Changes in Precipitation Extremes across Vietnam and Its Relationships with Teleconnection Patterns of the Northern Hemisphere

Abstract

Understanding changes in precipitation extremes is critical for designing mitigation measures for the potential implications of a warming climate. This study assessed changes in the magnitude and frequency of precipitation extremes over Vietnam using high-quality gridded daily precipitation observations from 1980 to 2010. The annual maxima precipitation was analyzed to detect historical changes in the magnitude of precipitation extremes, while the number of heavy precipitation events, defined using the peak-over-threshold approach, was used to assess changes in the frequency of precipitation extremes. We found a strong signal of changes in the frequency of heavy precipitation, with 28.3% of Vietnam’s landmass exhibiting significant increasing trends. The magnitude of annual maxima precipitation shows a mixed pattern of changes, with less than 10% of Vietnam’s landmass exhibiting significant (both increasing and decreasing) trends. To identify possible mechanisms driving changes in precipitation, we assessed the relationship between inter-annual variations in precipitation extremes and climate variability represented by the teleconnection patterns of the Northern Hemisphere. Using five climate indices, we found that teleconnections across the Indian and Pacific Oceans have implied large control over the characteristics of precipitation extremes across Vietnam, with up to 30% of Vietnam’s landmass exhibiting a significant relationship.

Influence of teleconnection patterns on global moisture transport during peak precipitation month

“…Although this analysis was based on monthly precipitation for the month with peak precipitation, in a climate change framework, analyses of extreme precipitation on a daily scale would be of special interest. Several studies have highlighted the increased influence of global teleconnection patterns on this kind of event (Casanueva et al ., 2014; Zecca et al ., 2018; Do et al ., 2020); this study establishes the basis of a methodology that could be extended in future research. The teleconnection pattern here analysed tries to establish a general overview at a global scale, however (as can be observed in Figure S6) they do not properly explain the variability in precipitation over many areas.…”

Future Changes in Hydro-Climatic Extremes across Vietnam: Evidence from a Semi-Distributed Hydrological Model Forced by Downscaled CMIP6 Climate Data

“…These catchments cover a wide range of attributes, for example, their catchment area ranges from 603 to 6392 km 2 , and areal percentages of forest land range from 6.2 to 84.9%. Each selected catchment is located entirely within a Vietnamese sub-climate region [40] including:…”

“…Water 2024, 16, x FOR PEER REVIEW 4 of 22 range from 6.2 to 84.9%. Each selected catchment is located entirely within a Vietnamese sub-climate region [40] including:…”

Precipitation and Soil Moisture Spatio-Temporal Variability and Extremes over Vietnam (1981–2019): Understanding Their Links to Rice Yield

“…Studies conducted on spatio-temporal patterns of precipitation in Vietnam so far have either been based on (i) irregularly-spaced in situ data [9][10][11] and/or fairly old gridded data [12,13], or (ii) dedicated to local study areas, such as one or several agro-ecological regions or provinces [14][15][16][17]. Studies focusing on spatial-temporal patterns of precipitation over Vietnam have been investigated in the literature [18,19], but similar studies on soil moisture are non-existent. Furthermore, most of the existing studies based on remotely-sensed data are not the most recent and are dedicated to local areas rather than the whole of Vietnam [20,21] and do not present the association of these variabilities to rice production.…”