Population Growth and Natural-Resources Pressures in the Mekong River Basin pdf

Sokhem Pech and Kengo SunadaPopulation Growth and Natural-Resources Pressures in the Mekong River Basin The Mekong River Basin possesses the region’s largest potential water source and r

Sokhem Pech and Kengo Sunada

Population Growth and Natural-Resources

Pressures in the Mekong River Basin

The Mekong River Basin possesses the region’s largest

potential water source and related resources, which

support ongoing economic development and basin

com-munity livelihoods It is currently witnessing a major

demographic transition that is creating both opportunities

and challenges An analysis of the complex relationship

between demographic changes and impacts on the

natural-resource base confirms that resource exploitation

is occurring not only to meet growing domestic needs but

also for other vested interests Population, together with

other major drivers, such as institutions, markets, and

technology, will have a very strong bearing on the way in

which the rich resources of the Mekong River Basin are

developed and distributed in the present and future The

Mekong River Basin’s rich resources, and the benefits

derived from them, are unevenly distributed both in time

and geographically Moreover, since the causes and

impacts do not respect political boundaries, the Mekong

countries need to jointly develop alternative management

strategies to meet projected demands within the

sustain-able capacity of the Mekong River Basin natural-resource

base

INTRODUCTION

The Mekong countries have a complex, but interesting, mosaic

of demographic attributes and trends The population of the

Mekong region—whole of Yunnan Province of China,

Myan-mar, Laos, Thailand, Cambodia, and Vietnam—is nearly 300

million, and over 70 million people live in the Mekong River

Basin (1) The Mekong Basin possesses the region’s largest

potential water source and related resources These resources

are fundamental to ongoing economic development in terms of

irrigation and agricultural production, fisheries and

aquacul-ture, energy and forest products, navigation and other modes of

transport, domestic and industrial water supply, and tourism

(2) Levels of dependency on the river’s water and related

resources are very high, particularly among the rural poor, who

rely on subsistence livelihoods and moral economy (3)

Recent socioeconomic development has begun to slow

population growth rates in China, Thailand, and Myanmar,

while Cambodia, Laos and Vietnam are expected to experience

further positive growth well beyond 2050 (4) It is also true that

the population growth rates vary considerably across the

Mekong River Basin, within and between the basin countries

(2) For example, Yunnan population density has doubled since

the 1950s, reaching the current level of 103 people km2, but in

the Lancang/Mekong part, the population density is only 62

people km2 due to the rugged and inhospitable landform (5)

On the other hand, Yunnan population growth rate has

declined slower than other parts of China (present level of

1.3% y1compared to less than 0.7% annually for all of China)

(5)

Accordingly, the overall Mekong populations are projected

to increase well beyond 2050 The population growth and

expected demographic changes in these countries create both

opportunities and challenges

Population size and its composition have significant impli-cations for pressures on natural resources Growing populations require more or different food, which typically requires land and water or other forms of production (6) This paper examines population growth and its likely impacts on food demand and land and water resources in the Mekong River Basin in a systematic and integrated manner As a first step, we present a clear overview of demographic trends in the Mekong River Basin Next, we conduct a comprehensive analysis to explore the complex relationship between demographic change and impacts on the natural-resource base in the Mekong River Basin

Purpose and Methodology The main purpose of this paper is to stimulate policy debate over the current national focus on food self-sufficiency and a broader national and regional development agenda in the Mekong River Basin We provide the context, empirical evidence, and an analysis of the demand (real or perceived) associated with population growth We also present a compar-ison of demand forecasts with the sustainable potential of the natural-resources base of the Mekong River Basin in order to contribute to a better understanding of this immense and complex Mekong River Basin environment

Population growth, food and water demands, and their impacts on water resources in both the Mekong River Basin and other river basins around the world have been discussed in a number of studies (e.g., 6–10) While the approaches used and information provided by these studies give a good indication of annual food and water demands, they generally do not provide information about water and other related resources necessary for meeting food demand at finer timescales, such as during critical dry-season months, or at more specific geographical scales

This paper reviews conditions and trends in the Mekong River Basin through both quantitative and qualitative analysis

It examines both underlying opportunities for and threats to sustainable water-resources management in the Mekong River Basin at critical time periods and at key locations along the Mekong main stem as shown in Figure 1 To this end, the study makes use of a systematic assessment framework that allows for identification of both key issues and appropriate management responses to balance environmental and socioeconomic devel-opment objectives The study tests the hypothesis of a complex multidimensional relationship among key demographic attri-butes and other intervening factors, such as institutions, policy, technology, culture, and the natural environment

DEMOGRAPHIC TRENDS IN THE MEKONG RIVER BASIN

Overcoming Different Population Growth Rates The Mekong River Basin population is over 70 million and is expected to increase rapidly (1) Projections of population growth in the Mekong River Basin differ widely as a result of both different methods of enumeration and poor reporting (1, 8, 10) To address this problem, this study derives the Mekong

River Basin population growth rate from the national

population growth rates of each country represented in the

Mekong River Basin adjusted to the specific conditions of the

Mekong River Basin United Nations (UN) data (4) on key

population statistics for China, Laos, Myanmar, Thailand,

Cambodia, and Vietnam were analyzed The rate of natural

increase was estimated for each country from 1970 to 2050 as

the birth rate less the death rate, assuming that the rate of net

migration is zero Population growth in the basin over a 50 y

period is projected based on two scenarios: scenario A—where

the natural population increase rate changes over time as

estimated above; and scenario B—where the rate of natural

increase is kept constant at year 2000 levels as estimated by the

Mekong River Commission (MRC) (1)

Discussion of Population Growth Outlook

The projections estimated by the present study show that the

Mekong River Basin population grew from 63 million in 1995

to over 72 million in 2005 This is in good agreement with the

observed/estimated data (1) Under scenario A, by 2050, the

Mekong River Basin population is expected to grow by another 60%, while under scenario B—constant growth—it will double its 2005 values Empirical evidence suggests that future population growth in the Mekong Basin is likely to follow the trends projected under scenario A (4)

While these figures are only indicative, they do point to the complexity associated with policy debate around population growth as metajustification for natural-resources exploitation in Mekong River Basin Most, if not all, Mekong countries have argued that to fulfill the resource requirements (perceived or real) of a growing population, some form of water and/or land-use change will be required to support increasing human numbers (1, 11, 12, 13)

FOOD DEMAND GROWTH PROJECTION IN THE MEKONG RIVER BASIN

Selecting a Method for Projecting Food Demand Total food demand projections usually depend on three crucial factors: i) population size; ii) increase in per capita consump-tion and life style; and iii) changes in the composiconsump-tion of diet (10) Data on the Mekong River Basin population size is available (as shown previously), and changes in per capita consumption can be estimated from Food and Agriculture Organization (FAO) food balance sheets (14) An analysis of the data on the composition of average daily diet (1990, 1995, and 2000) of all six Mekong countries shows that more than 65% of the daily calorie supply is provided by cereals (rice and wheat), both directly as cereal products and indirectly through animal products (14) It is therefore assumed in this study that such a change in lifestyle would be minimal over the next 40 y, and that cereal products and rice will remain the major staple foods in the Mekong River Basin in the coming decades Some early Mekong River Basin studies applied a method for calculating food demand that built on an assumption of per capita demand of 300 kg y1of paddy or equivalent across all Mekong countries (see, e.g., 9) An analysis of the FAO food balance sheets (14) (1990, 1995, and 2000) shows that method was overgeneralized because food composition and availability differ from country to country The food balance sheets also provide information about average per capita food supplies, which can be used to measure long-term trends in national food demand and diet composition In this study, domestic food demand is considered as the sum of a country’s demand for food and other uses from available supplies, such as seed use, livestock feed, food manufacturing, and farm and market waste (postharvesting, transport, and retail losses)

Discussing Food Demand Estimates Year 2000 cereal (rice, maize, and wheat) demand in the Mekong River Basin was estimated to be around 20.65 million

t Based on the constant population growth in scenario B, total cereal demand in the basin will more than double to around 44.1 million t by 2050 Under scenario A, cereal demand is projected to increase by nearly 60% (roughly 11 million t more than 2000 values), as shown in Figure 2

Comparing this demand with the 2000 paddy rice production

of 30.64 million t in the Lower Mekong Basin (15), and assuming no changes in paddy production levels or farming practices, the Mekong River Basin is likely to produce enough rice to feed its basin community until 2030 or 2040 (see Fig 3) Northeast Thailand and the Vietnamese Delta—major rice producers and exporters—are likely to produce rice surplus even after 2050 However, malnutrition remains in many of the least-developed parts of the basin—Myanmar, Laos, and Cambodia (2) This is mainly due to problems of distribution Figure 1 Mekong River key monitoring stations (27).

and nonaffordability by some low-income groups, rather than

of an absolute lack of food (1) As far as the expansion of food

production in the future is concerned, the Mekong countries

have different potentials and constraints These are discussed in

the next section

THE RELATIONSHIP BETWEEN POPULATION

GROWTH AND AGRICULTURAL LAND EXPANSION

IN MEKONG COUNTRIES

An analysis of long-term population (4) and cropping-area

changes in all countries in the Mekong region during the past

four decades (1960–2004) (16) does not produce a uniform

relationship between population growth and land-use change

All Mekong countries except for Myanmar experienced

cropping land area increases in proportion to the increase of

population until 1995, whereafter agricultural land expansion

has been much slower than population growth This result

suggests that although population size is an important

determinant of agricultural land-use change, its form and the

intensity of change in the Mekong River Basin in a particular

locale are influenced by other factors, including land-tenure

policies, international markets for forest and agricultural

products, land resource availability and the level of competition

for it, technological factors, and development impacts (16)

Food Demand Growth and Impacts on Land Use

Numerous studies have highlighted the major influence of land

and water productivity on overall food production (e.g 16, 17)

This study applies a Crop Area Production Model to evaluate

crop-area demands by taking into account not only food

demand and population change, but also land and water

productivity levels (16) For this study, the year 2000 yield was assumed to grow at the rate observed between 1987 and 1997 Figure 3 shows the increase in the crop-area demand in the whole Mekong River Basin projected by this study as compared against the 2000 observed paddy area data in the Mekong parts

of Yunnan, Laos, Thailand, Cambodia, and Vietnam (16, 17)

In a moderate scenario (A), the harvested area demand is likely

to increase to 9 million ha (i.e., an increase of 2 million ha from

2000 values) Similar trends are found at each individual Mekong River Basin country level If we compare crop production area demand with the 2000 paddy areas (roughly

7 424 000 ha or 11 597 000 ha, if double- and triple-cropping areas are counted), the projected paddy crop-area demand would exceed existing paddy crop areas by 2020 or 2045, respectively (16, 17) Given these findings, crop-area expansion appears to be inevitable in the Mekong River Basin This leads

to the question about whether there is any more room for this expansion This is discussed next

Any More Room for Agricultural Land Expansion in the Mekong River Basin?

At first glance, the future crop-area demand seems to be less than the land area available However, out of the Mekong River Basin total catchment area of over 795 000 km2 (795 million ha), only about 227.5 million ha is classified as Class A—land areas suitable for upland or irrigation agriculture (18) Furthermore, much less than half of this is available due to

Figure 2 Mekong Basin cereal demand projections comparing with

2000 cereal production (option A: population growth rate declining;

option B: population growth constant).

Is a human being an aquatic or terrestrial species? This question occasionally comes to the mind in the Mekong context Floating settlements on the shores of the Bassac River in Phnom Penh, Cambodia (Photo: O Varis).

Figure 3 Mekong River Basin growth in crop-area demand vs 2000

harvested crop area (option A: population growth rate declining;

option B: population growth constant) (land-use data source: 16).

high levels of degradation, remoteness, poor soil quality,

land-tenure issues, lack of access to water, and competition with

forestry, human settlements, industrial uses, and infrastructure

development, as shown in Table 1 (16, 19)

Vietnam and Thailand use their arable land in the Mekong

River Basin almost to its full extent for producing paddy rice

and other crops for both domestic consumption and export (16,

17) To meet growing needs beyond 2015, Cambodia and Laos

will have to increase the paddy production or develop an

alternative food-security strategy with clear actions and

appropriate mechanisms for implementing it While these

countries still have potential for paddy area expansion, they

need substantial investment in irrigation systems, transport

infrastructure, and market access (15)

ASSESSMENT OF POPULATION GROWTH AND

WATER AVAILABILITY ISSUES

Long-Term Per Capita Water Availability Trends in the

Mekong River Basin

According to the World Resource Institute, a basin reaches

‘‘water stress’’ when per capita water supply is less than 1700 m3

y1 (20) Compared to other river basins across the world in

term of actual renewable water resources per capita, the

Mekong Basin is not yet considered to be water-stressed An

average Mekong river flow of 474 932 MCM each year

theoretically can service the irrigation requirements of all

Mekong Basin countries many times (17) However, the region

still faces a series of water issues, including floods and drought

in many parts of the basin at different times of the year,

degradation of many key fish species and other important

habitats, and intensification of sectoral competition within and

among the Mekong countries (2) These water issues are closely

related to the unequal geographical and temporal distribution

of flow Furthermore, these issues are likely to intensify further

as a result of future population increases, changes in flow regimes due to built structures and irrigation diversions, and climate-induced change

Assessing Hydrological Impacts Due to Irrigation

It is understood that a series of large-scale economic activities in the Mekong subregion are at various stages of planning and development (3, 13, 21) The main source of major future impacts, both positive and negative, on the communities and natural resources of the Mekong River Basin is the development and operation of major hydropower schemes, other large infrastructure projects, and increased irrigation water diversion

in different parts of the basin (22)

Water abstraction from the Mekong is limited during the wet season when flow levels are high and rainwater is available However, there are many constraints on water utilization during the dry season, especially in drought years (23, 24) The dry seasons pose the most water challenges Therefore, we studied the changes to the minimum daily flows due to the expansion of irrigated paddy areas to the maximum potential of arable land

in the Lower Mekong Basin parts of Laos, Thailand, Cambodia, and Vietnam (15)

In examining the hydrological impacts of irrigation, for the purposes of this study, crop types were assumed to remain the same, and therefore existing proportions between different crop types within an irrigation area were retained The scenario limited the analysis to those crops associated with an increase in total water demand as a result of additional dry-season irrigation areas The paddy area of 2000 (in thousands of ha) and percentage assumed increase, crop irrigation lifetime and cropping calendar, the crop water unit requirement of irrigation water per hectare, and the return flow fraction are presented in Tables 2 and 3

We estimated the flow changes at Pakse and the Cambodia-Vietnam border (see Fig 1 for locations) and compared the

Basin area

Areas for upland agriculture

Area used (%)

Area suitable for irrigation (ha)

Area used (%)

Irrigation

poor access to market and high loss; landmine and small landholding; and low irrigation efficiency.

cost and low return; and low irrigation efficiency.

Vietnam Delta 10 100 68 3 256 200 88* 60% Water shortage, salinity, acid sulfate soil;

low irrigation efficiency; and high postharvest losses.

Thai NE 3 600 500 75 12 156 600 95 12% High labor cost; low-quality soil; salinity;

and low irrigation efficiency.

and irrigation potential is marginal; 41.8 is high slope greater than 258; and high erosion.

* Around 300 000 ha grow three crops of rice each year; 1 080 000 ha are double cropped (source: 16)   Pasture land z Farmland: 93% for single-rice cropping and 3% for double-rice cropping.

Table 2 Paddy area of 2000 and percentage of assumed increase (in thousands of ha), crop irrigation lifetime, and cropping calendar.

Basin country

Dry season, 3.5 mo, Feb–May Recession, 4 mo, Jan–Apr Spring/summer, 4 mo, Apr–Jul Winter/spring, 4 mo, Dec–Mar

(Data source: 16)

impacts of irrigation expansion on the Mekong Delta at low

flow to 1996–2000 average monthly flow volumes at Pakse and

Cambodia-Vietnam border, as estimated by the World Bank

(23)

Above Kratie, the total dry-season irrigation withdrawal is

projected to remain lower (in term of percentage) than the areas

below Kratie and in Vietnam’s Mekong Delta The 2000

estimated irrigation water demand in the Mekong River Basin

parts of Thailand and Laos was only 30% of the total average

flow volume at Pakse However, with an increase in irrigated

areas to 250% and 10% in Laos and Thailand, respectively, the

total irrigation demand would be close to 80% of total average

flow volume during the critical months of February and March

The dry-season flow change would be even more remarkable

with the projected increase of the dry-season irrigation in the

area further downstream of Kratie (Fig 1) It will further

exacerbate an issue of competing demands from other uses,

including in-stream environmental uses and critical habitat

maintenance for endangered species, which are known to

require water of a certain depth

The comparison of the irrigation volumes of 2000 with

average flow volumes in April and May shows that the

irrigation demand constituted 76%–81% of the flow availability

The results of irrigation volume estimates for downstream of

Kratie and in the Mekong Delta during the dry-season period

from December to July show an increase of 47% from the 2000

value of 32 096 MCM The average value and the actual flow

volumes may be higher or lower, since the baseline standard

deviation of wet and dry years is estimated to be around 23% on

average (24) This incident of dry-season shortage is confirmed

by the report of severe incidence of seawater intrusion in the

Mekong Delta area of Vietnam in very dry years With a

projected growth in irrigation water use, the critical dry-season

months—April and May—will face more serious water

short-ages and more competition among water users, as irrigation

demand alone will surpass flow availability (21)

DISCUSSION AND CONCLUSION

Population, together with other major drivers, such as

institutions and organizations, markets, and technology, will

have a very strong bearing on the way in which the rich resources of the Mekong River Basin are developed and distributed, both at present and in the future Levels of dependency of people on the river’s water and related resources are very high, particularly among the rural poor, who depend heavily on subsistence livelihoods However, the rich resources and the benefits derived from them are unevenly distributed both in time and space (3) They are exploited not only for meeting growing domestic needs but also for export demands, further demonstrating the high level of dependency on the rich natural resources of the Mekong River Basin as a source of economic growth The Mekong leaders maintain that the requirements of a growing population ultimately require some form of land-use change to provide for the expansion of food production, or to develop the infrastructure necessary to support increasing human numbers (1, 13, 14)

At first glance, the projected crop-area demands appear to be lower than the land available in the basin However, in reality, much less than half of this land is available due to high levels of degradation, remoteness, poor soil quality, land-tenure issues, lack of access to water and markets, and competition with other land-use activities, e.g., forestry, human settlement, industry, and infrastructures Some cash-trapped riparian countries need

to carefully assess land suitability, address irrigation viability (cost, access, and effectiveness), and market prices and access Furthermore, for these countries, securing and allocating substantial investment in irrigation systems, transport infra-structure, and market access is often very challenging

Water abstraction from the Mekong River Basin is limited during the wet season when flow levels are high and rainwater is available; however, there are many constraints on water utilization during the dry season, especially in drier years It is true that good water-resource management practices can increase the availability of water during critical periods, and that integrated planning that optimizes the benefits derived from waters can clearly increase the overall productivity of a river system Major (joint or several) development, such as the construction of dams and major abstractions for irrigation, presents special challenges due to the need to assess options and trade-offs and to apply environmental and social safeguards effectively and equitably across international borders and jurisdictions

The results of this study suggest that, in order to satisfy the requirement for further irrigation expansion in the Lower Mekong Basin and to prevent seawater intrusion into the Mekong Delta, a dry-season flow needs to be generated during the critical dry months, either from the points above Kratie or from Tonle Sap Great Lake (25, 26) Modeling results generated

by the MRC (2004) show that the development of Chinese dams (two existing dams and two larger planned dams) and six dams

on Laotian tributaries will have the effect of reducing flows beyond even the standard deviation of wet and dry years (estimated to be around 23%) at Kratie (which is used as a control point to monitor flow patterns and flow distribution in

Table 3 Estimated crop irrigated-water requirement and return

flow fraction.

Activity

Noncritical period,

May–Jan (m 3 ha 1 mo 1 )

Crop irrigation life (mo)

Critical period, Feb–Apr (m 3 ha 1 )

Return fraction

(Source: adapted from 16)

Figure 4 Total irrigation demand and average monthly flow volume

at Pakse and Cambodia-Vietnam border.

Cambodia’s floodplains and in Vietnam’s Mekong Delta) (23).

The generation of additional flow with major structural

measures in the Lower Mekong Basin floodplains is technically,

financially, and even ecologically challenging (27)

The issues described here are compounded by many factors,

such as:

– Each Mekong country tends to take an independent course

of action, often ignoring external and indirect effects This

represents one of the largest challenges to overcome, since

the asymmetry of causal responsibility, power/capacity, and

distributional problems are highly prevalent in the

subre-gion

– An effective and truly Mekong-wide institution for

negoti-ating cooperative development is lacking, and there is no

commonly accepted knowledge base or tools for impact

assessment and monitoring

– There is a lack of reliable data and knowledge, which leads to

a failure to fully understand and correctly evaluate impacts

and identify the causal mechanisms at work in large,

dynamic systems, and to consider and integrate multiple

risks and vulnerabilities

– Inadequate attention is given to the cumulative impact of

activities As the number of development projects in an area

increases, the incidence and importance of cumulative

impacts also increase Better approaches, guidelines, and

conventions for carrying out cumulative and cross-sectoral

impact assessment and monitoring are needed

In summary, growing food demand requires one or more of

i)further expansion of crop and irrigation areas; ii) increasing

crop and land-use intensities, diversity, and productivity levels;

iii) demand-side management, iv) a limit on irrigation

abstractions, significant improvements in irrigation efficiency

(i.e., adoption of a ‘‘more crop per drop’’ approach), or

diversification of crop types toward those requiring less water;

and v) virtual water trade

Vietnam presents an interesting case Statistically, it has

lowest ratio of water availability per person, but it has been

successful in increasing food production for domestic

consump-tion through high crop productivity and water- and land-use

intensity

References and Notes

1 Mekong River Commission (MRC) 2006 The MRC Basin Development Plan:

Completion Report for Phase 1 Mekong River Commission Secretariat, Vientiane,

Laos PDR, 104 pp.

2 MRC 2003 State of the Basin Report Mekong River Commission Secretariat, Phnom

Penh 316 pp.

3 Sokhem, P and Kengo, S 2006 The governance of the Tonle Sap Lake, Cambodia:

integration of local, national and international levels Int J Wat Res Dev 22, 299–416.

4 United Nations 2005 World Population Prospects: The 2004 Revision Population

Division of the Department of Economic and Social Affairs of the United Nations

Secretariat, United Nations, New York, dataset on CD-ROM.

5 Esa Puustjarvi 1999 Review of Policies and Institutions Related to Management of Upper

Watershed Catchments Report of Greater Mekong Subregion Watershed Project (Phase

II): Poverty Reduction and Environmental Management in Remote Greater Mekong

Sub-region Yunnan, China, 28 pp.

6 Boberg, J 2005 Liquid Assets: How Demographic Changes and Water Management

Policies Affect Freshwater Resources RAND Corporation, Santa Monica, CA, 107 pp.

7 Molden, D., Amarasinghe, U and Hussain, I 2001 Water for Rural Development.

Background paper on water for rural development Working Paper 32 International

Water Management Institute, Colombo, 91 pp.

8 Rosegrant, M.W., Cai, X and Cline, S 2002 World Water and Food to 2025: Dealing

with Scarcity International Food Policy Research Institute, Colombo, and International

Water Management Institute, Sri Lanka (http://www.ifpri.org/srstaff/rosegrantm.asp)

9 Hoanh, C.T., Guttman, H., Droogers, P and Aerts, J 2003 Water, Climate, Food, and

Environment in the Mekong Basin in Southeast Asia Final Report ADAPT Project.

Adaptation Strategies to Changing Environment, Amsterdam, 52 pp.

Agriculture in Priority River Basins, Section 4 World Wide Fund for Nature Publication, Living Water Programme, Netherlands, 32 pp.

11 Asian Development Bank (ADB) 2002 Key Indicators 2002: Population and Human Resources Trends and Challenges ADB, Manila (http://www.adb.org)

12 GMS Summit Declaration 2005 A Stronger GMS Partnership for Common Prosperity 2nd Greater Mekong Sub-region Summit, Kunming, Yunnan, China, 4–5 July 2005 ADB, Manila, 5 pp.

13 World Bank and ADB 2006 Future Directions for Water Resources Management in the Mekong River Basin Joint Working Paper World Bank and the Asian Development Bank, Vientiane, Lao PDR, 65 pp.

14 FAO 2005 AQUASTAT Information System on Water and Agriculture Online database Food and Agriculture Organization of the United Nations (FAO), Land and Water Development Division, Rome (http://www.fao.org/waicent/faoinfo/agricult/agl/ aglw/aquastat/dbase/index.stm)

15 Papademetrieu, M.K (ed) 2000 Bridging the Rice Yield Gap in the Asia-Pacific Region FAO RAP Publication, 219 pp.

16 BDP 2002 Basin Development Planning Regional Sector Overview: Agriculture and Irrigation Report MRC Secretariat, Basin Development Plan Programme, Phnom Penh, Cambodia, 32 pp.

17 BDP 2003 Water Used for Agriculture in Lower Mekong Basin Mekong River Commission Secretariat, Basin Development Plan Programme, Phnom Penh, Cambo-dia, 56 pp.

18 Molden, D., et al 2007 Pathways for increasing agricultural water productivity In: Water for Food, Water for Life Molden, D (ed) Earthscan, London, and International Water Management Institute, Colombo, 280 pp.

19 UNEP/GIWA 2006 Global International Waters Assessment: Mekong River GIWA Regional Assessment 55 University of Kalmar for United Nations Environment Programme, Bangkok, 75 pp.

20 Ravenga, C 2000 Will There Be Enough Water? World Resources Institute (http:// www.earthtrends.wri.org)

21 Ratner, B.D 2003 The politics of regional governance in the Mekong River Basin Glob Change 15, 59–76.

22 Lazarus, K 2003 Lancang-Mekong: A River of Controversy Mekong Watch, Southeast Asia Rivers Network (SEARIN), and International Rivers Network (IRN), Chiang Mai, Thailand, 75 pp.

23 World Bank 2004 Mekong Regional Water Resources Assistance Strategy: Modelled Observations on Development Scenarios in the Lower Mekong Basin World Bank, Vientiane, Lao PDR, 126 pp.

24 Halcrow Group Ltd 2004 Development of Basin Modelling Package and Knowledge Base (WUP-A) DSF 650 Technical Reference Report Appendix A 1–6 Halcrow Group Limited, for Mekong River Commission Secretariat, Phnom Penh, Cambodia, 260 pp.

25 SMEC 1998 Water Utilization Programme Preparation Project Final Report, SMEC/ MRC Secretariat, Bangkok, Thailand, 194 pp.

26 Daming, H 1997 Sustainable development of Lancang-Mekong River Basin and integrated multi-objective utilization research of water resources J Chin Geogr 7, 9–21.

27 Sarkkula, J and Koponen, J 2003 Modelling Tonle Sap for Environmental Impact Assessment and Management Support Final Report Finnish Environmental Institute and EIA Ltd., Helsinki, 110 pp.

Sokhem Pech is a senior international river basin governance specialist, Hatfield Group, Vancouver, Canada He has broad and multidisciplinary experience in water law; water and natural-resources management; institutional and organization development with specific focus on the Mekong subregion; regional policy formulation and hydrodiplomacy; multistake-holder dialogue and consultation; water-resources strategic assessment; water dispute management; and development of intercountry data- and information-sharing mechanisms His address: Natural Resources & Policy Researcher, 46DE0, 118 Street, Tuk La Ak I, Toul Kork District, Phnom Penh, Cambodia.

E-mail: speech@hatfieldgroup.com.

Kengo Sunada is a professor at the Department of Civil and Environmental Engineering, Interdisciplinary Graduate School

of Medicine and Engineering He is currently a leader of the Japan Science and Technology Agency’s research project

‘‘Sustainable Water Policy Scenario for River Basins with Rapidly Increasing Populations’’ and is developing counter-measure strategies to global hydrological variations in mon-soon Asia His address: Civil and Environmental Engineering Department, University of Yamanashi, Takeda 4-3-11, Kofu, Yamanashi 400-8511, Japan.

E-mail: sunda@yamanashi.ac.jp