudinal fracture group includes fractures: Madagui - Da Kroton; Kondrout - Huong Lam; Lam Lo - Da Krium. The slip surfaces of fractures are mostly in vertical, cracked in Pliocene - Quaternary.

History development

Area geophysical and geological documents state that roughly this area as well as Da Lat zone are Precambrian continental crust. In early Mesozoic Paleozoi, it was predicted here could have gone through periods: sunk to create an base coating, activated - create.

Early-middle Jurassic: this region as well as Da Lat zone was subsidented forming internal basin and filled with includes near-shore shallow sea terrigene sediment stone. In middle Jura, the sea was closed and after Bajoci sediments finished.

Late Jurassic - Cretaceous: This area as well as Da Lat zone were raised and folded into blocks, together with strong magmatic activity, eruption formation, alkali lime intrusion alkali that relating to the subduction process of ancient Pacific under the southeast continent of Asia part. Don Duong hollow was appeared in last Cretaceous, initially filled with red continental sediments. Then the volcanic activity and high alumina acid intrusion due to partially molten continental crust, marking the formation of late Mesozoic new continental crust at the edge of East Asia.

Paleogen - Miocene: This area is raised repeatedly and eroded strongly, creating leveled surface. This is one part of large Indochina leveled surface. Neogen period associated with the separation of South Sea, in the studied territory appears the basins filled with sediments and basalts extending to the north east - west, together with right horizontal positive fracture.

Pliocene - Quaternary: This zone is kept rasing strongly in arch, block - forms foundation and in East-West tension. Appear alkali olivine basalt, along the rivers, streams appear loss terrigene sediments. The processes of weathering, erosion act as the exogenous activities

4. Mineral

Minerals in the area of Lam Dong province is appeared in the mineralization era of late Mesozoic - early Kainozoi and Kainozoi

The late Mesozoi – early Kainozoi mineralization era is a period of activated magma – it is most powerful created and formed a subsidiary of Dalat - Bao Loc mineralization. This era is characterized by mineralized Au, Ag, Sn, W, Pb, As, and a number of mineral of construction materials.

The Kainozoi mineralization era is period of active magma – it ttectonics along the skin penetration depth, formed a series of hollow areas among mountains and extensive basalt cover. This era included many types of endogenous and exogenous ore, richness and diversity such as bentonite, diatomite, jewel, and gemstone, clay, gold, tin, wolframite (mineral), sand, pebbles, gravel and hot water

Geological Division No 6 has synthesized 165 mineral deposits, including 23 large mines, 3 medium mine, 48 small mine and 91 ore deposits. The mines and ore deposits are divided into seven groups: coal, metals, non metals, construction materials, jewelry, ggemstone, abnormal radiation, mineral water and hot water.

Coal

In the area of Lam Dong, there are 2 kinds of coal: lignite and peat.

Lignite

Lignite was formed in the narrow valley with lake sediments belonging to Di Linh floors with a total volume of about 8,577,730 tons .

In the mines and ore deposits of Dai Lao, Da SRO, Sum Brac, Dinh Trang Thuong, Lam Son, the lignite deposit of Dai Lao has the best thickness and quality wiht 4 coal-streams.

Peat

Peat was formed in the modern swamps amd rivers, by the orignal of native marsh sediments, age of Neogen with a total volume of about 1.5 million m3.

Picture4 : Geological – Mineral Map Of Lam Dong Province

In Lam Dong, these mines have discovered: Lap-be Bac, Da Thien, Da Klou Kia, Kim Le, Man Ling and mineral deposits: Phi Lieng, Chien Thang lake, An Binh, Đai Lao.

In those peat deposits, Da Klou Kia and Kim Le are 2 rather quality mines with bigger deposit than other, convenient transportation, about 2km far from Di Linh town, easily exploiting conditions for the production of fertilizer.

Metal

In the area of Lam Dong, the metal ores are: iron, wolfram, lead, antimony, bauxite, tin, gold.

Iron

Iron ore in Lam Dong is poor, it only included 2 ore deposits in Kom Tat and Lien Dam.

Kon Tat ore deposit is in the system of quartz – hematite with hydrothermal origin. Iron ore is in cross-cutting quartz canal of of Ca Na complex granite which was mined from 1909.

Lien Dam ore deposit is derived from literate weathering of olivine basalt belongs to the La Nga floor. Ore is distributed on the surface in the form of rigid ball, slag, red brick color, laid together in red literate soil. Volume of about 2.784 million tons.

Wolfram

Wolfram in Lam Dong Province is of wolframit and has just been discovered mineral wolframite in Loc Bac, row mineral wolframite in Loc Lam. These ore deposits was mined from long time .

Lead - zinc

Gia Bac lead – zinc is of the multi-metal sulfur systems (lead-zinc-copper-silver-arsenic) with hydrothermal origin, locates in Gia Bac ore canal.

Eastern ore zone locates in the east of the regional fracturing area, distributed along Phan Thiet - Di Linh and estimated 6,750 tons of lead (Pb).

West ore zone locates in the west of the eastern ore zone via fracturing, nearly matchs together with Phan Thiet - Di Linh, it is forecasted with reserves of: Pb = 101,250 tons, 50,625 tons.

Antimoan

Lam Đong has antimoan deposit in Tien Hoang (Cat Tien). Ore bodies crossed in to the clay layer, powder, fine-grained sands of La Nga floor.

Ore composition is mainly asenopyrit disseminated with antimonit, pyrite, sometimes, there appered some sedimentary rocks. The metal elements symbioticed with antimony are: Ag, Pb, As, Sn, Cu, Zn. Estimated reserves is of 25,000 tons.

Aluminum

Aluminums minerals in Lam Dong province is bauxite literate ore in weathering crust of Tuc Trung floor with the total reserves of 1,114 million tons

Ggeological researchers have found two bauxite mines with the industrial value in Tan Rai, Bao Loc and 6 ore deposits in Riong Tho, Dang Kla, Lan Tranh, in the west mountain pass of Bao Loc, Son Dien, Gia Bac.

Tin

Tin mineral in Lam Dong province is casiterit ore located in Dalat - Bao Locsub-tropical mineralization. Here, tin is included the original tin and placer tin.

Original tin has the orgin of hydrothermal and pegmatit with a total volume of about 130,000 tons of Sn02

It has been discovered three large mines in Nui Cao, Thai Phien, Da Thien, 1 medium mine in Da R'Hoa; four small mines in Da Chais, in the north of Xuan Thanh, in the east of Da Nhim River, Phu Son and 3 ore deposit in Nui Khon, Da Thien, in the east of Thai Phien.

Placer tin has the total reserves of 1.793 tons SnO2.

Geological Division No 6 has discovered the following mines: Da Chais, R’Teng, Da Rdiou, Da Rdeo; people has discoverd and mined mines: Nui Cao, Da R’Hoa, Thai Phien, Hoc vien Luc quan (army academy), Song Con, M’Palou, Ta Bo mountan, Hoa Bac, Son Đien, Bao Tuan, Da Tanki, Loc Tan, Loc Bac, Loc Lam and 2 ore deposits: Da Thien, Bang Tien.

Gold

Gold is one of the important minerals and widely distributed in the province including original gold and placer gold.

Orginal gold has the predicted reserves of about 10,148 kg Au and 15,637 kgAg.

Gold with the hydrothermal origin was formed from three formations: gold-quartz, quartz-sulfide-gold, sulfur-gold-silver.

Quartz - gold formation contains sulfur (less than 5%), was discovered in Dai Ninh goldmine, gold ore deposit of Man Ling, Sao Nam. This formation is is not common and occupies a small proportion.

Quartz-sulfide-gold formation widely developed and occupieds a large proportion. It was discovered Tra Bang Goldmine and ore deposits: Xuan Thanh 1 Xuan Thanh 2, Trai Ham, Da Chais, southern Pta Bou, Gia Oa 1, southern Teurlang Dong hamlet, Yrlang Teurlang, Tay Son, Phi Lieng, north-west Phi Lieng.

Sulfur-gold-silver formation developed relatively in eruptive rocks of Don Duong floor, but low gold content, only Tuy Son gold deposit can meet the industrial content. .

Placer gold: it is discovered 7 small mines, in which, Tra Nang orginal gold mine has the reserves of about 652kg. Mines: Tay Son, Dam Voi, Phi Lieng, Da Ding King, Da N’Bo, Da P’loa are mines with small dimension, people has been mining.

Nonmetallic

Kaolin

Kaolin mine in Lam Dong derived from weathering and sedimentation. It has been discovered two large mines in Trai Mat, Prenn and 4 ore deposits in B'Nam, Teurlang Tho hamlet, Ngoc Son, Lac Nghiep with the reserves of 127,866,021 tonnes .

Felspat

Felspat in Lam Dong has the origin of pegmatite. The cross-cutting pegmatit cannal in tropical circuit contacting between granite - biotic complex of Ca Na and La Nga floor.

Bentonit

Tam Bo mine and 3 ore deposits has been discovered are Da Kria, Da Le and Di Linh.

Bentonit in Lam Dong were formed from lake sedimentation of Di Linh floor with the reserves of 11.241.430 tones.

Diatomit

Diatomit is in lake sedimentation of Di Linh floor, forming thick sections or lens accompanying with lignite of Dai Lao; Loc Son ore deposit of lignite and diatomit clay. Total reserves are 63.920.000m3.

Construction material

Construction material group are divided into two subgroups: natural construction material and construction raw material.

Natural construction material

On the area of Lam Dong province, the minerals of sub-groups are popular, including: sand, gravel; granite construction stone, riolit, andesit, basalt; granite devitrified stone, dacit, gabrodiabaz.

Construction raw material

Construction raw material included clay and marl.

Clay is a mineral form extensively developing in Lam Dong province. Now, 15 deposits has been discovered, including three large mines, three small mines and 9 ore deposits with the total reserves of 146.480.000m3.

Whole clay deposits has two sources: sediment and weathering..

Marl in Lam Dong were very restrict distributed, it only created the thickness of 1m, located in eruptive sediment of Bao Loc mountain pass floor. Two deposits in Don Duong has been discovered in this area.

Jewelry and Gemstone

Saphyr

Local formations with saphyr are basalt, eruptive andesit stone and tuf of Bao Loc moutain pass floor and intrusive biotit granitic rock of Dinh Quan complex. But the origin of saphyr is basalt with alkali (alkali basalt). The place consisting of saphyr is aluvi sediments in alluvial ground and level I ground. It also was formed from deluvi sedimentary.

In Lam Dong, it has discovered 2 mines in Tien Co, Sa Vo and 4 ore deposits in Lam Ha, Krong Klet river, Xuan Truong, Son Dien.

Tien Co mine has the reserves of about 678.18 kg. The average concentration of saphyr in the product layer is 3.55-12g / m3. Saphyr has the light green to dark green color, high reflecting levels. Saphyr commercial product rate reached to 11.7%, the grain accounted for 1-2% over 6 carats. General distribution area of aluvi and deluvi sediments with saphyr are 180-4.000m of width, 2km of length

Topaz and quartz crystal

Topaz quartz deposits was discovered in 1991 from stream valley in the region of Loc Tan commune. These valleys are narrow with 10 -15m width. Milky Quartz with the color of milky, white, smoky and the size is from some centimeters to 0.4 dm. Quartz also have prismatic shape.

Quartz crystal deposits in point in Sum Brak valley has the hydrothermal origin, placed in the quartz canals developing in the holes of granite in Dinh Quan complex.

Opal

Opal is a kind of gemstone with hydrothermal origin occurred in quartz canal, developed in the Tuc Trung floor. They was in form of circuit, hard, bump due to weathering of basalt destroyed by stone and taken to hillside.

Opal was in the valley of Da Nhim river, Da Si Chu, Di Linh, Bu Ni Nho, Phu Hiep with the size of rolling stone from some dm to 5–6dm, color of milky, grey, light yellow, red brown.

Tectit

Tectit with the cosmic origin has been found in many places of Lam Dong. They located on the erosion surface that occurred in the early Pleistocene. In many places, tectit was taken down and precipitated on steps, alluvial grounds of valleys with the age from middle Pleistocene to Holocene. Tectit can be found in shape of teardrop, peach seed, sphere, rod and color of dark gray, master black, it was used for jewelry and fine art

It has discovered 7 ore deposits of Da Lat, Plang Dra, Cau Dat, Duc Trong, Ninh Gia, Tan Phat, Dai Lao.

Radioactive group

In the area of Lam Dong province, there have four radioactive deposits that can be classified into ore deposits, in which, three ore deposit are of Don Duong eruptive rock floor and one of Ca Na granite complex.

Dinh Dan radioactive deposits: Radioactive rocks are in felsit cannal, 25 - 30m width, lengthened 150m across the Asian longitude direction of Don Duong eruptive rock floor. Radiative intensity value: 100-300 μR / h, the highest is 900 to 1700 μR / h. Concentration: U = 86.4 g/tonnes; Th = 13.7 g/tonnes; Ce = 58.2 g/tonnes; La = 35.4 g / tonnes; TR = 128.5 g / tonnes

Quang Du radioactive deposits: Radioactive units are in tuf, felsit porfir, sulfur (rolling stone) with radioactive reaches 150 - 200 µR/h, highest 720 µR/h. Concentration U = 296g/tons; Th=25g/tons; Ce=159,9 g/tones; La = 119,3g/tonnes; TR = 474 g/tones.

Da Prenn radioactive deposits: Felsit porfir stone canal has the structure of stripe, 1m – 2m width, in the northeast – southwest of Don Duong eruptive rock floor

Radioactive intensity around felsit porfir cannal is 26 – 28 µR/h.

Concentration U = 52.9 g/tons; Th = 18 g/tons; Ce = 55.7 g/tons; La = 38.6 g/tons; TR = 117.3 g/tons.

Gia Oa radioactive deposits: Radioactive units are distributed in light-colored granit porfir influenced by quartz canal of 10o - 190o direction. There are also green quartz canal cross-cutting granite and above quartz. Radioactive rocks are usualy from 80 to 100 μR / h

Concentration U = 2.7 g/tons; Th = 126 g/tons; TR = 1,244 g/tons

5. Soil

Lam Dong has land area of 98% natural area, equivalent to about 965,969 ha, including 8 soil groups and 45 land units.

1. Fluvisols was formed from the sedimentation of rivers, streams. Change of soil characteristics is depended on the weathering products of formed soil samples in the upper streams of each river basin, time and conditions of sedimentation. This land group includes 3 land units: sour fluvisols, humus- rich fluvisols, Glay fluvisols with the total area of 28,866 ha

2. Gleysols was formed in the low-hollow topography, shallow water levels creating conditions for occurring of deoxidize progress that make land green, water into land. This soil group consists of 5 lan units: Glaysols with human effective sweating water, Glaysols with hollow grit floor, Acid- rich Glaysols, humus-rich Glaysol, Glaysol on the humus-rich surface with the total area of 44,685 ha

3. Cambisols was formed during the leaching conditions, ferrallitization, laicization. This soil group consists of 5 land units: new nantural sweating water soil, new acid soid, new humus-rich soil, new soil with acid yellow-red flayer, new natural sweating water soil has a total area of 16,275 ha

4. Luvisols was formed by the leaching process for clay accumulation. This group consists of 3 land units: Acid black soil, humus-rich black soil, black soil with yellow-red flayer layer, total area are 2,981 ha.

5. Ferralsols was formed by the weathering process of clay creating low active minerals, no weathering property as kaolinite, accumulating Fe / Al oxide and their sustainability. This group consists of 10 land units: humus-rich acidic red soil, basic-poor red brown soil, acidic yellow red brow soil, basic-poor red soil, very basic-poor and humus-rich red soil, very basic-poor hollow gravel red soil, very basic-poor deep gravel red soil, hollow gravel red soil, total area is of 212,309 ha

Picture5 : Lam Dong Land Map

6. Acrisols was distributed in almost districts, from high mountains and low-hollow hilly terrain and valleys on the original rocks. This soil consists of 17 land units: gray-yellow-red soil, gray soil with rotten layer, typical gray soil, humus-rich gray soil, humus-rich soil, aluminum gray soil, very sour gray soil, very sour yellow-red gray soil, very sour and basic- poor grey soil, very sour grey soil with hollow gravel, very sour grey soil with deep gravel, hollow gravel grey soil, grey soil of humus-rich and very sour layer, hollow gravel and humus-poor gray soil on surface, thin surface grey soil, total area: 659,648 ha

7. Alisols was distributed on the mountainous terrain with the heigh of above 2,000 m, formed in areas with cold climates, high humidity round year, this soil group consists of only one land unit: Alisols with the total area of 864 ha.

8. Leptosols is distributed mainly in hilly land, formed by the progress of leaching, erosion the surface by water, wind, ... The characteristic of this soil is that the fine soil thickness <30 cm, This soil consists of one unit of strong erosion soil, base and acid rock with the area of 68 ha

6. Climate

According to climate classification, Lam Dong province’s climate belongs to the area No 4 of Central Highlands with monsoon tropical climate. On the whole territory, due to complex terrain, it has differences of height and cover rate of vegetation. However, Lam Dong has temperate climate, it is warm around year and rarely change yearly.

Air temperature

Results of monitoring of temperature varies of Lam Dong (Table 1) recorded by the meteorological station (Doi Cu Station periods 1977-1991, Bao Loc station period 1981-1990, Lien Khuong stations in 1995) tell us that Lam Dong temperature changes significantly across the regions, more higher area more temperature decreases (Table 2). Average of yearly temperature changes from 16o to 23oC. The average temperature difference between months of the year in each area is not much, although day/night temperature amplitude is high, especially in high areas such as Da Lat

Table 1: Air Temperature In Lam Dong

Month

Temperature ( oC )

Medium

Extremely high medium

Extremely low medium

Extremely hight

Extremely low

A

B

C

A

B

C

A

B

C

A

C

A

C

1

15,8

20,0

19,8

22,5

30,3

27,3

11,4

11,6

15,0

26,5

30,6

5,1

9,1

2

16,6

21,0

19,3

24,1

31,7

27,9

11,5

11,4

14,7

31,2

30,4

5,3

11,9

3

17,9

22,2

21,1

25,4

32,2

29,0

12,6

14,0

17,5

29,5

32,1

7,2

12,4

4

19,0

23,1

23,0

25,4

32,2

30,6

14,5

16,1

17,7

29,2

31,3

9,0

16,4

5

19,4

23,3

22,7

24,6

34,5

28,9

16,0

17,8

18,5

27,6

31,4

12,0

15,8

6

19,0

22,6

22,3

23,2

31,0

28,9

16,3

18,8

18,9

27,2

30,8

12,3

18,3

7

18,7

22,3

21,9

23,0

29,4

27,7

16,0

18,1

18,6

26,3

30,3

13,0

17,7

8

18,6

22,1

21,9

22,5

28,8

27,7

16,3

18,5

18,7

26,0

29,8

12,9

18,3

9

18,4

22,0

21,6

22,8

29,9

26,6

15,8

17,5

19,0

26,4

29,0

12,0

18,6

10

18,0

22,0

21,3

22,5

30,0

27,0

15,1

17,2

17,7

25,9

30,0

10,3

18,0

11

17,2

21,3

20,6

21,8

30,7

26,0

14,3

14,4

16,6

25,6

20,7

8,7

14,9

12

15,9

20,0

19,9

21,5

29,6

25,9

12,4

11,9

15,6

25,8

20,3

6,7

10,4

Source A: Doi Cu meteorological station (1977-1991)

B: Bao Loc station (1981-1990)

C: Lien Khuong station (1995)

Table 2: Characteristic Of Teperature Distribution As Per Altitude

CHARACTERISTIC

Elevation ( m)

< 500

500-1.000

1.000-1.500

> 1.500

Annual average temperature(0C)

>22

20-22

18-20

<18

Monthly average temperature (0C)

>20

18-20

16-18

<16

Compared to other deltas with the same latitude, Lam Dong temperature is lower but the yearly temperature variation is very similar

Humidity

Hhumidity is one of the micro-climate factors affecting to social life as well as to the adaptation and development of the ecosystem, including animals and plants.

Due to the geography and topography, the humidity in the area of Lam Dong province is also different (Table 3)

Table 3: Humidity Of Lam Dong

Month

Humidity ( %)

Da Lat

(1977-1991)

Bao Loc

(1981-1990)

Lien Khuong

(1995)

1

80

79

73

2

77

77

69

3

78

79

70

4

84

83

73

5

87

87

80

6

90

90

85

7

90

91

87

8

91

92

88

9

91

91

90

10

89

90

89

11

85

87

86

12

82

83

78

Relative humidity in the months of rainy season is quite high (84-91%). There have the have the largest relative humidity (90%) in June, July, August and September. The dry months: 69-83% in Da Lat, in Lien Khuong 73-80%, 83-92% in Bao Loc

Rainfall regime

Lam Dong terrain is separated complexly and sloped from northwest to southeast, from average altitude above 1,500 meters in Da Lat down to 300 meters in Da Huoai. So that, the rain regime of Lam Dong has the characteristics depending on terrain separation and altitude (Table 4).

Table 4: Rainfall Regime Of Lam Dong

Month

Da Lat (1977-1991)

Bao Loc (1964-2000)

Lien Khuong (1995)

Total rainfall (mm)

Day numbers

Total rainfall (mm)

Day numbers

Total rainfall (mm)

Day numbers

1

6

1

60

5

6,7

2

2

14

2

52

5

92,1

4

3

61

6

105

8

92,9

5

4

166

13

211

14

52,3

6

5

176

19

242

20

207,2

17

6

200

24

302

22

186,0

18

7

239

25

390

25

234,0

25

8

242

25

455

26

239,8

27

9

309

26

405

25

272,9

28

10

237

21

327

23

243,7

16

11

90

12

173

14

56,0

9

12

16

4

92

8

9,2

5

Many year

1.756

178

2.762

195

1.693

162

Rainfall

Annual rainfall is distributed irregularly on space and time, ranging from 1600 - 2.700mm. The rib extracting southwest wind (Bao Loc) has a large annual rainfall up to 3.771mm

Maximum total of annual rainfall, season rainfall, monthly rainfall change according to richness or absence the southwest wind.

Da Huoai and Bao Loc is situated on the southwest wind side, so the maximum rainfall month is August, while Lien Khuong and Don Duong are absent from win so maximum rainfall month is September (table 5)

To the east, northeast, rainfall is decreased , only 1.756mm.

Especially, in the valleys among high mountains, rainfall is less than 1.400mm .

During dry season (from November to March), due to the influence of North-East monsoon, Lam Dong rainfall is very little, it is only 10-15% of rainfall of all year. Some year, There are 2-3 months without rain or negligible rain

The rainy season coincides with the southwest monsoon. Rainfall during this season accounts for 85-90% of annual rainfall; Some years, heavy rain, continuous rain has caused flood in some areas along Da Nhim river and 3 southern districts: Da Huoai, Da Teh , Cat Tien, making great damage to crops

Table 5: Rain Characteristics

Characteristic

Southwest wind side

Absent wind side

Da Huoai

Bao Loc

Lien Khuong

Don Duong

Total annual rainfall (mm)

3.280

2.762

1.693

1.716

Rainfall of rainy season (mm)

2.702

2.332

1.436

1.387

Maximum rainfall month

7

8

9

9

Peak rainfall

1

1

2

2

Rainfall day and Intensity

Average number of rainfall days are 162 - 195 days. In the dry season, there have only 15-20 rainfall days in areas of low rainfall and 40 rainfal days in which much rainfall.

Daily rrainfall intensity is distributed as following

Daily rainfall from 0,1 to 15mm is accounted the frequent rate of 65-80%.

Daily rainfall from 15,1 to 50mm usually occurs during the rainy season with a of 20-30%

Heavy rainfall with the intensity of over 100mm/day is rarely happened.

According to measurements, Bao Loc has the largest amount of rainfall reached to 455mm, while the others have not exceeded 150mm/day

Rainfall periods

The starting and ending time of rainy season

Rrainy season of most areas in province begins in the mid-April, particularly for the eastern, north-east, it just begin in early May

Rainy season usually ends in late October and early November. Da Huoai Area, Bao Loc is situated in the southwest monsoon side so rainy season lengthen and lately end (mid November).

In fact, in April, May, the southwest monsoon just starts, it is almost showers and thunderstorms in the afternoon. When the southwest monsoon season is stable, the rainy season of Lam Dong is also table.

Rainfall and rainy days

The less rainy month is January or February. Monthly average rainfall is about 6 - 14mm in low rainy place, 41 mm - 52mm of high rainy places. The remaining period of dry season has monthly average rainfall from 16mm to 40mm

During rainy season, all month have the rainfall over 150mm, more to mid-season, rainfall is more greater. In the south, south-west, rainfall has only one peak in July or August; in other places there is only one major peak in September. Monthly average rainfall of these months reached 250 - 300mm of low rain places, 300-400mm of high rainfall places; secondary peak occur in early rainy season (Monthly rainfall of May is around 200mm).

Rainfall of November in all the places is smaller than in October from 85mm to 147mm

Number of rainy days of July, August, September are fluctuated from 25 days to 28 days/month; The rainy day number of January and February are not over 4 dáy; các The remain month has the rainy days about 5 days to 24 days.

Wind and direction

Average wind speed in Lam Dong is 2.1 m/s and maximum wind speed recorded in Da Lat is 23m/s (Table 6)

Dalat is far from sea so it is less directly affected by the storm, but the yearly average wind speed is relatively large compared with deltas. Winter wind speed is usually greater than the summer. Seasonal wind direction is usually stable

According to monthly average wind speed and windless frequency, we can divide wind in Da Lat into 3 periods:

Windless period: March and April, monthly average wind speed is 1,1-1,3m/s, windless frequency is over 50%.

Breeze period: January, February, May, September and October, monthly average wind speed is 1,5-2,1m/s, windless frequency is 35-45%.

Heavy wind period: June, July, August, November and December, monthly average wind speed is 2,5m/s, windless frequency is 15-30%.

Heavy win period of Da Lat is divided in to 2 periods:

In the first phase, due to the strong activity of western wind occurred on June, July, August, so wind speed observed of this stage is 23 m/s.

To November and December, the northeast monsoon strongly overflows in the north country and heavy wind appears in Da Lat for the second time of year Northeast monsoon normally affects to the southern provinces, Da Lat is affected by this wind quite clearly due to its height of above 1,500m. On November, December, the average wind speed is up to 2.9m to 3.2 m/s. The most speed is 19m/s. Heavy wind occurred continuously in phase, each phase lengthen in several days, sometimes up to 5, 6 days

At Lien Khuong, windless frequenecy is 28,9% and 1,3% in the north, 21,4% in the east (table 7).

Table 6: Average And Maximum Wind Speed In Lam Dong

Month

WIND SPEED (m/s)

AVERAGE

MAXIMUM

A

B

A

C

1

2,1

1.2

19

12

2

1,5

1.1

15

12

3

1,3

1.3

16

12

4

1,1

1.0

16

12

5

1,5

1.1

18

9

6

2,8

1.9

20

19

7

2,6

1.7

16

9

8

3,4

2.0

23

10

9

1,7

1.2

18

9

10

1,7

0.9

18

7

11

2,9

1.0

18

10

12

3,2

1.3

19

9

Many years

2,1

23

Source:

A: Doi Cu Meteorological Station (1977-1991)

B : Bao Loc Station (1981-1990)

C: Lien Khuong Station

Table 7: Wind Frequency According To Direction

Wind drirection

Frequency (%)

Windless

28,9

North

1,3

North-east

16,9

East

21,4

South-east

6,6

South

1,5

South west

4,7

West

11,6

North-west

7,1

Source: Lien Khuong Station (1995)

Other weather phenomena

In Lam Dong, there has other weather phenomena that should better note such as fog, salt flog, rain, thunderstorms and hail, but these phenomenon is not periodic(Table 8).

Table 8: Monthly Average Number Of Cloudburst And Foggy Day

Month

Cloudburst day

Foggy day

Da Lat

Lien Khuong

Da Lat

Lien Khuong

1

1

0

6

0

2

1

1

9

0

3

4

4

13

0

4

11

7

16

0

5

11

21

9

2

6

8

26

4

0

7

8

23

6

0

8

5

20

4

0

9

9

4

8

2

10

5

14

6

1

11

2

1

3

3

12

1

1

3

0

Many years

66

122

97

8

Source: Doi Cu Meteorological Station (1977-1991) – Lien Khuong Station

Fog

Low temperatures, especially during the night and early morning, the water vapor in the air easily reach the saturation so fog occurs in Lam Dong more than in delta

The area around forest appears more fog than the central hills. In the valleys, due to wet, cold and tight wind, fog covers longer than the high, airy places.

Salt flog

In Da Lat, salt flog usually occurs in January, February. In March there may have salt flog but slight. Salt flog cause great harmfully to plants .

Cloudburst

In the first two months of the rainy season (April, may), rainy time is almost afternoon, it is usually cloudburst

Yearly, the number of coudburst day in Lien Khuong is more than Da Lat.

Hail

Hail is a special form of ice rain. Hail occurs during the heat period of year. In Da Lat hail usually occurs in April, May and June, especially in first two months of the rainy season

The size of the hailstone is depended on the conditions of its formation. Usually, big hailstone is as pea, in some cases, it is larger but not much

Hail rarely happens but in case of happening, it courses many damages to agricultural production, mainly mechanical break on plants, especially trees, vegetables. Hail distribution is depended on terrain and surface conditions. In mountain side with breezes and airy can occur more hail than in the valley

LAM DONG PORTAL
Management agency: Center Manage electronic information, of the Department of Information and Communications
Main responsible: Mr. Nguyen Viet Van - Director of Department of Information and Communications
Address: 19 Le Hong Phong, Ward 4,Da Lat city
Tel: 063.3545579 - Fax: 063.3545455 - Email: contact@lamdong.gov.vn
Write www.lamdong.gov.vn using the information on this website
FSC Company