Adaptive capacity of high- and low dyke farmers to hydrological changes in the Vietnamese Mekong delta

Chapter 16 - Farmers’ livelihoods and adaptation in the Vietnamese Mekong Delta: Current practices and policy implications

Tribal farmers are most vulnerable to climate variability and change (CVC) due to their climate sensitive livelihoods and lack of resources to afford the adaptation measures. In order to formulate appropriate programs and policies addressing climate change, it is essential to understand their adaptive capacity (AC). This study analyzed the level of adaptive capacity (AC) of tribal dairy farmers’ households of Himachal Pradesh, part of western Himalayan region (one of the fifteen agro-climatic zones in India), and confronting the factors that cause the differences in AC. Based on the previous studies, AC of each household was determined by developing a composite “Adaptive Capacity Index (ACI) by using method of Principal Component Analysis (PCA) with the help of statistical software SPSSv21. ACI was developed underlying the definition of adaptive capacity (AC) as put forward by IPCC (2007), consisting of five index components namely human capital, physical capital, financial capital, social capital and natural capital. Results showed that variations in AC were caused by differences in human capital, physical and financial capital. Tribal households that scored low in these three indicators had lower adaptive capacity (AC). ACI indicated that the most of the tribal dairy farmers (31.88%) of sampled region have low level of AC score category with wide variation in ACI components across the villages and households, which are highly vulnerable to CVC. Naurangabad village of Sirmaur district have lowest score (0.70±0.03) of ACI among the entire selected village. To cope up the adverse climatic conditions and for the sustenance of dairy farming in the study area, the appropriate climate resilient policies will be required for incentivizing the livelihoods infrastructure, promotion of grass root level innovations and to increase AC of tribal dairy farmers by using locally available resources.

Environmental challenges in the Vietnamese Mekong Delta characterized by adverse impacts of climate change, upstream hydropower development and localized dyke expansion present imperatives for rural farmers to “learn to adapt.” However, little is known about how learning contributes to improving their capacity in adapting to these “wicked” problems. This study investigates potential effects of farmers’ learning on their adaptive capacity, utilizing nine focus group discussions, 33 interviews, and a structured survey of 300 farmers. The exploratory factor analysis produced two factors for social learning: (1) learning through social interactions and (2) self-reflection, and one factor for adaptive capacity. The regression results show that the social learning factors have significantly positive effects on adaptive capacity. Farmers with a higher level of social learning are likely to demonstrate higher adaptive capacity. The findings call for policy considerations to promote learning in a broader context of the delta to enhance local capacity.

Flood dynmics in the Vietnamese Mekong Delta : Current state and future projections

Assessment of adaptive capacity and adaptation to climate change in the farming households of Eastern Himalayan foothills of West Bengal, India

BackgroundAn increasing severity of extreme storms and more intense seasonal flooding are projected consequences of climate change in the United States. In addition to the immediate destruction caused by storm surges and catastrophic flooding, these events may also increase the risk of infectious disease transmission. We aimed to determine the association between extreme and seasonal floods and hospitalizations for Legionnaires’ disease in 25 US states during 2000–2011.MethodsWe used a nonparametric bootstrap approach to examine the association between Legionnaires’ disease hospitalizations and extreme floods, defined by multiple hydrometeorological variables. We also assessed the effect of extreme flooding associated with named cyclonic storms on hospitalizations in a generalized linear mixed model (GLMM) framework. To quantify the effect of seasonal floods, we used multi-model inference to identify the most highly weighted flood-indicator variables and evaluated their effects on hospitalizations in a GLMM.ResultsWe found a 32% increase in monthly hospitalizations at sites that experienced cyclonic storms, compared to sites in months without storms. Hospitalizations in months with extreme precipitation were in the 89th percentile of the bootstrapped distribution of monthly hospitalizations. Soil moisture and precipitation were the most highly weighted variables identified by multi-model inference and were included in the final model. A 1-standard deviation (SD) increase in average monthly soil moisture was associated with a 49% increase in hospitalizations; in the same model, a 1-SD increase in precipitation was associated with a 26% increase in hospitalizations.ConclusionsThis analysis is the first to examine the effects of flooding on hospitalizations for Legionnaires’ disease in the United States using a range of flood-indicator variables and flood definitions. We found evidence that extreme and seasonal flooding is associated with increased hospitalizations; further research is required to mechanistically establish whether floodwaters contaminated with Legionella bacteria drive transmission.

Saltwater intrusion is one of the main problems in the coastal provinces in the Mekong Delta (including the Tra Vinh province), and it is becoming more severe with climate change and rising sea levels. In the face of this problem, a strategic plan has been developed for the Vietnamese Mekong Delta that suggests adapting to increasing salinity levels. However, the farmers’ capacity to implement the changes is unclear. The objective of this study was to assess farmers’ adaptive capacities towards saline intrusion in the Tra Vinh province in order to provide appropriate adaptation options, using the MOTA (Motivation-Ability) approach. This study surveyed 187 farmers regarding their perception, motivation, and ability in different saline environments in the study area, including three regions: seawater areas (region 1), brackish water areas (region 2), and freshwater areas (region 3). The results showed that farmers have quite high perceptions of salinity intrusion, especially farmers who live in areas affected by it. Regarding the level of saltwater intrusion, the farmers’ motivation in all three regions had a negative score, which indicates their motivation for adapting to increased salinity was quite low. Additionally, the farmers’ adaptive capacities in all three regions were moderate, with lowest capacities in educational level and rate of participation in non-agricultural organizations. The study results may be useful for managers and policy-makers in proposing appropriate and feasible options for implementing an adaptation plan to ensure sustainable livelihoods for local farmers.

Understanding adaptive capacity of smallholder African indigenous vegetable farmers to climate change in Kenya

The Vietnamese Mekong Delta (VMD) has an important role in terms of food security and socio-economic development of the region. The VMD is a densely populated area and is a social and economic hotspot for coastal hazard risks and vulnerability. The amount of people exposed to flooding, storm surges and seasonal river floods in VMD is estimated to increase as the sea level rises, land-use changes and urbanization in flood-prone areas is growing. Therefore, it is necessary to focus on assessing and mapping flood hazard, risk and vulnerability of the Mekong delta. There are many flood hazard and risk studies carried out in the VMD, however very little is done with respect to vulnerability. The region is facing a rapid economic growth and vulnerability to floods becomes an important issue to be addressed.The study presented here focuses on mapping of the vulnerability of the VMD, based on the situation in the area and on the available data. The study evaluates the VMD districts from vulnerability point of view and presents maps, which will be helpful to the decision makers who need to take measures on how to reduce and mitigate the flood impact in the area. Collaboration between deltas' administrations, multiple stakeholders and organizations, at national and international level (delta alliances), has to be undertaken to support the most vulnerable areas and to learn from each other. Mapping vulnerability offers the opportunity to get a broad overview on affected areas and on possible adaptation options that could be applied, directing resources at more in-depth investigation of the most promising adaptation strategies. Moreover, at a later stage, it can also serve to evaluate the effectiveness of the adaptation measures.The present study presents a map of flood vulnerability for the VMD for the years 2000 and 2050 (see Main Map). The map is created by applying Coastal Cities Flood Vulnerability Index (CCFVI) methodology; the flood map will overlay flood hazard in order to create flood risk maps using tools such as ArcGIS.

Abstract. Regarding to the important environmental issues, eco-balance and eco-system should be discussed using long period data analysing and visible result of study. These visible results will be materials for construction of geo-design of the river basin. Both hydrological changes and surface changes of the Mekong delta was analysed with new data using hydrologic model with visible mapping in this study. The Mekong River delta, the third largest delta in the world, is presently shifting from growing to shrinking with its ecosystem and environment seriously degraded. These environmental changes are due to several factors such as 1)ill-planned water management schemes including hydropower dams in the river basin, 2) sediment starvation, 3) increased nutrient inflows, in combination with other human activities including infrastructural extension, riverbed mining, delta subsidence, degradation of coastal mangrove belt, and gaps in governance in the whole Mekong basin under the climate change and sea level rise. Both scientific and management communities have suggested that the rate of Mekong delta shrinking will increase markedly this century. The paper compiled new data and mapping together with recent key studies implying that much of the degradation in the Vietnamese Mekong delta is due to recent human activities, particularly hydropower dams in the entire Mekong river basin.By comparison with period before 1990s when there were no large dams, the natural regime here has changed with the annual sediment load to the delta having decreased by 50–60%, the flood discharges have also decreased, the hydrological seasonal regime has shifted as most of the Mekong River water is now trapped in these large dams, and the salinity intrusion into the delta now occurs earlier by 20–30 days. Further, the river bed is on the average deeper by 0.14 m, to which riverbed mining also contributes. There has been a recent increase of erosion of river banks at 400 locations and coasts. The 66% of all of foreshore is now eroding, and the rate of these events is accelerating with time. If all the proposed mainstream hydropower dams in the Lower Mekong Basin have been built, then the Vietnamese Mekong delta with its ecosystems and about 18 million people face critical issues of sustainability. This presentation also focused on some remedial conceptual solutions that may decrease, but not eliminate, the negative impacts of these dams for the Vietnamese Mekong delta. Non-engineering solutions have the highest propriety, but engineering solutions are needed for protecting eroded coastal foreshore, river bank erosion and the fragile mangrove belt. Toward to realization of SDG’s in this study region, the integrated management system of the river basin would be desired.

An approach for assessing adaptive capacity to climate change in resource dependent communities in the Nikachu watershed, Bhutan

ABSTRACTThe Vietnamese Mekong Delta (VMD) is one of the world’s most vulnerable deltas to climate change and sea level rise. Adequate understandings of future hydrological changes are crucial for effective water management and risk-proofing, however, this knowledge body is currently very limited. This study quantifies the responses of the VMD’s river flow regime to multiple stimuli, namely future upstream inflow variation, local climate change, and sea level rise. The one-dimensional hydrodynamic model MIKE 11 was used to simulate discharges and water levels across the delta. We developed four scenarios to represent changes in the upstream discharges, precipitation changes and sea level rise, covering the 2036–2065 period. We downscaled climate data and applied three bias-correction methods for five General Circulation Models (GCM), and two Representative Concentration Pathways (RCPs). The climate change projections show similar trends of increasing wet season precipitation and decreasing dry season precipitation. However, cross-scenario variations are sometimes large, depending on the individual GCMs, the RCPs and specific locations. The hydraulic simulation results indicate that, under discharge changes between −20% and +10%, combined with in-delta precipitation variations during the dry season, river discharges at the four representative stations could reduce substantially from −2.5% to −100.2%. During the wet season, the calculated river discharges show increase between 7.3% and 46.7% under four considered scenarios. Substantial changes in the VMD’s river flow regime could have potentially serious implications for water management, especially saltwater intrusion, and therefore calling for timely adaptation measures.

The Vietnamese Mekong Delta (VMD) comprises extensive river and canal networks, both natural and man‐made, and has a history of extensive land use change and development. The delta's wetlands are under considerable ecological stress because of hydrological changes, agricultural and aquaculture development, urban and industrial pollution, climate change, and upstream water resource development. In this paper, we review the current threats and challenges to the conservation and management of the wetlands in the VMD. We recommend that the current water management practices of the Ramsar‐listed Lang Sen Wetland Reserve are changed so that the natural flood regimes are reinstated and the risks to the community from forest fires are managed. Ongoing investment is needed to support further research, set up long‐term monitoring, and to develop hydrodynamic models for the Lang Sen Wetland Reserve so that management and conservation efforts can achieve the specific objectives for the wetland. This approach may be useful for managing other wetlands across the VMD.

Climate change poses increasing challenges to rural communities, including Margorukun Village in West Papua, where local livelihoods are highly dependent on natural resources. Strengthening community adaptive capacity is therefore essential for enhancing resilience to climate-related impacts. This study aims to assess sustainable livelihood assets and evaluate the community's adaptive capacity to climate change. Data were collected from 58 households (10% of the village population) using a mixed-methods approach combining household surveys, semi-structured interviews, and policy review. Sustainable livelihood assets were analysed using Likert-scale scoring, while adaptive capacity was assessed using the Adaptive Capacity Wheel (ACW) framework. The results indicate that natural capital was the strongest asset (67.38%), supported by land availability for farming, aquaculture, and livestock, whereas financial capital was the weakest (30.86%) due to subsistence-based livelihoods and limited access to financial services. Adaptive capacity varied across six dimensions, with variety scoring highest, reflecting diverse livelihood strategies, and fair governance scoring lowest, indicating unequal participation in decision-making. These findings highlight the importance of leveraging strong natural and social assets while addressing financial and institutional constraints to enhance community resilience to climate change.

In Integrated Assessment modelling of climate change impacts and adaptation, there are two main uses for measures of capacity to adapt to climate change. The first is to represent the capacity for proactive adaptation: this can be termed adaptive capacity. The second is to represent the capacity for reactive or instantaneous coping: this can be termed coping capacity. Adaptive capacity helps to determine which proactive adaptation options are feasible as inputs to the models under any given pair of climate and socio-economic scenarios. Coping capacity represents the residual ability to react to conditions, and influences vulnerability under any given set of model outputs. Using the example of the CLIMSAVE Integrated Assessment Platform, we explain how these capacities can be represented in integrated assessment. We demonstrate how an index of adaptive and coping capacity can be developed using a five-capitals (human, social, manufactured, natural, financial) model of societal wealth and incorporated in integrated assessment models. We find that for very aggregate applications, but not local or sectoral applications, the same indicators can be used to simulate adaptive and coping capacity. In addition, we argue that it is generally unnecessary to account for the depletion of capacity through adaptation itself, and that natural capital can generally be omitted from capacity measures if it is already directly represented in model outputs.