Impact of drought on household income in the Vietnamese Mekong Delta

Abstract In the Vietnamese Mekong Delta, droughts constitute one of the most critical challenges due to their significant adverse effects on household income. To improve the effectiveness of drought monitoring, it is necessary to analyze the impacts of drought across space, time, income sources, and income groups. The data used in the study are rainfall at weather stations, average income per capita by income quintile, by income source and by province. The methods used in the study were analysis of income differences between dry and wet conditions, correlation between income and drought index, and clustering. Compared to using the correlation coefficient, using the income difference between dry and wet conditions provides a clearer picture of the time when drought has a strong impact on income. When drought occurs during the period from the end of the dry season to the beginning of the rainy season, it will affect all income quintiles and income sources, and the Standardized Precipitation Index with a 3-month time scale (SPI3) and taken in April can be used to early assess the effects of drought on income of the year. The lowest quintile and farm income sources are most vulnerable to drought, and SPI6 taken in July is the most appropriate choice to assess the impact of drought. On average, the income of these groups is about 15% lower in dry years than in wet years. In addition, the study results also show that the impact of drought depends on the natural and social characteristics of each province. Provinces with poor irrigation water conditions, low urbanization rate and low urbanization growth rate are also provinces where the lowest quintile is vulnerable to drought.