Socio-hydrological complexity in the Vietnamese Mekong Delta: a systematic review and recent empirical findings from the floodplains of An Giang province

Abstract:

Current water management practices are facing multiple challenges due to the complexity of the human-water system and from the uncertainties of climate change. Our study aims to discover the characteristics and the co-evolution between human and hydrological systems in the floodplain of the Vietnamese Mekong Delta (VMD). We employ a systematic literature review supported by surveys of 100 farmers to explore how the development of different dike systems in the four zones of An Giang province has led to differences in farmers’ perceptions of flooding and livelihood transformation. Our results indicate that the contrasting use of high dike systems in the study zones has led to significant changes in farmers’ perceptions on various aspects of flooding and livelihoods. For example, while a majority of respondents in Zones 1 and 2 (60% for both) indicated that the flood season has started later with the dike changes, a majority of farmers in Zone 3 (52%) indicated an unchanged flood season, and a similar percentage of respondents in Zone 4 either thought that the flood season remains unchanged or starts later (44%). We also found significant differences between the zones in farmers’ explanations for changes in flood timing including climate change and upstream activities. In addition, farmers in different zones had contrasting perceptions of changes in recent flood peaks compared with peak flows before the dike changes, and there were significant differences between the zones on whether farmers perceived that these changes are due to either upstream activities or climate change. Within the science, Socio-hydrology, several phenomena have been identified including “pendulum swings”, “levee effects” and “adaptation effects”. While the synthesis of case studies shows some common dynamics, the existing number of empirical research studies is insufficient to conclude whether the phenomena commonly exist. The VMD is facing multiple water-related threats that profoundly challenge the practices of land-water management in the region, especially given the hierarchical political context. A better understanding of the co-evolution of social-ecological systems through a Socio-hydrological perspective in the VMD could help policymakers formulate effective management plans tailored to the different agro-ecological zones.