the historical flood in 2000 in mekong river delta

Geographical Review of Japan Vol. 80, No. 12, 663-680, 2007

The Historical Flood in 2000 in Mekong River Delta, Vietnam:

A Quantitative Analysis and Simulation

Le Thi Viet HOA*, HARUYAMA Shigeko*, Nguyen Hun NHAN**, Tran Thanh LONG**, and Bui Duc LONG**

* Institute of Natural Environmental Studies, Graduate School of Frontier Science, University of Tokyo, Kashiwa 277-8563, Japan

** National Hydro-Meteorological Center, Ministry of Natural Resource and Environment, Vietnam

Abstract: The Mekong River Delta is one of the world's largest deltas and plays an important role in Vietnam's economic development. Studies of flood propagation over the whole delta have been rare. In 2000, due to global climate change and La Nina phenomenon, the hydrological and meteorological situations were very complicated around the world in general, and in the Mekong River basin in particular. In Mekong Delta, flood occurred early and had two peaks in which the second peak was one of the highest in the past 80 years. This flood caused water levels in the upstream Mekong River basin to become about 1 to 3 m higher than the third warning level, and caused extremely severe inundation downstream. In Vietnam, this flood caused damage totaling about 5,000 billion VN dong (about 4 million US dollars at that time), and its level was used to consider the design elevation of flood control embankments. Thus, through study of this flood is necessary to mitigate flood damage and human suffering and to contribute to policy making and create the conditions for embankment elevation design.

In this paper, analysis of the main characteristics of the flood of 2000 was carried out based on the observed data since 1926. Also, simulations were conducted using hydraulic models with topographical, hydrological and meteorological data. The flood simulations using hydraulic model

for Vietnamese part of delta were carried out, especially for Dong Thap Muoi and Long Xuyen

quadrant to analyze (1) how the flood was distributed spatially and temporally, (2) how long each inundation depth lasted, (3) the extent of the area of the flood, and (4) the effect of flood on

paddy fields in 2000. The observed data and simulated results show that this flood was extremely large and complicated, causing severe inundation with the depth of 2.5 m lasting more than one month from mid-September to mid-October. Flood in August affected strongly the summer-au-tumn crop paddy field. The area inundated to the depth of 2.5 m was more than one thousand km2.

Key words: Mekong River Delta, flood, simulation, hydrology, hydraulic model

Introduction

Floods are common natural hazards occurring all over the world, causing loss of life and prop-erty each year. An increasing trend in extreme flood events can be observed in many countries

around the world in general, and in the Mekong River Delta in particular. It is rare for big floods to occur successively as they have occurred since the end of the last century, in 2000, 2001, and 2002, with peak values exceeding 4.7m at Tan Chau (location is shown in Figure 1c),

whose level is considered to correspond to se-vere inundation in the delta (Huynh 2002).

The Vietnamese part of the Mekong River is lo-cated at the farthest downstream end of the Mekong river basin. It is a flat and low-lying area

of 4.95 million ha and occupies about 11% of the whole basin (Mekong River Commission 2001). The Mekong River Delta in Vietnam is affected by two tidal sources, the regular semi diurnal tide from the South China Sea and the irregular diurnal tide from the Gulf of Thailand. The ef-fect of the former, whose highest amplitude of fluctuation is about 3.5-4.0 m, is stronger than

-663-

166 HOA L. T. V., HARUYAMA S., NHAN N. H., LONG T. T., and LONG B . D.

that of the latter, whose amplitude is 0.8-1.0 m

(Truong 2006). These tidal effects on the flood-ing in the Mekong River Delta are complicated and caused long lasting inundation at the end of the flood season.

The flood of 2000 was considered to be a his-

torical catastrophic flood in this area. According to data from Vietnam's National Flood and Ty-

phoon Prevention and Preparedness Committee, the damage caused by the flood of 2000 in Viet-

nam was very significant. It cost about 5,000 bil-

lion VN dong (about 4 million US dollars at that

time). In accordance with the decision 173/2001/

QD-TTG of November 6, 2001 of the Prime Min-ister, the historical flood event in 2000 elevations

were chosen to design the future embankment

planning in the Vietnamese part. Thus, it is nec-essary to understand the 2000 flood in detail.

A flood event is characterized by the volume

of runoff, peak discharge, time of rise and dura-

tion, depth, velocity, and extent of the flooded

area. Therefore, floodplain management is better

Figure 1. (a) Location map of Mekong River Delta, the arrow points to the region in which inundation is analyzed in Figures 6,7, 9 and 11; (b) The model network grid for computation; the darker parts show the Dong Thap Muoi area and Long Xuyen quadrant; (c) Hydro-meteorological network.

-664-

The Historical Flood in 2000 in Mekong River Delta 167

Figure1.(c)Figure1.(b) -665-

168 HOA L. T. V., HARUYAMA S ., NHAN N. H., LONG T. T., and LONG B . D.

done with GIS, linked to hydrological and hy-draulic modeling, using GIS-based hydrological analyses (Vieux 1991; DeVantier and Feldman , 1993; Correia et al. 1998; Jamn and Singh 2005)

However, for a large delta such as Mekong River Delta, observed dataa are not detailed

enough in microscale regions, leaving the knowl-edge of the origins of flooding and its possible magnitude in a given region still unclear. There-fore, it is necessary to couple a hydraulic model

and GIS to simulate flood flow to understand the hydrological regime in this delta.

The flood in 2000 has been a major topic of study. Kazama et al. (2002) studied the flood of 2000 by numerical simulation and conducted a field survey in an area 100 km from east to west and 150 km from north to south around Phnom Penh. This study showed the inundation distri-

bution in the Cambodian part of the Mekong Delta. Damage according to field survey in Viet-nam was reported by Kazama (2001). Hagiwara

et al. (2002) studied the change of inundation area under various controlled flood situations and irrigation by using numerical simulation in one limited downstream part of the lower Mekong basin in Cambodia. The study found that the wide area of inundation in the lower Mekong

is reduced by flood control, and traditional irri-

gation style becomes impossible in some regions. Geographical features and land use around Phnom Penh, Cambodia was studied by Kubo

(2006), and geomorphology research in corre-spondence with flood 2000 and geographical fea-tures of Dong Thap Muoi in Vietnam was stud-ied by Umitsu et al. (2004). These studies were not for the whole Mekong River Delta in Viet-nam, therefore, the flood of 2000 of such long in-undation period should be simulated by using a numerical model for the whole delta.This will help the further understanding of the 2000 his-torical flood.

In the Mekong River Delta, flood propagation

models in rivers and floodplains with models solving the Saint Vennant equations were devel-oped (Dac 1996; Nien 1996; Dong 2000). The first flood model was developed in the 1960's by SOGREAH (SOGREAH 1963). The large scale and the complexity of the problem made this model famous and well known worldwide for some decades. However, this model was still in-

capable of simulating accurately the flood flow in the Vietnamese Mekong Delta. The modeling scheme had to be fundamentally changed due to new canals, dikes, and roads developed in the flooded areas. Since then, other hydraulic mod-els have been applied to simulate floods: e .g., MIKE 11 developed by DHI-Water and Environ-ment, Denmark recently was applied as an analy-sis tool for a study on the Tonle Sap flow; ISIS developed by HR Wallingford and Halcrow was

used to simulate the river system downstream of Kratie, but at present there are insufficient data to warrant setting up the model (Mekong River Commission 2004).

In Vietnam, topographical and hydraulic data on the delta have been updated since 1978, and various one-dimensional hydraulic models have been developed by Vietnamese scientists: e.g. SAL (Thuy and Dac 2000), VSARP (Doug 2000), KOD (Nien 1996; Nien et al., 2004, Lanh and Minh 2004). All these models are based on the

one-dimensional Saint-Vennant equation, but dif-ferent methods are used to solve the equation. The complexity of river network density, em-bankment systems, sewer systems, etc., can cause certain problems for each model. The local models have produced better simulations of the

flooding situation in Vietnamese Mekong River Delta, however, without GIS linking, most of

them are "unfriendly" and difficult to operate and to solve the data management problems. Drawing on previous basic studies and oriented toward application to Vietnamese conditions, the hydraulic model HydroGis was developed by our

group at the National Center of Hydro-Meteorol-ogy. Of the local models, HydroGis takes into consideration the effect of wind speed and salin-ity. It has the further advantage that by linking with GIS, the model can visualize the results, and manage the database efficiently. Through this combination, we can easily analyze the results to better understand such problems as how serious the inundation was in each sub-region, the size of the area affected by each inundation, and its effects on the paddy fields.

Objectives

In this paper, flood peak water levels since 1926 at Tan Chau, Chau Doc (Figure la), which

-666-


are observational stations, were used to estimate

the frequency of occurrence of flooding in the

Mekong River based on Person ape III distribu-

Lion(Shahin et al.1993), and by combining them

with the observed data in 2000, the flooding

process in 2000 was analyzed. By using Hydro-

Gis model and topographical, hydrological, me-

teorological, and land use data in 2000, simula-

Lion and analysis of flooding in 2000 were car-

ried out to understand in greater detail(1)how

the flood was distributed spatially and tempo-

rally,(2)how long the inundation lasted at each

given depth,(3)how widely the flood spread, es-

pecially in Dong Thap Muoi and Long Xuyen

quadrant zones (Figure la), and (4) the effect

of flood on paddy field in 2000.

Method and Data

The HydroGis model was used to simulate the

flood of 2000 in the Vietnamese part of the

Mekong River Delta. This model couples a

numerical free-surface flow model and GIS tools

(Nguyen et al.2002;Nguyen and Tran 2003;Le

et al.2005,2006). The hydrodynamic model

includes an one-dimensional model with the fully

non-linear Saint-Vennant equations for river

flows, a two-dimensional model without inertial

terms in the momentum equations for flood-plain

cells;the infrastructures are modeled with the

energy.

In order to apply the HydroGis model for flood

simulation, it is very important to create a com-

putation network for the study area. The grid is

shown in Figure lb. The detailed computation

scheme for the Mekong River Delta in this study

includes 2,535 flooding cells,13,262 cross sec-

tions and 467 sewers, bridges, and sluices. At

each cross-section, width, depths at points and

corresponding distance intervals along the width

of the canals were input based on the data avail-

able from the Vietnamese Ministry of Trans-

portation's inland waterway administration from

1990to 2000. In every cell, maximum, minimum

and average elevations were digitized based on a

digital elevation model(DEM)with a resolution

of 100×100 m obtained from the Mekong River

Commission although the accuracy of the origi-

nal data is unclear. Border elevations of the

floodplain cells were digitized by data from

Southern Institute of Water Resource Investiga-

Lion and Planning. Information about changes in

dikes and embankment elevations are available

from local offices.

Hydrological data are available from the Na-

tional Center of Hydro-Meteorology of Vietnam .

There are 82 downstream boundaries located at

estuaries in which hourly water level data were

used and 7 upstream discharge boundaries with

daily discharge data. The daily rainfall, evapora一

tion, infiltration, and wind data were input from

archives of 24 hydro-meteorological stations in

the Mekong River Delta including some stations

in Cambodia such as Phnom Penh, Kratie and

Siem Reap(Figure 1c). The model runs in time

steps of 15 minutes.

Simulated water levels at several stations were

compared with observed data. Computed inflow

and outflow from Dong Thap Muoi and Long

Xuyen quadrant(Figure 1a)were also compared

with the values measured during the flood in-

vestigation by the National Center of Hydro-Me-

teorology. Validated results will be used to pro-

duce inundation depth and duration maps and to

analyze the inundation characteristics in Dong

Thap Muoi and Long Xuyen.

Results and Discussion

Analysis of characteristics of the flood of

2000based on observed data

From the beginning of July to August, the

tropical convergence combined with the strong

southwest monsoon and typhoon Wu Kong

caused large scale rainfall from middle and lower

parts of Laos to the Central highland, Cambodia,

and provinces in the Vietnamese part of the

Mekong River Delta, generating early and big

floods in July. Based on rainfall data from the

National Hydro-Meteorological Center, the an-

nual rainfall distribution in the Mekong River

Basin in 2000 is shown in Figure 2.

In July, flooding reached levels that were the

maximum of long-term average in this region

(Figure 3). The water levels in the Mekong at

Kratie increased at a maximum rate of 105 cm/

day, but 11-15cm/day at Tan Chau and Chau

Doc stations, as shown in Table 1(locations are

shown in Figure lc). In the beginning of August,

-667-

170 HOA L. T. V., HARUYAMA S., NHAN N. H., LONG T. T., and LONG B. D .

Figure 2. Annual rainfall distribution in 2000 (in mm).

the first peak at Tan Chau (Mekong River) of 4.22 m on August 1St was 0.02 m higher than the

third warning level at which inundation becomes severe, threatening flood control structures or making these structures ineffective. Also, the

first peak at Chau Doe (the Bassac River) of 3.81 m on 2nd-5th August was 0.31 m higher than the third warning level. After that, flooding in the river slowly decreased but water levels in Dong Thap Muoi and Long Xuyen quadrangles continuously increased. In September, flood flow continued to increase and the second peak was

the highest of that year and occurred about 1 month and 21 days later than the first. Compared to the other two peak flood records, this differ-

ence is about 10-20 days longer. In 2000, at Tan

Chau, the flood peak of 5.06 m was the third highest since 1960, and at Chau Doc the flood

peak of 4.9 m was the second highest during the 80-year period since 1926 (Figure 4). It is un-

usual that both occurrences coincided, on Sep-tember 23rd

The water levels at most stations in Dong Thap Muoi reached the highest levels since 1960. The farther one goes downstream from Dong Thap Muoi, the higher the increase observed over the highest water level recorded in the past 40 years. At Tan Chau, the duration of water level higher

than 3.5 m was 118 days, the longest inundation

period since 1961, and again at Tan Chau the du-

-668-


Figure 3. Hydrograph of water level in Mekong River in 2000 (a) at Tan Chau; (b) at Chau Doe.

Figure 4. Mekong River flood peaks (a) at Tan Chau; (b) at Chau Doe from 1926 to 2004.

-669-

172 HOA L. T. V., HARUYAMA S ., NHAN N. H., CONG T. T., and LONG B . D.

Table 1. Comparison between flood 2000 and historical flood in Mekong River Delta (data source from Na-tional Center of Hydro-Meteorology in Vietnam)

Note:Imax-Maximum increasing intensity

Hmax-Maximum water level

△H-Difference between flood 2000 water level and historical flood water level

(Location of upstream stations are shown in Figure 1(c), Luang Prabang, Vientiane, Pakse are shown in Figure 2, Hong Ngu

is shown in Figure 6)

Table 2. Time period corresponding to high water level at Tan Chau (days)

ration of water level higher than 4.5 m was 34 days, similar to the floods of 1966 and 1978

(Table 2). The flood of 2000 is compared with historical

flood values at main stations on the Mekong River in Table 1. Although in upstream areas the

year 2000 flood water level did not exceed the highest historical levels, in the lower Mekong

River Delta, flood levels in 2000 approached or equaled the highest levels recorded in history.

This may be caused by the combined impacts of increased upstream flow, spring tides, sea-level

rise, and flood control structures. Based on the 78-year accumulated hydrologi-

cal data at Tan Chau and Chau Doe (from 1926

to 2004), the probability of a flood like 2000 was estimated using Person Type III distribution

(Shahin et al. 1993). Figure 5 shows the pre-occurrence probability of the observed flood

peaks occurring at Tan Chau in the Mekong River Delta. This flood has an occurrence frequency of about 5%; such an extremely large flood is wor-thy of study in detail using hydraulic models.

Analysis based on observed water levels at all

-670-


Figure 5. Probability of Mekong River flood at Tan Chau.

stations in the delta has not been done by pub-lished studies, which limited observations to flood flow in the rivers and canals. In order to understand in detail the mechanism of flood

propagation and inundation, HydroGis model is applied to simulate flood.

Flood simulation and analysis

Topographical, meteorological and hydrological data, including data on such flood control struc-

tures as sewers and dike elevations, were input for model verification. Observed and simulated time series of water level for the year 2000 flood at stations along the main channels as well as in the delta itself in Dong Thap Muoi and Long Xuyen quadrant show good agreement (Figure 6). Simulated results for maximum water levels are presented by contour map in Figure 7. Ob-served flood trace points obtained from Viet-

nam's National Center of Hydro-Meteorology dur-ing the flood season are shown in Figure 7. In addition, inflow and outflow from Dong Thap Muoi and Long Xuyen quadrant (Figure 1a) were also compared with the values measured during

the flood investigation in Figure 8. It is clear that a good agreement also exists between the pre-dicted values and observed values. This implies that the validated results can be used to analyze the inundation regime in this area.

In 2000, flood flow from Cambodia to Doug Thap Muoi was threefold larger than that to Long Xuyen quadrant (see Figure 8). The flood prop-

agated more to Doug Thap Muoi than to Long

Xuyen quadrant via the Cambodia-Vietnam

boundary. At the beginning of the flood season,

the deep inundation areas were located near the boundary, then expanded downstream farther

into the Vietnamese part of the Mekong River

Delta. The inundation area of the whole Dong

Thap and Long Xuyen quadrant corresponding to

the different depths are calculated in Table 3. It

can be seen that in August, the area inundated

to a depth greater than 1.5 m in Doug Thap Muoi was twice as large as the corresponding area in

Long Xuyen quadrant. This may be attributable

to the flood control embankments in An Giang

province (location shown in Figure la), which are designed to protect from early flood, and to

the canals for draining flood water to the Gulf of

Thailand.

Figure 9 shows the durations of flooding cor-

responding to each level of inundation depth in

different months. Flooding propagated to Dong

Thap Muoi and caused inundation from August.

The inundated area expanded widely in the

whole region; inundation depths began to exceed

2.5 m from the middle of September upstream of

Dong Thap Muoi, and even from the beginning

of September in some regions near the Hong Ngu

canal (Figure 6). The very high tides, with peaks

of 4.05-4.16 m at the end of September and be-

ginning of October, aggravated this severe inun-dation. The area inundated to this depth receded

in October. But in some regions, such as between

-671-

174 HOA L. T. V., HARUYAMA S ., NHAN N. H., LONG T. T., and LONG B. D.

Figure 6. Time series of observed and simulated water level at various locations in Vietnam Mekong River

Delta in 2000.

- 672-


Figure 7. Simulated maximum water level and observed flood trace points in 2000 for the region shown by

the box in Figure la.

Figure 8. Time series of observed and simulated discharge from Cambodia to Mekong River Delta in Viet-

nam.

-673-

176 HOA L. T. V., HARUYAMA S ., NHAN N. H., LONG T. T. , and LONG B. D.

Figure 9. Distribution of time period corresponding to the inundation depth at (a) 1.5 m in August; (b) 2.5 m in September; (c) 2.5 m in October and (d) 1.5 m in November in the region shown by the box in Figure la.

-674-


Figure 9. (c), (d).

-675-

178 HOA L . T. V., HARUYAMA S., NHAN N . H., LONG T. T., and LONG B . D.

Table 3. Inundation area in Dong Thap Muoi (DM) and Long Xuyen quadrant (LX) in 2000 (km2)

Figure 10. Paddy field considered in the study.

the canals Tan Thanh, Lo Gach, and Hong Ngu

(see locations in Figure 6), between two tribu-taries of the Mekong River, this deep inundation

persisted until the end of October. In November, when the inundation receded, the maximum inundation depth was about 2 m for a short pe-riod, but inundation to a depth of 1.5 m persisted over quite a large area.

The simulated results show that inundation levels were deeper in Dong Thap Muoi than in Long Xuyen quadrant (Figure 6), and inundation in the eastern and southern parts of Long Xuyen

quadrant seem to be shallower. This complication is attributable to many causes, including such

flood control measures taken as raising the ele-vation of the roads, building an embankment sys-tem, and improving the canal network, which contributed to making some separated hollows. The flood control embankments induced greater flood flow propagation to the northeastern region

and the westernmost region of the Mekong delta. The flood control measures contributed positive effects to inundation level reduction in such re-

gions as Kien Giang, Can Tho, and Tien Giang provinces (see locations in Figure la).

Inundation maps combined with rice crops of

the land use map in 2000, which consist of the

(Summer-Autumn) rice crop (Figure 10) show

-676-


Table 4. Percentage of inundated area by August flood with depth greater than 1m according to duration

(day)

(a) For double rice crop

(b) For single rice crop

(c) For triple rice crop

Table 5. Percentage of inundated area by August flood with depth greater than 1.5 m according to duration

(day)

(a) For double rice crop

(b) For single rice crop

(c) For triple rice crop

-677-

180 HOA L. T. V., HARUYAMA S., NHAN N . H., LONG T. T., and LONG B. D.

Figure 11. Total time duration of maximum inundation depth during flood season 2000 in the region shown

by the box in Figure 1a.

which (Summer-Autumn) paddy field areas were affected by the Autumn flood. Percentage of in-undated area by August flood over total area of each rice crop are shown in Tables 4 and 5. Dou-ble rice crop areas (Winter-Summer and Sum-mer-Autumn) mainly located in Dong Thap Muoi and Long Xuyen quadrant are affected strongly by August floods (Tables 4 and 5). Subjected to

inundation depths greater than 1 m in August flood, 57% of this area in Dong Thap, 19% of this area in Long An, and 44% of this area in An Giang were inundated to a depth of over 1 m for more than 25 days. This may be attributable to

early flood control measures designed to protect the crop.

The distribution map of the total time period

corresponding to the maximum inundation depth in Figure 11 shows that in Long Xuyen quadrant, despite existing flood control structures, the du-ration of inundation persistence was still long. The total duration of maximum inundation depth during the year 2000 flood season was about 4 months. The wide range of Dong Thap Muoi has long inundation periods of 140 days. This implies that flooding propagated to Dong Thap Muoi ear-lier.

Conclusion

The hydraulic model HydroGis is capable of

simulating flood in Mekong River Delta, and its

results, have acceptable accuracy to perform

detailed analyses of inundation regimes in this

region. The advantage of this model is that link-

ing with GIS is convenient to analyze the inun-

dation impact on paddy fields by using combina-

tions of land use maps and computed inundation

maps. In this study, we also set up a topograph-

ical and hydro-meteorological database for Hy-

droGis model's computation network that will be

a basis for further studies of floods and the ef-

fects of infrastructure changes on flood regime

in the Mekong River Delta. By using HydroGis

model with this database, detail maps of the in-

undation, duration in the flood region as well as

durations corresponding to each inundation

depths in 2000 for Dong Thap Muoi and Long

Xuyen quadrant, which suffer annual flooding,

were provided.

Analysis of flood records over the past 78

years indicates that the flood of 2000 was extremely large and has a occurrence frequency

-678-


of about 5% . Although the year 2000 flood lev-els did not exceed historically recorded levels upstream, they did exceed the historically recorded levels downstream. This discrepancy may be attributed to the combined impacts of the upstream flood, spring tide, rainfall and the flood control structures. The computed results

provide detailed information about inundation depths, durations in each region, and area inun-dated by the flood of 2000. In addition, the com-

bination of model results with land use maps show the effects of flooding on land use, espe-cially on Summer-Autumn crop in August flood in affected regions of Dong Thap and An Giang

provinces. Embankment elevation should be con-sidered in order to protect the Summer-Autumn

paddy crop from 5% probability flood occurrence in August. This study provides basic information to contribute to embankment elevation design and policy making toward flood mitigation and living with flood in the Mekong River Delta in

Vietnam.

(Received 18 May 2006) (Accepted 28 March 2007)

References

Correia, F. N., Rego, F. C., Saraiva, M. G., and Ramos, I. 1998. Coupling GIS with hydrologic and hy-draulic flood modeling. Water Resource Manage-ment 12: 209-227.

Dac, N. T. 1996. Software TLUC96 for flood computa-tion in Cuu Long river delta. In Proceedings of conference on food modeling in Cuu Long River Delta. Ho Chi Minh: Ministry of Water Re-source. (V)

DeVantier, B. A., and Feldman, A. D. 1993. Review of GIS applications in hydrologic modeling. J. Water Resour. Plan. Management, ASCE 119: 246-261.

Dong, T. D. 2000. VSAP model and its applications. In Proceedings of workshop on hydrologic and en-vironmental modelling in the Mekong Basin. ed. R. W. Al-Soufl, 236-245. Cambodia: Technical Support Division, Mekong River Commission. Phnom Penh.

Hagiwara, T., Kazama, S., and Sawamoto, M. 2002. Re-lationship between inundation area and irrigation area on flood control in the lower Mekong. In Pro-ceedings of the 13th IAHR-APD congress, Sin-

gapore 6-8 Aug. 2002. Singapore. Volume II, 590-595.

Huynh, L. B. 2002. Study and assessment of flood 2001

in Mekong River for completing flood forecast methods in Cuu Long River Delta. In Project of

flood investigation and assessment for 2001 in Cuu Long River Delta. Hydro-Meteorological Ser-vice of Vietnam. (V)

Jam, M. K., and Singh, V. P. 2005. DEM-based model-ling of surface runoff using diffusion wave equa-tion. Journal of Hydrology 302: 107-126.

Kazama, S. 2001. Report on flood and inundation in the Mekong River Basin in 2000. Journal of Japan Society for Natural Disaster Science 19: 493-500. (J)

Kazama, S., Muto, Y., Nakatsuji, K., and Inoue, K. 2002.

Study on the 2000 flood in the lower Mekong by field study and numerical simulation. In Proceed-

ings of the 13th IAHR-APD congress, Singapore 6-8 Aug. 200,2. Volume I, 534-539.

Kubo, S. 2006. Geomorphological features, flood char-acters, land-use and water-use in lower Mekong

plain in. Cambodia. Gakujutsu kenkyu school of education, Waseda University, Series of Edu-

cation 54: 1-9. (J) Lanh, D. T., and Minh, N. V. 2004. Improve KOD.01

with GIS application and information technology for flood calculation in Cuu Long river delta. In Scientific and technology collection. Southern Institute of Water Resource Science. ed. L. Sam et al. 401-413. Hanoi: Agriculture Publishing House.

Le, T. V. H., Haruyama, S., Nguyen, H.N., and Tran, T.C. 2005. Study of 2001 flood using numerical model in the Mekong River Delta, Vietnam. In Proceeding of international symposium on

floods in coastal cities under climate change conditions, ed. D. Dutta and M. S. Babel, 65-73. Thailand: AIT.

Le, T. V. H., Haruyama, S., Nguyen, H. N., and Tran, T.

C. 2006. Simulation and analysis of flood 2002 in Mekong River Delta. In Proceeding of interna-tional symposium on water and land manage-ment for sustainable irrigated agriculture, 8. Adana, Turkey. Cukurova University.

Umitsu, M., Nguyen, V. L., and Ta, T. K. 0. 2004. Geo-environment and flood 2000 in the Mekong River delta. Journal of the Faculty of Literature, Nagoya University. History 50: 57-69.

Mekong River Commission 2001. Strategic master scheme for hydro-meteorological network in the Mekong river basin. Phnom Penh Mekong River Commission.

Mekong River Commission 2004. Water utilization

program- start-up project: Overview of the hy-drology of the Mekong Basin. Phnom Penh Mekong River Commission.

Nguyen, H. N., and Tran, T. C. 2003. HydroGis Soft-

-679-

182 HOA L. T. V., HARUYAMA S., NHAN N. H., LONG T. T., and LONG B. D.

ware. In Proceeding of conference on develop-ment and application of new technology in the

period 1993-2003. 50-58. Hydro-Meteorological Service. (V)

Nguyen, H. N., Tran, T. C., and Ho, N.D. 2002. Hydr-oGis software: Technical instruction. Ho Chi

Minh: Water Resource University Publication. (V) Nien, N. A. 1996. KOD model for flood computation in

Cuu Long river delta. In Proceedings of confer-ence on flood modeling in Cuu Long River Delta. Ho Chi Minh: Ministry of Water Resource.

(V) Nien, N. A., Lanh, D. T., and Hanh, N. V. 2004. Intro-

duction of KOD.WP software for water resource and sedimentation computation. In Scientific and technology selections, southern institute of

water resource science. ed. L. Sam et al. 387-394. Hanoi: Agriculture Publishing House. (V)

Shahin, M., Van Oorschot, H. J. L., and De Lange, S. J. 1993. Applied hydrology monographs: Statistical analysis in water resources engineering. ed. A. A.

Balkema, Rotterdam: Brookfield. SOGREAH, 1963. Modele mathematique du delta du

Mekong. Vol IV-3. Exploitation du modele de-

finitive. Paris: UNDP-UNESCO. (F) Thuy, D. T., and Dac, N. T. 2000. Modelling of flow and

salinity in the Mekong Delta by SAL99 model. In Proceedings of workshop on hydrologic and en-vironmental modelling in the Mekong Basin. ed. R. W. Al-Soufi, 225-235. Phnom Penh: Tech-nical Sopport Division, Mekong River Commission.

Truong, T. V. 2006. Flood identification, forecast and control in Cuu Long river delta. Agriculture

publishing house. (V) Vieux, B. E. 1991. Geographic information systems and

non-point source water quality and quantity mod-eling. Hydrological Processes 5: 101-113.

(F): written in French (J): written in Japanese (V): written in Vietnamese

-680-

the historical flood in 2000 in mekong river delta

Documents