Your search found 13 records
1 Hoanh, Chu Thai; Tuong, T. P.; Gallop, K. M.; Gowing, J. W.; Kam, S. P.; Khiem, N. T.; Phong, N. D.. 2003. Livelihood impacts of water policy changes: Evidence from a coastal area of the Mekong River Delta. Water Policy, 5(5/6):475-488.
Water policy ; Water quality ; Salinity control ; Rice ; Fish farming ; Living conditions ; Participatory rural appraisal ; River basins / Vietnam / Mekong River Delta / Ca Mau Peninsula
(Location: IWMI-HQ Call no: IWMI 333.91 G8784 HOA, PER, P 6702 Record No: H032176)
The coastal zone of the Mekong River delta has experienced rapid economic and environmental change during the last decade. Given the nature of the environment and the level of dependence on the natural resource base, policies for land and water were very influential in this process. The emphasis on rice created an imperative to control saline intrusion, which was realized through construction of major engineering works over an extended period (1994-2000). The inertia built up by this process led to a divergence between policy and practice, and adversely affected the livelihoods of fishers and of those farmers who live on aquaculture. This prompted the government to re-think about the rice-focus policy, in favor of a land and water policy for balanced rice and aquaculture production. The paper describes an analytical process, which was adopted to explore the feasibility of adopting the new policy for balanced development of both rice and shrimp production and discusses the impact of the new policy on farmers’ livelihoods.
2 Hoanh, Chu Thai; Phong, N. D.; Gowing, J. W.; Tuong, T. P.; Ngoc, N. V.; Hien, N. X. 2005. Hydraulic and water quality modeling: a tool for managing land use conflicts in inland coastal zones. Draft of paper presented at the International Conference on Environment and Livelihoods in Coastal Zones: Managing Agriculture-Fishery-Aquaculture Conflicts, Bac Lieu, Vietnam, 1-3 March 2005. 19p. [doi: https://doi.org/10.2166/wp.2009.107]
Water management ; Water quality ; Hydraulics ; Salinity ; Models ; Coastal plains ; Salt water intrusion ; Land use ; Conflict ; Case studies / Vietnam / Mekong Delta / Quan Lo Phung Hiep Region / Bac Lieu Province
(Location: IWMI-HQ Call no: IWMI 333.91 G784 HOA Record No: H038163)
3 Fanslow, G.; Tuong, T. P.; Hoanh, Chu Thai; Phong, N. D.; An, L. T.; Hien, N. X. 2005. Land-use and salinity management effects on water quality in Ca Mau Peninsula, Vietnam. Paper presented at the International Conference on Environment and Livelihoods in Coastal Zones: Managing Agriculture-Fishery-Aquaculture Conflicts, Bac Lieu, Vietnam, 1-3 March 2005. Draft – not to be cited. 31p.
Land use ; Salinity control ; Water quality ; Models / Vietnam / Ca Mau Peninsula / Mekong River Delta
(Location: IWMI-HQ Call no: IWMI 333.91 G784 FAN Record No: H038166)
4 Hoanh, Chu Thai; Phong, N. D.; Gowing, J. W.; Tuong, T. P.; Hien, N. X.; Dat, N. D. 2006. Predicting impacts of water management in coastal zones by hydraulic and salinity modeling. In Voinov, A.; Jakeman, A.; Rizzoli, A. (Eds). Proceedings of the iEMSs Third Biennial Meeting: "Summit on Environmental Modelling and Software." International Environmental Modelling and Software Society, Burlington, USA, July 2006. 6p.
Water management ; Coastal area ; Land use ; Conflict ; Water quality ; Salt water intrusion ; Simulation models / Vietnam / Ca Mau Peninsula / Mekong Delta
(Location: IWMI-HQ Call no: IWMI 333.91 G784 HOA Record No: H039625)
5 Phong, N. D.; Hoanh, Chu Thai; Tuong, T. P.; Malano, H.; Weaver, T. 2007. Modelling acidity propagation in a coastal zone with acid sulphate soils. In International Congress on Modelling and Simulation: Land, Water and Environmental Management: Integrated Systems for Sustainability. Organized by Modelling and Simulation Society of Australia and New Zealand, held at Christchurch, New Zealand, 10-13 December 2007. pp.170-176.
Water quality ; Water pollution ; Runoff ; Salinity ; Coastal area ; Simulation models ; Calibration ; Soil properties ; Salt water intrusion ; Irrigation canals ; Monitoring / Vietnam / Mekong Delta / Camau Peninsula
(Location: IWMI HQ Call no: IWMI 333.91 G784 PHO Record No: H040769)
6 Hoanh, Chu Thai; Phong, N. D.; Gowing, J. W.; Tuong, T. P.; Ngoc, N. V.; Hien, N. X. 2009. Hydraulic and water quality modeling: a tool for managing land use conflicts in inland coastal zones. Water Policy, 11(Supplement 1):106-120. [doi: http://dx.doi.org/10.2166/wp.2009.107]
Water quality ; Salt water intrusion ; Models ; Canals ; Land use ; Water management ; Rivers ; Investment planning ; Case studies ; Conflict ; Rice ; Aquaculture ; Brackish water / Vietnam / Mekong Delta / Ca Mau peninsula / Quan Lo Phung Hiep region / MyThanh River / Ganh Hao River / Cai Lon River / Ong Doc River
(Location: IWMI HQ Call no: e-copy only Record No: H042169)
Tidal effect and salinity intrusion are two defining characteristics of inland coastal zones, causing, respectively, complex variations in water levels and flows in river and canal networks, and serious problems for agriculture and freshwater fishery, but bringing significant benefits for brackish water aquaculture. To evaluate these conflicts and synergies in the development of agriculture, fishery and aquaculture, this paper adopts a hydraulic and salinity modeling approach that simulates the tidal propagation and salinity intrusion, and evaluates the effects of water and land use management on these hydrology- and salinity-related phenomena in coastal zones. The paper presents the empirical results from the application of a hydraulic and salinity model specifically developed for the context of the Ca Mau peninsula, Mekong Delta, Vietnam, and also demonstrates how such a modeling approach can provide valuable policy-relevant information at different phases for water resource planning, development, operation, and management in hydrologically and environmentally sensitive coastal regions.
7 Phong, N. D.; Hoanh, Chu Thai; Tuong, T. P.; Malano, H. 2010. Managing acidity movement in the coastal land with acid sulphate soils: a modeling approach. In Proceedings of the 19th World Congress of Soil Science, Soil Solutions for a Changing World, Brisbane, Australia, 1-6 August 2010. Wageningen, Netherlands: International Union of Soil Sciences (IUSS) pp.76-79 (Published on DVD)
Acid sulphate soils ; Simulation models ; Acidity ; Control methods ; Salinity ; Canals ; Coastal area / Vietnam / Mekong Delta / Camau Peninsula
(Location: IWMI HQ Call no: e-copy only Record No: H043265)
(0.20 MB) (202.81 KB)
A new acidity module has been developed and coupled successfully into an existing hydraulic and salinity model for simulating acidity movement in canals under the controlled marine water intake in the coastal land with acid sulphate soil (ASS). The model allied with the Camau peninsula, Mekong Delta, Vietnam indicates that the most suitable option for improving the acidity condition is to open main sluice gates one day every week when difference of tide amplitude of between the East and West seas is highest and to widen the canals connected to the West sea.
8 Hoanh, Chu Thai; Phong, N. D.; Trung, N. H.; Dung, L. C.; Hien, N. X.; Ngoc, N. V.; Tuong, T. P. 2012. Modelling to support land and water management: experiences from the Mekong River Delta, Vietnam. Water International, 37(4):408-426. (Special issue on "How hydrological models support informed decision making in developing countries" with contributions by IWMI authors). [doi: https://doi.org/10.1080/02508060.2012.706797]
Water management ; Water use ; Land management ; Land use ; Rivers ; Deltas ; Simulation models ; Optimization ; Policy making ; Hydrodynamics ; Water quality ; Canals ; Flood control ; Salinity control ; Aquaculture / Vietnam / Mekong River Delta
(Location: IWMI HQ Call no: PER Record No: H045027)
(3.15 MB)
By comparing the successful story of a hydrodynamic model (based on its contribution to policy changes, management options and livelihood improvement) with other modelling cases in the Mekong River Delta, five success factors are identified. These are (1) simulated phenomena relevant to and understandable by policy makers; (2) response to the needs of policy setting; (3) developed and handled by national modellers with direct links to the policy process; (4) availability of input data; and (5) long application history. These success factors provide higher opportunities for engaging modelling activities with policy setting.
9 Phong, N. D.; Tuong, T. P.; Phu, N. D.; Nang, N. D.; Hoanh, Chu Thai. 2013. Quantifying source and dynamics of acidic pollution in a coastal acid sulphate soil area. Water, Air, and Soil Pollution, 224(11):18p. [doi: https://doi.org/10.1007/s11270-013-1765-0]
Environment ; Pollution ; Water management ; Water quality ; Flow discharge ; Acidity ; Acid sulphate soils ; Soil properties ; Statistical analysis ; Canals / Vietnam / Bac Lieu Province
(Location: IWMI HQ Call no: e-copy only Record No: H046206)
(0.96 MB)
The in-depth knowledge on management and reducing annual acidic pollution is important for improving the sustainable livelihood of people living in areas with acid sulphate soils (ASS). This study involved a long-term (2001–2006), large-scale canal water quality monitoring network (87 locations) and a field experiment at nine sites to quantify the dynamic variability of acidic pollution and its source in a coastal area with ASS in the Mekong River Delta of Vietnam. Widespread acidic pollution (pH <5) of surface water occurred at the beginning of the rainy season, while pH of the canal water remained high (7–8) at the end of the rainy season and during the dry season. The study identified canal embankment deposits, made of ASS spoils from canal dredging/excavation, as the main source of acidic pollution in the surrounding canal network. The findings suggested that there was a linkage between the amount of acidic loads into canal networks and the age of the embankment deposits. The most acute pollution (pH ~ 3) occurred in canals with sluggish tidal water flow, at 1–2 years after the deposition of excavated spoils onto the embankments in ASS. The amount of acidic loads transferred to the canal networks could be quantified from environmental parameters, including cumulative rainfall, soil type and age of embankment deposits. The study implied that dredging/excavation of canals in ASS areas must be carried out judiciously as these activities may increase the source of acidic pollution to the surrounding water bodies.
10 Phong, N. D.; Hoanh, Chu Thai; Tuong, T. P.; Malano, H. 2014. Effective management for acidic pollution in the canal network of the Mekong Delta of Vietnam: a modeling approach. Journal of Environmental Management, 140:14-25. [doi: https://doi.org/10.1016/j.jenvman.2013.11.049]
Acidity ; Water pollution ; Deltas ; Salinity ; Canals ; Water management ; Water quality ; Models ; Coastal area ; Tides ; Shrimp culture / Vietnam / Mekong Delta
(Location: IWMI HQ Call no: e-copy only Record No: H046405)
(4.06 MB)
Acidic pollution can cause severe environmental consequences annually in coastal areas overlain with acid sulfate soils (ASS). A water quality model was used as an analytical tool for exploring the effects of water management options and other interventions on acidic pollution and salinity in Bac Lieu, a coastal province of the Mekong Delta. Fifty eight percent of the provincial area is covered by ASS, and more than three-fourths (approximately 175,000 ha) are used for brackish-water shrimp culture. Simulations of acid water propagation in the canal network indicate that the combination of opening the two main sluices along the East Sea of the study area at high tide for one day every week in May and June and widening the canals that connect these sluices to the West Sea allows for adequate saline water intake and minimizes the acidic pollution in the study area. On the other hand, canal dredging in the freshwater ASS area should be done properly as it can create severe acidic pollution.
11 Phong, N. D.; Hoanh, Chu Thai; Tuong, T. P.; Wassmann, R. 2014. Sea level rise effects on acidic pollution in a coastal acid sulphate soil area. In Ames, D.P., Quinn, N.W.T., Rizzoli, A.E. (Eds.). Proceedings of the 7th International Congress on Environmental Modelling and Software, San Diego, California, USA, 15-19 June 2014. Manno, Switzerland: International Environmental Modelling and Software Society (iEMSs) 8p.
Sea level ; Salinity ; Acidity ; Water pollution ; Coastal area ; Acid sulphate soils ; Deltas ; Canals ; Models / Vietnam / Mekong River Delta / Bac Lieu Province
(Location: IWMI HQ Call no: e-copy only Record No: H046614)
http://www.iemss.org/sites/iemss2014/papers/iemss2014_submission_223.pdf
https://vlibrary.iwmi.org/pdf/H046614.pdf
https://vlibrary.iwmi.org/pdf/H046614.pdf
(0.39 MB) (397.30 KB)
Bac Lieu is a coastal province the Mekong River Delta (MRD), Vietnam. Aside from salinity intrusion from the sea, the province is strongly affected by acidic pollution as 58% of the area (250,000 ha) is overlaid with acid sulphate soil (ASS). Previous studies showed that the eminent sea level rise (SLR) would influence the hydrology and salinity of the canal networks in the province. This study, using the previously validated hydraulic and water quality model VRSAP-ACIDITY (Vietnam River Systems And Plains, coupled with ACIDITY Module), aimed at quantifying impacts of different SLR scenarios (SLR = 17, 30, 50, or 75 cm) on acidic pollution in the province. Under the present sea level, widespread acidic pollution (pH < 5) of surface water occurred at the start of the rainy season, due to leaching of acidity from canal embankments and fields in ASS. The acceleration of SLR reduced the area of acidic polluted water. The lessening in acidic pollution was attributed to (1) SLR that raised the water level in the Mekong River, increasing the amount of fresh water flowing into the study area; and (2) the amount of water drained out of the study area increased, bringing with its acidity. It concluded that SLR has a positive effect on acidic pollution in the ASS coastal area.
12 Phong, N. D.; Hoanh, Chu Thai; Tho, T. Q.; van Ngoc, N.; Dong, T. D.; Tuong, T. P.; Khoi, N. H.; Hien, N. X.; Nam, N. T. 2015. Water management for agricultural production in a coastal province of the Mekong River Delta under sea-level rise. In Hoanh, Chu Thai; Johnston, Robyn; Smakhtin, Vladimir. Climate change and agricultural water management in developing countries. Wallingford, UK: CABI. pp.120-134. (CABI Climate Change Series 8)
Water management ; Agricultural production ; Coastal area ; Deltas ; Salinity ; Sea level ; Salt water intrusion ; Climate change ; Water levels ; Flow discharge ; Aquaculture ; Agriculture ; Flooding / Vietnam / Bac Lieu Province / Mekong River Delta
(Location: IWMI HQ Call no: IWMI Record No: H047375)
(2.46 MB)
13 Wassmann, R.; Phong, N. D.; Tho, T. Q; Hoanh, C. H.; Khoi, N. H.; Hien, N. X.; Vo, T. B. T.; Tuong, T. P. 2019. High-resolution mapping of flood and salinity risks for rice production in the Vietnamese Mekong Delta. Field Crops Research, 236: 111-120. [doi: https://doi.org/10.1016/j.fcr.2019.03.007]
Floodplains ; Salinity ; Agricultural production ; Paddy fields ; Rice ; Mapping ; Deltas ; Seasonal cropping ; Climate change ; Hydrological factors ; Risk analysis / Vietnam / Mekong Delta
(Location: IWMI HQ Call no: e-copy only Record No: H049182)
(3.98 MB)
The rationale for mapping hydrological risks in the Mekong River Delta (MRD) is the large extent of flood-affected and salinity-affected areas that severely constrain rice production. This new study on risk mapping expands previous approaches in depth (resolutions of 300 × 300 m and 1 h) and width (combining different types of maps). Data obtained with a hydrological model have been evaluated through four different methods of mapping individual attributes of risks that collectively comprise a comprehensive risk assessment for rice production: 1) Peak risk maps: These maps show the maximum water heights in a high-water year and maximum salinity concentrations in a low-water year. 2) Time-sequenced risk maps: The article provides hyperlinks to videos that encompass time-sequenced maps for the critical periods of floods (July-December in daily intervals) and salinity (March-April in hourly intervals) for all provinces. 3) Sustained risk maps (for rice): This approach is based on clearly defined thresholds of flood and salinity risks considering the duration of risk exposure at a given location. We have set thresholds for water heights exceeding 0.4 m and salinity concentrations above 2 g/l for 7 consecutive days to define start and end dates of sustained risks for rice. 4) Risk profile maps (for rice): The data on sustained risk have been aggregated at province level to calculate the geographic coverage of risk areas as compared with the total rice area. The rice area exposed to sustained flood risks in the MRD comprises 39% of the total rice area, which can be further subdivided into 24% with long (>three months), 12% with moderate (1–3 months), and 3% with short (1–4 weeks) risk duration. Likewise, the salinity-prone rice area accounts for 44% of the total rice area and can be subdivided into 31% with long, 8% with medium, and 5% with short risk duration. Finally, we have discussed the pros and cons of these different risk mapping methods in view of required adaptation strategies for rice production to cope with rapidly changing environmental conditions.
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