Climate change is a global environmental challenge, but its implications are often felt regionally. Several scientific assessments reveal that it is the possible cause of the intensification of extreme climate events, and the situation is getting more severe than ever (e.g. Lindner et al. 2010; Pramanik et al. 2021). In the context of droughts, climate change affects the hydrological cycle owing to increased radiative forcing, which causes an increase in temperature and evaporation (Trenberth 1999). Across many places around the world, climate change has already affected the total annual precipitation and the seasonal dynamics (IPCC 2007; Pramanik et al. 2018), including extreme climate events, such as heavy storms, heat waves, rainfall, flood and droughts, often with increasing intensity and frequency (IPCC 2007). As such, the impacts of climate change can be examined by analyzing observed data (Thanvisitthpon et al. 2018); and from climate projections at the regional level by downscaling General Circulation Models and Regional Climate Models (Aslam et al. 2020; Dash et al. 2019).
In Vietnam, drought is one of the most frequent and widespread natural hazards after the flood, storm, and has become more severe in recent years owing to climate change (Vu et al. 2015). Drought severity varies across various regions of Vietnam in terms of timing, underlying causes, damage and spatial extent (Vu et al. 2015). Several assessments (e.g. Dasgupta et al. 2009) revealed that Vietnam- and in particular the Mekong Delta- is highly susceptible to climate change. According to Global Facility for Disaster Reduction and Recovery Vietnam ranks among the five countries likely to be most affected by climate change (GFDRR 2010). Similarly, according to the climate risk index of Germanwatch Vietnam ranked 6th among the high-risk countries (Eckstein et al. 2019).
The Mekong Delta is a low lying and flat terrain located downstream of the Mekong River, with crisscrossing rivers and canals. The Mekong Delta of Vietnam suffers from sub-optimal agriculture production due to the impacts of climate change (Huynh et al. 2020). As a result, water shortages and drought are most often associated with salt-water intrusion in all cropping seasons in the Mekong region (Vu et al. 2015). Therefore, even with marginal changes in the climate, it will significantly influence agriculture production as well as the economy, ecosystems, and people’s livelihoods. Huynh et al. (2020). Ty et al. (2015) and GFDRR (2017) showed that drought has become more severe and persistent in many parts of Vietnam, including the Mekong delta.
The Standardized Precipitation Index (SPI) is both a probabilistic and a standardized drought index. The Standardization of the drought index ensures that the index in question is independent of its geographical consideration concerning average precipitation (Bordi and Sutera 2007; Vu et al. 2015). In Asia, particularly in Vietnam, many researchers have adopted this index as an efficient and useful tool for drought monitoring at the regional as well as the national scale (Huynh et al. 2020; Udmale et al. 2020; Vu et al. 2015). The impact of climate change on drought is complex and challenging to assess because it depends on many climate factors, including land and sea surface temperature, water resources and rainfall pattern (Huynh et al. 2020). Several modelling approaches can be used to estimate future climate; however, the estimation accuracy depends mainly on the quality of hydrogeological and climatic data.
Apart from that, people's perception and adaptive capacity to climate change in general and drought, in particular, varies between the areas. At the management level, assessing and quantifying climate change impacts on drought is one of their greatest concerns because it can support them in preparing mitigation and adaptation strategies to reduce climate change consequences. Till date, there have been various researchers evaluating the impacts of climate change on drought in central Vietnam with considering very limited data and not focused on the detail of its implications. Besides this, there is no such studies were undertaken for the detailed analysis of the local level perception and adaptation strategies with a specific focus on gap analysis of drought management over the region. It is; therefore, the present study intends to fill the research gaps by evaluating the climate change impacts on drought (2020–2050), the perception of local farmers about drought, and the coping and local adaptation strategies by drought-affected rural households in the Mekong region, particularly in Tien Giang province in Vietnam. A stronger focus on the local implications of global climate change models, suitable adaptation strategies will be particularly useful for water and agriculture management agencies and policy-makers to assess practical measures to cope with climate change and drought conditions in future.