Space–time variability of drought over Vietnam

Le, Phuong Thu; Phan-Van, Tan; Khiem, Van; Tran, Duc Quang

doi:10.1002/joc.6164

Cited by 41 publications

(30 citation statements)

References 48 publications

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“…The drought periods described above are in accordance with the study of Le and colleagues [35], who used monthly precipitation and 2 m air temperature observations for the period 1980-2014 obtained from 131 meteorological stations across mainland Vietnam to calculate PDSI. However, these authors [35] found that in the S5 region the dry conditions were more intense than in the other regions of the country, and this is not clearly noticeable in our results.…”

Section: Drought Conditionsmentioning

confidence: 90%

“…Some studies have highlighted that droughts have become unusually more frequent and severe worldwide, such as in the Mediterranean region [21][22][23], Europe [24][25][26], West Africa [27,28], and Asia, including Vietnam [20,[29][30][31][32][33][34][35]. Recent conclusions of the Intergovernmental Panel on Climate Change (IPCC) show much evidence that climate change affects many regions in Southeast Asia, one of the most vulnerable regions in the world [36,37].…”

Section: Introductionmentioning

confidence: 99%

“…Vietnam is likely to be one of the countries most affected by climate change because of its long coastline and strong reliance on agriculture, natural resources, and forestry [34,[38][39][40][41]. Few publications have investigated the characteristics of droughts in this region (e.g., [32,35,[42][43][44][45]). Tue and co-authors [32] investigated drought over the Central Highland using the Standardized Precipitation Index (SPI) with different observed and modeled monthly precipitation datasets for the period 1990-2005.…”

Section: Introductionmentioning

confidence: 99%

“…Their results showed that regional climate models data successfully captured the spatial structure of the SPI; in particular, the severe drought events of 1998 and 2005. For a longer study period, Le et al [35] studied the spatio-temporal variability of drought in Vietnam for the period 1980-2014, but using the Palmer Drought Severity Index (PDSI). Their results showed regional patterns of drought duration, frequency, and severity, but no consistent trend of drought during the study period.…”

Section: Introductionmentioning

confidence: 99%

“…Annual mean temperatures in southern regions are rising quicker than in the northern ones. The concern arises if we also consider that besides the precipitation, high temperatures also modulate the occurrence of droughts [35]. An impact assessment based on climate change scenarios (precipitation and temperature) for the Lower Mekong River Basin for the period of 2016-2040 [54] indicates an increase in temperature and a decrease in precipitation in the near future, significantly decreasing the streamflow and soil water content, while drought characteristics in terms of severity, duration, and frequency are projected to be increased.…”

Section: Introductionmentioning

confidence: 99%

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Trends and Extremes of Drought Episodes in Vietnam Sub-Regions during 1980–2017 at Different Timescales

Stojanović

Liberato

Sorí

et al. 2020

Water

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This study investigated the temporal occurrence of dry conditions in the seven climatic sub-regions of Vietnam during the 1980–2017 period. This assessment was performed using the Standardized Precipitation Evapotranspiration Index (SPEI) and the Standardized Precipitation Index (SPI) at 1 to 24 months timescales. Results show that the main periods of extreme drought occurred simultaneously throughout the country in 1992–1993 and 2003–2004, except for 2015–2016, when it was not identified in the southern region. In addition, a slight temporal lag was identified latitudinally (north–south) at the beginning of dry conditions, revealing the largest difference between the northern and southern regions. A positive trend in the time series of both indices (SPEI and SPI) prevailed in all sub-regions, with the SPEI minus SPI difference always being negative, suggesting the importance of temperature and evapotranspiration for this trend. Further detailed analyses were then performed using SPEI at 1-month and 12-months timescales for all climate sub-regions, as well as the main indicators to characterize duration and severity. Results show that the number of drought episodes did not vary much between regions, but they did vary in duration and severity at the annual scale. Moreover, changes in the soil root zone are largely associated with dry and wet conditions not only from season to season, but also in longer accumulation periods and more strongly in the northern regions of Vietnam. Indeed, a study of the most severe drought episodes also revealed the occurrence of negative anomalies of the root-soil moisture in the subsequent four or more months. Dynamic atmospheric conditions associated with the peak of most severe drought episodes show the crucial role of subsidence of dry air in the middle and high atmosphere, which prevents convection in the lower troposphere. Finally, the linkages between drought conditions in Vietnam and large-scale atmospheric and oceanic teleconnection patterns were revealed to be quite different among northern and southern sub-regions. During the positive phase of El Niño–Southern Oscillation (ENSO), drought episodes at different timescales were identified in the southern climate sub-regions, while the negative phase was associated with drought conditions in the northern regions.

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Section: Drought Conditionsmentioning

confidence: 90%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Trends and Extremes of Drought Episodes in Vietnam Sub-Regions during 1980–2017 at Different Timescales

Stojanović

Liberato

Sorí

et al. 2020

Water

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Projected evolution of drought characteristics in Vietnam based on CORDEX‐SEA downscaled CMIP5 data

Nguyen-Ngoc-Bich

Phan-Van

Ngo‐Duc

et al. 2021

Intl Journal of Climatology

Self Cite

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In this study, the projected drought characteristics over Vietnam for the future periods of the middle (2046–2065) and end of the 21st century (2080–2099) were investigated under the Representative Concentration Pathway (RCP) scenarios RCP4.5 and RCP8.5. The drought characteristics (duration, severity, intensity, inter‐arrival time, and geographic extent) were estimated based on the Palmer Drought Severity Index (PDSI). The PDSI was calculated using temperature and precipitation data from six regional climate downscaling experiments and their ensemble conducted by the Coordinated Regional Climate Downscaling Experiment‐Southeast Asia (CORDEX‐SEA) project. Projected changes of drought characteristics in the future periods were determined with respect to those in the baseline period 1986–2005. Results show biases in the regional climate model (RCM) outputs, namely an underestimation of temperature and an overestimation of precipitation, which also affect the representation of drought characteristics by overestimating the PDSI. In terms of projections, substantial increases of drought duration, severity and intensity, and decreases in the inter‐arrival time are found over the Red River Delta, northern parts of the North Central sub‐region, parts of the Central Highlands and over southern Vietnam. The droughts are projected to be more widespread under scenario RCP8.5 than RCP4.5, especially in southern Vietnam. With the increasing likelihood of droughts in Vietnam as a result of climate change, sustainable water resources management should be taken into account for agriculture, natural ecosystems and social development.

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Tracking the origins of moisture over Vietnam: The role of moisture sources and atmospheric drivers on seasonal hydroclimatic conditions

Stojanović

Nieto

Liberato

et al. 2021

Intl Journal of Climatology

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A Lagrangian approach is used to identify the seasonal climatological moisture sources of the seven climate subregions of Vietnam during 1980–2017. Using the outputs from the FLEXPART model, three main oceanic moisture sources, located in the Arabian Sea, Bay of Bengal, and China Seas, and three terrestrial moisture sources, located in the Indian Peninsula, East Asia, and South Asia, are identified. The most important moisture source during the rainy season (May–October) is the Bay of Bengal, followed by the East Asia continental source for the North‐East and North Plain subregions, while for the remaining sub‐regions Arabian Sea is the main source. For the dry season (November–April), the China Sea supplies more than the half of the total moisture over almost all subregions, while the continental South Asia source is the primary one for the North‐West subregion. The moisture contributions from oceanic moisture sources are the major contributions to the Vietnam subregions, except for the North‐West subregion where the terrestrial sources form the major percentage. Severe and extremely dry conditions are identified for both the rainy and dry seasons in all subregions using the 6‐month Standardised Precipitation Evapotranspiration Index (SPEI6), and a positive significant linear relationship is found between the SPEI6 time series and the anomalies of moisture contribution from the sources. Thus, for both seasons, a reduction in moisture supply from the most important sources is found during severe and extreme droughts. The dependence on ENSO phase is also assessed. Finally, although the correlations are not statistically significant, we found that the rainy (dry) season in the northern subregions show a tendency towards wetting (drying), while the opposite was found for the southern subregions. This behaviour is consistent with the trends observed in precipitation, potential evapotranspiration, and moisture contribution values from the different sources.

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Space–time variability of drought over Vietnam

Cited by 41 publications

References 48 publications

Trends and Extremes of Drought Episodes in Vietnam Sub-Regions during 1980–2017 at Different Timescales

Trends and Extremes of Drought Episodes in Vietnam Sub-Regions during 1980–2017 at Different Timescales

Projected evolution of drought characteristics in Vietnam based on CORDEX‐SEA downscaled CMIP5 data

Tracking the origins of moisture over Vietnam: The role of moisture sources and atmospheric drivers on seasonal hydroclimatic conditions

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