Mekong river information and relevant websites

This report represents information of one of the largest river in Asia, Mekong River. It is also one of two important system rivers in Vietnam. Besides, the report is also introduced some relevant websites as well as some organizations which related with the Mekong River.

http://cantho.cool.ne.jp/ The Mekong Delta is a mega-delta with the area of 49,520km 2 , located at the end of the Mekong River. This wetland which has complicated rivers and cannals are well known as the world's storage of granary, especially of rice. The land is generally thought as the fertile soil, however, most of the areas have sever problem for farming due to delta's geological history. Actually, the area was once under the sea and the influence still remains in the soil as Acid Sulphate Soil. Delta's flat topography has boosted highly land-use, and the population density is also high. The Mekong Delta is now facing to many urgent problems for sustainable development such as decrease of Mangrove forests, annual flood in the rainy season and saline intrusion at coastal area, and etc. <BACK ^TOP Copyright© MDVN, All Rights Reserved http://cantho.cool.ne.jp/ameder/ It is difficult to collect appropriate information when we research specific overseas region. In the case of the Mekong Delta, even some basic figures are not so clear, and it might be common problem in international issue including developing countries. Meanwhile, if we can use local materials, the possibility of one's research might be widen, althogh we have to pay enough attention to its accuracy. MDVN manages this on-line project, AMEDER (Assistance for the Mekong Delta Researches) with the aim of providing useful materials like Maps, Pictures, Data, Links, for research use. In addition, MDVN itself discloses specific topics on the Mekong Delta. I hope AMEDER can be support for not only any kinds of researches in the Mekong Delta but also the sound development of this beautiful wetland. Please read notice board carefully when you want to use these materials for your own use. Map Thematic maps / Blank maps Graph & Table Graphs related to raw data Photo Pictures possesed by MDVN Reference Available documents / Local documents Link Useful on-line Web links <BACK ^TOP Copyright© MDVN, All Rights Reserved Mekong Delta in Viet Nam - http://cantho.cool.ne.jp Rivers in the Mekong Delta Structure and characteristics of rivers Contents 1. River system in Mekong Delta 2. Longitudinal Section of Two Main River 3. Erosion (Pleae wait a while) 1. River system in Mekong Delta As the former chapter, Lower Mekong Delta has many branches originated from two main stream of Hau River and Tieng River. These streams have carved by the tractive force of natural water flow. In addition, there are huge number of canals that have been constructed with purposes of irrigation, drainage, water- way, and guerilla sweeping. This canal system has developed quite well and almost all the place in Mekong Delta might be connected. Here, however, the system means natural river. The below chart is the location map of major rivers and its estuary in Mekong Delta based on some maps published in Viet Nam 4) 5) followed by a explantion according a report 6) . Fig. Major rivers and estuaries in Mekong Delta The Hau River (Bassac River) come from Cambodia to Viet Nam and keeps its name until the South China Sea. The Hau River meanders again and again from Phnom Penh to An Giang Province, Viet Nam, and the main flow follows a fault whose direction is the Northwest to the Southeast. The Hau River flows on a parallel with the Tien River which has larger scale than the Hau River. From Chau Doc to the South China Sea, the Hau River has completely straight shape because of a fault. After passing the Vam Nao Channel (or River), which connects the two main river at Cho Moi, the unbalance of the flow are dissolved, and the river width becomes expanded. Besides the channel, there are uncountable natural and artificial canals network between the two main rivers. The Hau River has two estuaries, Dinh An and Tran De, while Bat Sac, no longer was also an estuary of Hau River and is still one of the nine heads of the Mekong Delta. In the mean time, the Tien River (Mekong River) also comes into the border of An Giang Province and Dong Thap Province from Cambodia territory. From the uppermost delta to vicinity of My Tho City, the river shows bow-like shape due to a fault which is an imprint of geological joint movement. Each branch at lower Mekong Delta has been influenced with the fault followed by Hau River and another faults run from Ca Mau to Tan An which has a direction from the Northeast to the Southwest. Thus, the Tien River has complicated shape. The section from Ben Dinh / Tan Chau to the north of My Thuan, the Tien River meanders and repeats divisions and concourses; therefore there are so many sandbars or islands within the river. The cause of this complicated shape is attributed to faults. From Ben Dinh to Long Thanh, the Tien River flows according to the fault and the riverbanks in this section are severely eroded. From Long Thanh to the south of Cao Lang, the river meanders widely and defined three major faults. Near Phu Loi, the river was separated to three flows with Cai Vung Island and Long Khanh Island (refer the figure), and the northernmost flow are largely bent by two faults. From Phu Binh to Cho Moi, the Tien River is divided into two flows by Tay Island. The Northeast flow follows a Nortwest-Southeast fault and has a straight shape. On the other hand, the Southwest flow provides water from the Tien River to the Hau River through the Vam Nao Channel which is on a Northeast-Southewst fault. The Tien River also has two flows in the section of Cho Moi-Con Lan. The west flow follows a fault originally located from Hong Ngu to Cao Lan and has straight shape, while the east flow has bow-like shape. From Con Lan to the Southeast of Cao Lanh, Tien River is divided into four flows and has Chai Island and Tre Island. The river in this segment has had a tendency to move toward the South, and the oldest flow is Cao Lanh Canal. From here to Binh Hung, the river is single stream and has a movement to the North. From Binh Hung to the North of My Thuan, the river has two main streams and has a movement toward the Southwest. The area just upper side of Sa Dec are heavily eroded and the area has been expended to upper 200m against the city. From the point which is about 15km west to Vinh Long, the Tien River breeds many canals and the river is divided into the Co Chien River and the My Tho River (or Tien River) at Vĩnh Long City. The under picture was taken at My Thuan Bridge near Vinh Long City and shows separation point of Co Chien River from Tien River. Pic. Separated point of Co Chien River from Tieng River at My Thuan Bridge, Jan. 2003 After that Tieng River produces Ham Long River and Ba Lai River which enclose Ben Tre Province (like an island). Tieng River itself change its name to My Tho River at My Tho City although local people still call the river is Tieng Giang (Tieng River). And in the end, Tieng River subdivided to Dai River and Tieu River which mean Big River and Small River respectively and flow into the South China Sea. The chart above also has nine mouth corresponds to heads of the dragon. The information form the Museum of 9th army at Can Tho City and the dragon legend based on real nine estuaries. However, as mentioned above, Cua Bat Xac and Cua Ba Lai no longer show clear figure of mouth because of long- term sedimentation, therefore Mekong River has seven big estuaries at the end of the flow in reality. But the Vietnamese lucky number of nine still be used to describe the delta. The head word of each estuary, "Cua" means "door" so could be translated to "mouth" of the river. The under picture was taken at the Cung Hau Mouth, the point where Co Chien River pour into the South China Sea. Pic. Cung Hau estuary, the mouth of Co Chien River at Long Hoa, Tra Vinh Province, Feb. 2003 Thus when we overview the river system without artificial canals, Mekong River could be divided to main stream. Hau River has single straight shape and provides water mainly to the west side of Delta. Tieng River has some major branches and act as a main water pipeline to east side of Delta. You can see some pictures of rivers in Mekong Delta. 2. Longitudinal Section of Two Main River So far regular systematic survey of each river in Mekong Delta hasn't been carried out. There is an vertical shape of two main river although the detail of survey is not clear 2) and you can see the image of this with revised chart. The original chart has no data (value) and is described with plain and vertical section like this. According to original figure, the survey seems to be done each 1-2 km span. The simplified chart here shows a hypothetical bed slope which is based on average depth in each 40km span. First, the Tieng River's inlet for Viet Nam from Cambodia is about 240km upper from its mouth, and this uppermost segment has near 40m in maximum depth and the segment is also deepest one through the whole Tieng River on the point of average depth. From uppermost segment to just upstream point of My Tho City, water depth fluctuate within a range of 5-20m and decrease its average depth gradually. The point 80km upper side from the sea record some 30m depth and from this point to the sea, most section has 10m or below depth. When the river reaches to its mouth, the depth becomes only 3m or thereabout. On the other hand, Hau River has about 200km length in Mekong Delta. From the uppermost point, Châu ÐôLc City to Long Xuyên City, the water depth repeats wide fluctuation from 5 to 30m and it turns shallow gradually. Near Can Tho City, which locate on 100km point far from the sea is the deepest section but Tieng River is more deeper. And then the river bed is lifted as the river going down and finally, there is 5m depth at the estuary. Consequently Tieng River lose its depth at downstream section due to separation of branches while its upstream section have relatively rich water depth. In reverse, upper section of Hau River is not so deep and wide but its middle and downstream section has more depth compared with Tieng River. This figure from unclear original has not enough confidence for official use but this still shows us relative shape of two main river in Mekong Delta. And we also have to consider tidal affection which has some 4m difference between high and low tide or seasonal difference between rainy season and dry season. Mr. Hori mentioned an interesting story about My Thuan Bridge which have constructed over Tieng River in his book 1) . The bridge constructed by Australian ODA after long term investigation is a part of National Road No.1 and this connects Tieng Giang Province and Vinh Long Province. This bridge was planned with extremely high clearance because Cambodian Government inisted on the importance of navigation for large vessels from the sea to Phnom Penh. But actually, estuaries of Tieng River has only 2m in dry season or 3m in rainy season, therefore that argument has no persuasion in reality. The most recommended route is combination of two main river, from Hau River via connection canal at An Giang Province to Tieng River and the route supports characteristics of two main river on the point of water depth. 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and inundations in the Mekong Delta <<< H%C(&/%( &C.<* &N>/H6 /(/CH* I(66&GGGG&IH*F& 6GG(/6&6GG  4 *5(&HG G*%C&/H>C I* The classication of ood in the Mekong Delta 2 5  % 0 1 6 M&!&  M6 F &.L 7 B 6 !&!( 1 ( &6 !&!( [...]... Basic figure of the Mekong River 3.1 Area 3.2 Length and inclination 1 Geographic Review The Mekong River is one of the world's 10th rivers in its river length and has great influences upon nature and societies of the Indo-china Peninsula The name "MEKONG" originate in Thai language, Mae Nam Khong1) The source of the Mekong River is in Tibet mountains and is called Dza Chu River (River of Rock) After... the Mekong Delta Name Mekong River Commission Mekong Project Development Facility Address http://www.mrcmekong.org/ http://www.mpdf.org/ Eng Jap Viet Ο × Ο Ο × × Mekong Research Mekong Sources Mekonginfo South East Asia Rivers Network Asian Disaster Reduction Center International Rivers Network Vietnam Development Information Center Viet Nam Red Cross Sustainable Development Vietnam http://www.mekongresearch.com/... run through the border of Laos PDR and Thailand 4) Take some right tributaries from Thailand and then run into Cambodia 5) Take some right tributaries including Tonlesap River from Great Lake 6) Start breaking up into plural flows and form vast Mekong Delta in Viet Nam and finally run into the South-China Sea 2 Countries in the Mekong River basin This complicated flow and relationships between each country... 向かう．このトンレサップ湖がメコンデルタの洪水と乾季の流量配分に及ぼす影響は非常に大 きいため，簡単にその概要を整理する． The Mekong River running through the Indo-China Peninsula is the representative mega -river in Southeast Asia The basin originate in Tibetan mountains of China, and includes other five countries, Myanmer, Laos, Thailand, Cambodia, and Vietnam The area of the Mekong River is about 795,000km 2, and the extent corresponds to more than two-times of Japanese land area The main stream... reorganized to interim one without Cambodia and then MRC (Mekong River Commission) undertake the task independently against UN Present members are Viet Nam, Thailand, Cambodia, and Laos followed by China and Myanmar as observers Now their biggest theme is sustainable developing of the Mekong River The data 2) of each MRC country are below; Table- Countries in the Mekong River basin Nations Area (km2) Basin... Jiang and Salween River, the Mekong reach to Yung-Nan Province of China and is called Lancang Jiang (Turbulent River) Via Golden Triangle, the crossing of China, Myanmer and Laos boarder, the Mekong flow into Vientiane Plain The term, Lower Mekong means downstream segment from the point There are some notorious rapids for French navigation plan in colonial period before the Mekong get to Cambodia, and. .. Regarding China and Myanmar, the Mekong River carves not so much part of each country Thailand has some areas of the Mekong River over the Kholart highland which located east part of the country And not only the Mekong Delta but also some small basin in south-central mountains which run into Cambodia belong to Viet Nam These countries constitute the Indo-China Peninsula and at the same time, they have... slender (2) Length and inclination Below is a sketch of longitudinal figure of the Mekong River The altitude data at each points was collected from several sources or was counted backward from its inclination in a span so this is not a rigid information However this picture might help you understand the Mekong River' s topographical figure Figure- Profile image of the Mekong Delta The last and lowest point... Thailand 513,115 184,240 Cambodia 181,100 154,730 Social Republic of Vietnam 331,700 65,170 Ratio 1.7% 3.5% 85.5% 35.9% 85.4% 19.6% In Laos and Cambodia, approximately 85% of national area corresponds to the basin of Mekong River, therefore these countries have pretty deep relationships to the river Both of capitals, Vientiane and Phnom Penh have the Mekong River in its central part Regarding China and. .. Mekong River Table- Basic figure of the Mekong River Items Value 2 795,500km ifrom 'Mekong River - Development and Environment' Catchment Area Hiroshi Horij River Length 4,620km (same above 4,880km in a report of ADB) Highest Point 4,968miat a pass of Tibet, Rupsa laj 53iat Crache, Cambodia) the ratio of [max flow in a year/min flow in a Flow Coefficient year] (1) Catchment Area Catchment area of the Mekong . the river is Tieng Giang (Tieng River) . And in the end, Tieng River subdivided to Dai River and Tieu River which mean Big River and Small River respectively and flow into the South China Sea. The. Lang, the river meanders widely and defined three major faults. Near Phu Loi, the river was separated to three flows with Cai Vung Island and Long Khanh Island (refer the figure), and the northernmost. Mekong River $* $*"M 1. Geographic Review The Mekong River is one of the world's 10th rivers in its river length and has great influences upon nature and