[精品论文]Planning on soil utilization for the Coastal Mekong River.doc

精品论文planning on soil utilization for the coastal mekong riverdelta, viet nam in period 2005-2010tran thai hung1 2 *，xing wengang1，le sam2，vu thi thu nga31. agricultural engineering department，hohai university，nanjing （210098）china2. southern institute of water resources research，ho chi minh city，vietnam3. college of economics & management，nanjing agricultural university，nanjing（210095）chinae-mail：abstractthe coastal mekong river delta, viet nam includes 8 provinces: long an, tien giang, ben tre, travinh, soc trang, bac lieu, ca mau and kien giang, it is the multiform ecology with many production industries: agriculture, forestry, aquaculture, salt this is really a region with advantages and private features about geography, natural conditions and resources, water and soil environment, manpower and multiform economic potentiality of mekong delta in particular and vietnam in general. however, these potentialities have not been exploited equivalently to its statue, because in there it still has existed unstableness and implicit hazards caused by natural calamity. to direct suitable exploitation and multiform development of economic components with a position of agriculture-forestry and aquaculture strength, adapting to natural ecological environment in this region, we need establish planning on soil utilization basing on researched results of salinity intrusion and water environment, peoples material and moral welfare in the whole area to determine the suitable, long-term and stable plan, and to help an important part in achievement of economic-social development following rural industrialization and modernization direction, raising peoples living standards in the coastal mekong river delta to the new level.keywords ：reality and planning on soil utilization ，developmental orientation of economy andsociety1. natural features1.1 geographic location:the coastal mekong river delta is about 2,86millions hectare in area (8.4% compared to vietnam), including 8 provinces: long an, tien giang, ben tre, tra vinh, soc trang, bac lieu, ca mau and kien giang. this is the last part of the mekong delta, it has two sides bordering of the sea with more than 700kilometers long of coast.1.2 topographyhere is the level alluvium with many low depressions and it reduces the height of terrain fromnorth-west to south-east in general trend. average elevation: 2 meters high.1.3 climate featuresclimate in the coastal mekong river delta is monsoon climate, it is divided 2 absolute seasons, rainy season: from may to november and dry season: from december to april of next year.14table 1: climate features of the coastal mekong river delta.total annualaverage precipitation (mm/year)daily average temperature (0c)total annualaverage evaporation (mm/year)dailyaverage humidity (%)total annualaverage of sunny time (hour/year)total dailyaverage radiation (cal/cm2/day)wind average (m/s)1300 2400max: 31 33min: 23 25880 - 124080 - 842200 - 2600370 - 4901 - 5- 7 -source: the southern hydrological station, vietnam, 2005.1.4 geology: there are 5 main kinds as1) peat dome u minh forest2) holocene bracket water marine deposits in depression area3) pleistocene alluvial deposits4) granite hills and mountainous area5) holocene fluvial deposits, complex of levees and backswamps. 61.5 soilsmain soils are in the end of holocene period as entisols, inceptisols, ultisols, histosols.table 2 distribution area of soils in the coastal mekong river delta.orde rtype of soillongan(ha)tiengiang(ha)bentre(ha)travinh(ha)soctrang(ha)baclieu(ha)camau(ha)kiengiang(ha)totalarea(ha)compared tototal natural area (%)1sandy soils3,6853,56214,24816,6474,175452671043,4401.522saline soils42,03535,75998,73962,433145,084101,850214,702113,216813,81828.433acid sulphate soils231,96746,75115,25328,68168,155141,384279,974365,3151,177,48041.13potential acid sulphatesoils87,85011,2373,41213,75415,03631,073198,68931,442392,49313.71active acid sulphatesoils144,11735,51411,84114,92753,119110,31181,285333,873784,98727.424alluvial soils74,666131,63366,47193,54183,0615,0640118,394572,83020.015peat bogy soils0000008,69810,84319,5410.686gray soil84,3320000002,53486,8663.037eroded soils000000010,55710,5570.378river, canal12,50218,95836,79121,26521,8555,44115,4626,045138,3184.83total natural areas (ha)449,187236,663231,502222,567322,330254,191519,507626,9032,862,850100(source: southern institute of water resources research, vietnam, 2005.) 61.6 hydrogeologyunderground water is very plentiful, it is filled with deposits of holocene, pleistocene, pliocene, miocene, sand and rock rifts. however there are many underground water area being infected by salt so good reserve is limited and distributed unequally. this is the underground water type with additional source. 1, 141.7 hydrological regulationsit is powerfully influenced by tide, rainfall, but at the same time it is also governed by the mekong river flow but it is not strong. the east coastal area from can gio to ca mau cape is influenced by the south china sea, it is the unequal semi-daily tide, the water sea level goes up andgets down two times daily, it has two tops and two bottoms, the amplitude is from 2.5meters to3.5meters high. the west coastal area from ca mau cape to ha tien is influenced by the sea of thailand gulf, it is the mixed daily tide, it has two tops and two bottoms but the big fluctuation predominates, the amplitude is from 0.7meter to 1.0meter high.river and canal systems are very plentiful and connected together, therefore the flow regulation is also influenced by the mekong river flow and interior field rainfall, and it makes flow regulation with two distinct seasons: dry season and flood one. saline intrudes interiorly by the river and canal systems connected to the sea. in the rainy season, it depends on plentiful clean amount by rainfall and the mekong river so saline boundary is pushed back to the sea, but clean water dischargereduces in the dry season therefore saline intrudes interior again. 1, 2figure 1: location of the mekong delta, vietnam.(source: southern institute of water resources research, vietnam, 2005.)figure 2: location of the coastal mekong river delta, vietnam.mekong delta soil distributionalluvial soilsalluvial soilssaline affected alluvial soilspotential acid sulphate soilsactual acid sulphate soilssand-ridgesother soilssaline affected alluvial soils potential acid sulphate soils actual acid sulphate soils sand-ridgesother soilsfigure 3: mekong delta soil distribution. 6(source: southern institute of water resources research, vietnam, 2005)2. economic and social realitythis is the region where has been exploited and developed more slowly than central ones of the mekong delta done. most of countryside except some cities and townships in the coastland are remote regions with weakness and shortcoming infrastructure, difficult traffic, weak of water for serving life and environmental sanitation, medicosocial task is less. culture, society and education here have been developed more slowly than other regions done. peoples income is low. 13main economic industries in the coastal mekong river delta include: agriculture, forestry, aquaculture, exploitation and production industry of constructional material, aquaculture and agriculture process industrywith agricultural area is 1,530,667hectares (53.50% total of natural area), here is the region with the biggest agricultural production area of vietnam. in ten years (from 1990 to 2000) agricultural soil was extended 507,620hectares more, it was concentrated in period before 1998. increase and utilization of agricultural soil area effectively has helped to hasten production speed and agricultural productivity. achievements have got 40% national agricultural produce, 50% national rice produce,60% national fruit produce. 9with more than 700kilometers long of the coast, the coastal mekong river delta is the biggest aquaculture area of vietnam. total aquaculture area is about 596.584hectares. aquaculture industry has broken through considerably for years. area, productivity and yield increase daily. because shrimp culture has made effect higher than rice cultivation so locals are changing some agricultural area to aquaculture or aquaculture combines with rice cultivation. 9following statistical result in 2005, the mangrove forest area in the mekong delta is 95,760 hectares. now the whole of mangrove forest is young states with under twenty years old, in there from70% to 80% total area of current mangrove is forested and cultivated combination with aquaculture, natural forest area is only 20%. locals are trying to intensify the mangrove forest rehabilitation now. 6the road traffic network is undeveloped, especially the countryside road quality is very bad, they are mainly soil roads so they restrict on exchanges between internal regions and outside ones. in the flood season, (average flooded depth is from 0.8meter to 1.5meters, flooding period: aug. nov.), traffic and transportation at deep flooded regions are very difficult. total national and provincial road is about 2,000kilometers long, suburban one is 3,000kilometers long. the whole river and canal system have been utilized for traffic and transportation. big rivers and canals have been utilized for inter- provincial and inter-regional traffic.hydraulic project systems have been built many to serve irrigation and drainage, prevent salinity intrusion, cleanse alum soil and operate serving production effectively. however in the exploitation process, these systems have not managed, maintained and upgraded overall and irregularly, therefore adjustable abilities have not satisfied requirements made, there were many regions with salinity intrusion to interior field, it influenced crop productivity in the dry season, conversely in the flood season it is flooded seriously. in five years there were 105 big projects built, in which 60 projects have completed. 3, 8, 10now population in the coastal mekong river delta is about 12.5millions people, it is 14% ofvietnam (2004). in there countryside occupies 84.0%, citizen is 16.0%. average population density is320people/km2. people distribution is not equal. most of people are ethnic vietnamese, some of them are khmer and chinese. here is the area where has the highest khmer rate in the mekong delta. 123. planning project of soil utilization in period 2005-2010.3.1 scientific bases to make the planning project1.the basis of the salinity intrusion process in period 14 years (from 1991 to 2004). 2, 4, 15;2.the basis of the soil resources. 6;3.the basis of distribution and development of the coastal mangrove forest. 6;4.the basis of agriculture and aquaculture development potentiality. 7;5.the basis of setting up the adaptable map for water and soil potentiality utilization. 11, 123.2 developmental targets- annual gdp rate grows over 9.8%/year, in there agriculture, forestry and aquaculture productions achieve average 6%/year.- average income achieves over 550usd/year.- there is no hungry household, poor household rate reduces to 10% leave, from 70% to 80% households are supplied electricity, from 75% to 80% city households and countryside ones get clean water utilization.- invest and complete for building infrastructural systems and population groups suitably with the whole area general planning.- improve and raise peoples living standards, especially for khmer people (there are a lot ofkhmer people in tra vinh, soc trang and kien giang provinces). 11, 123.3 developmental contents* develop the multiform and effective agriculture:rice cultivation is still an advantage of the coastal mekong river delta. strive for increasing crop and cultivation area, and stabilize area with active irrigation and drainage conditions to produce two certain crops. strive for achieving from 10millions to 10,5million tons/year of rice productivity in2010.develop plant for industrial material as maize, soybeans, sugar-cane, coconut, cotton develop fruit-tree with advantage competition and highly economic value as: mango,tangerine, orange, grapefruit, durian, star-apple, pineapple. strive for achieving 180,000hectares of fruit area in 2010.develop breeding domestic animal and poultry to satisfy inland and export, increase milk cow to supply material for milk process factories in long an, can tho and other provinces. 11, 12* develop aquaculture:develop aquaculture strong in the whole water source types (freshwater, sea and brackish water). step by step develop to culture shrimps, fishes and mollusca with high economic value in sea following general and every local region planning. multiform of culture: interposition, alternation, specializing, intensive culture, semi-intensive culture, ecological culture strive for achieving735,000hectares of aquaculture in 2010, in which there will be 590,000hectares of culture in sea and brackish water.priority must be given to build the infrastructure system for aquaculture, especially hydraulic projects, take form culture project regions with medium and large scale to be invested comprehensively, guarantee the requirement for developing stably and highly effective.enhance investment to develop deep-sea fishing with high power and modern fishing-boats. forbid utilizing fishing-boats with exterminatory and exhausted catching equipment to protect the deep-sea aquaculture resources. 11, 12* develop forestry:forestry in the mekong delta makes up not high proportion to national economy but it has an important effect on defending and protecting environment, restricting the coastal and river mouth erosion, balancing ecology in this area. therefore rehabilitating and developing the defending feature, protecting ecological multiform feature of forest are an important life-and-death object of the coastal ecosystem protection. strive for raising the forest cover in the mekong delta over 15% of the total natural area. 11, 12*develop infrastructure:develop infrastructure including hydraulic, traffic and transportation system, cultural and educational projects, health and public ones as markets, trade service and administrative centre build the electrical network system strong. supply and guarantee 100% of households getting clean water forlife.develop the traffic and transportation has the decisive signification on economic and social development, especially for rural one. building the road system helps connecting through to districts, industrial and export processing zones, commune centre and population groups in countryside combine the dike system to constitute road through along the coast for serving the peoples welfare and national defense.with the waterway traffic, general direction is the rehabilitation of inter-regional and inter- provincial traffic line, combine irrigation and drainage canals to constitute waterway traffic systems and guarantee for ships with the load from 10tons to 20tons moving conveniently. develop small harbors and wharf systems along the waterway line to make advantage for transportation to countryside.build full-done hydraulic systems including active irrigation and drainage projects, cleanse alum soil, control salinity intrusion and satisfy the stably developmental requirement of agriculture, forestry and aquaculture production. control flood synchronously from clue project to lower branch canals and interior system, ensure for safe production and peoples stable life. combine with traffic industry and other ones to guarantee peoples normal activities in the flood area. 10need early raise, develop river mouth and sea dike systems because they have very important signification for production protection and development, peoples life, national defense and environment in the coastal area. 8* plan population:aquaculture industry of breeding and catch is being developed strong, it will impulse urban development because from there it will be opened harbors, wharves for fishing boats to get in and transport goods to domestic and outside area, and it also will be opened process factories of aquatic and forest product. the production development following industrialization direction also impulses development of trading services. besides, tourism potentiality and exploitation capacity of gas and oil in the future will contribute for urbanizing development in the coastal mekong river delta.the urbanizing rate in the coastal mekong river delta in particular and mekong delta in general is rather low compared with the whole of vietnam. basing