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Bac Lieu province, a low-lying coastal province in the Ca Mau peninsula of the Mekong River Delta (MRD) of Vietnam, is recognized as an area strongly affected by sea-level rise (SLR) accompanying global climate change. SLR will aggravate inundation and salinity intrusion and hence exert a strong influence on agriculture and aquaculture production in the province. The study presented in this chapter aims to quantify the impacts of SLR on agriculture in this province and to propose adaptive options. The 'Vietnam River Systems and Plains' (VRSAP) model was used for simulation of water level, flow and salinity in the canal network of the MRD for 3 years of low, average and high water volume from upstream of the MRD and different levels of SLR (12, 17, 30, 50 and 75 cm). Under present sea level conditions, the western part of the province faces the highest flooding risk in October during the rainy season. In the dry season, salinity is high in the western part where farmers grow brackish water shrimp, while it is low in the eastern part where rice is grown. The inundation depth increases with the level of the SLR. For SLR less than 30 cm, salinity is expected to decrease slightly due to more fresh water from the Bassac River. When SLR is higher than 30 cm, salinity in the eastern part will also increase because the saline water intrudes into freshwater intake canals along the Bassac River. In the near future, adjustment of the cropping calendar as well as the operations of existing water control structures will be required. In the distant future, additional structures will be needed to cope with aggravated inundation and salinity.

In Hoanh, Chu Thai; Johnston, Robyn; Smakhtin, Vladimir. Climate change and agricultural water management in developing countries. Wallingford, UK: CABI

In Hoanh, Chu Thai; Johnston, Robyn; Smakhtin, Vladimir. Climate change and agricultural water management in developing countries. Wallingford, UK: CABI

This research study uses a qualitative approach to examine the implementation of the ‘Five Million Hectare Reforestation Program’ (the 5MHRP) in Vietnam, and to explore the underlying reasons for local people’s participation in the program. The study also uses a transactional model to examine the private transaction costs borne by farmers when carrying out forest management activities under the program. The study reveals that: (i) the implementation of the program was generally characterized by a top-down process, (ii) the principal contribution to household benefits derived from forest management activities was the collection and sale of non-timber forest products, not the subsidy provided by the government, (iii) the main challenges faced during implementation of the program were the low and fixed subsidies provided, the improper types of trees being planted, poor access to the forest, and a lack of awareness among local people towards the benefits to be derived from participation in the forest management program, and that (iv) under the program’s community contracts, attending meetings (52%) and self-monitoring activities (35%) constituted the largest proportion of total time spent on forest management, while under the individual contracts, self-monitoring activities (98%) were the main component. Participating in the planting and protection of forests under the program brought greater benefits to households than when involved in forest protection activities alone. The main implications of this study are that an increase of payments under both types of contract, and especially the community contract, as well as the provision of higher quality seedlings and fertilizers, need to be taken into consideration in future initiatives. In addition, local communities and authorities should be further empowered, and their contribution should be taken into consideration in future programs.

In Hoanh, Chu Thai; Szuster, B. W.; Kam S. P.; Ismail, A. M; Noble, Andrew D. (Eds.). Tropical deltas and coastal zones: food production, communities and environment at the land-water interface. Wallingford, UK: CABI; Colombo, Sri Lanka: International Water Management Institute (IWMI); Penang, Malaysia: WorldFish Center; Los Banos, Philippines: International Rice Research Institute (IRRI); Bangkok, Thailand: FAO Regional Office for Asia and the Pacific; Colombo, Sri Lanka: CGIAR Challenge Program on Water and Food (CPWF).

This study assessed the variability of flows under present and 'naturalized' basin conditions in the Upper Ganges Basin (UGB). Furthermore, the PRECIS regional climate model (RCM) was used to generate climate projections for the UGB, with subsequent simulations of future river flows. Results show that the annual average precipitation, actual evapotranspiration (ET) and net water yields of the whole basin were 1,192 mm, 416 mm and 615 mm, respectively. Precipitation, ET and water yields were found to be higher in the forested and mountainous upper areas of the UGB. On an annual average, present-day flows throughout UGB are about 2-8% lower than under naturalized conditions. Dry and wet season flows under climate change (CC) scenario A2 are lower than that under present climate conditions at upstream locations, but higher at downstream locations of UGB. Flows under CC scenario B2 are systematically higher and lower than that under CC scenario A2 during dry and wet seasons, respectively.

The BayFish–Bac Lieu model presented in this chapter is a Bayesian model that aims to identify optimal water control regimes and trade-offs between water uses in order to improve management of water-dependent resources in the inland coastal area of Bac Lieu Province, Mekong Delta, Vietnam. The model was developed between 2004 and 2007 and integrated local databases, outputs from the Vietnam River Systems and Plains (VRSAP) model and stakeholder consultations. The model facilitates analyses of the consequences of different water management scenarios (quantitative and qualitative) on rice, fish, crab and shrimp production in the province. However, beyond production, trade-offs between household income, food security or environmental protection were also identified during the model development process. Subsequently, the BayFish–Bac Lieu model allows detailing of: (i) annual production probabilities in the case of a baseline scenario; (ii) outcomes of four different sluice gate operation modes; and (iii) trade-offs between household income, food security and environment outcomes for each scenario. The model shows that through improved shrimp farming and fish production, total household income benefits directly from open sluice gates allowing saline intrusion. However, this has the opposite effect on rice production, and on food security. Results suggest that a suitable compromise involving at least one sluice gate open at all times should be adopted for optimized outcomes., In Hoanh, Chu Thai; Szuster, B. W.; Kam, S. P.; Ismail, A. M; Noble, Andrew D. (Eds.). Tropical deltas and coastal zones: food production, communities and environment at the land-water interface. Wallingford, UK: CABI; Colombo, Sri Lanka: International Water Management Institute (IWMI); Penang, Malaysia: WorldFish Center; Los Banos, Philippines: International Rice Research Institute (IRRI); Bangkok, Thailand: FAO Regional Office for Asia and the Pacific; Colombo, Sri Lanka: CGIAR Challenge Program on Water and Food (CPWF).

International audience; Over recent years, the scientific community has developed different modelling methodologies of land use/cover change (LUCC) depending on their intended use, and also on the scale of investigation, disciplinary background and scientific tradition of the research teams. Consequently, each LUCC model has its own potential and constraints with respect to the needs and expectations of land use planners and policy makers. Faced with the issue of integrated management of natural resources from local to regional scales, agricultural research can benefit from reconciling top-down and bottom-up approaches to LUCC modelling.Three modelling methodologies belonging to these two LUCC approaches were applied in the province of Bac Kan in northern Vietnam. The multi-agent model SAMBA was developed through an adaptive, bottom-up process while LUPAS and CLUE contributed to a top-down process. Applying these three methodologies at the same research site allowed a critical evaluation of their respective utility for land use analysis and planning. They played complementary roles in bridging knowledge gaps and increasing interactions between stakeholders along the continuum from research to development and policy formulation. Combined use of these modelling methodologies should be promoted when complex natural resource management issues at multiple scales need to be tackled.

Station 1: Soil erosion and land management focused research; International audience; This poster studies the impact of land-use change on soil loss from sloping lands, presenting research on biophysical processes and their environmental and economic consequences. Farming systems are also analysed to infer the driving forces behind farmer strategies and practices. The Vietnam MSEC research program works in a small agricultural experimental watershed of around 50 ha, northeast of Hanoi. The cultivated steep slopes have been equipped to assess water discharge and sediment loads. Soil erosion here has negative impacts on upstream and downstream communi-ties. Increased sediment from these catchments reflects a loss of the fertile topsoil that farmers depend upon. In addition, increased sediment loads in streams and rivers have a negative impact on water quality and the longevity of water storage structures, both of which have significant economic and environmental implications.

In Hoanh, Chu Thai; Tuong, T. P.; Gowing, J. W.; Hardy, B. (Eds.). Environment and livelihoods in tropical coastal zones: managing agriculture, fishery, aquaculture conflicts. Wallingford, UK: CABI; Los Banos, Philippines: International Rice Research Institute (IRRI); Colombo, Sri Lanka: International Water Management Institute (IWMI).

In Hoanh, Chu Thai; Tuong, T. P.; Gowing, J. W.; Hardy, B. (Eds.). Environment and livelihoods in tropical coastal zones: managing agriculture, fishery, aquaculture conflicts. Wallingford, UK: CABI; Los Banos, Philippines: International Rice Research Institute (IRRI); Colombo, Sri Lanka: International Water Management Institute (IWMI).