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

Flood hazards have led to substantial fatalities and economic loss in the last five decades, making it essential to understand flood dynamics in a warming climate. This study reports the first comprehensive assessment of projected flood hazards across Vietnam. We used downscaled climate data from th...

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Main Authors: Hong Xuan Do, Tu Hoang Le, Manh-Hung Le, Dat Le Tan Nguyen, Nhu Cuong Do
Format: Article
Language:English
Published: MDPI AG 2024-02-01
Series:Water
Subjects:
Online Access:https://www.mdpi.com/2073-4441/16/5/674
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author Hong Xuan Do
Tu Hoang Le
Manh-Hung Le
Dat Le Tan Nguyen
Nhu Cuong Do
author_facet Hong Xuan Do
Tu Hoang Le
Manh-Hung Le
Dat Le Tan Nguyen
Nhu Cuong Do
author_sort Hong Xuan Do
collection DOAJ
description Flood hazards have led to substantial fatalities and economic loss in the last five decades, making it essential to understand flood dynamics in a warming climate. This study reports the first comprehensive assessment of projected flood hazards across Vietnam. We used downscaled climate data from the CMIP6 initiative, involving a total of 20 climate models, and streamflow projection simulated using a semi-distributed hydrological model. The assessment covers seven near-natural catchments, each representing a climate zone of the country. To evaluate climate change impacts on floods, the study simultaneously analyzes changes in three indices: (i) the annual hottest day temperature, to represent temperature extremes; (ii) the maximum daily rainfall amount, to represent rainfall extremes; and (iii) the discharge value exceeding 5% in a year, to assess streamflow extremes. Changes in the selected indices (relative to the reference period from 1985 to 2014) are assessed under four emission scenarios (SSP1–2.6, SSP2–4.5, SSP3–7.0, and SSP5–8.5) and two future time slices (2036–2065 and 2070–2099). Although the robustness (as indicated by multi-model agreement) and significance (identified through the statistical test) of the changes vary substantially, depending on the selected indices and assessed time slices, an overall increase is consistently identified across all of the assessed hydro-climatic extremes (up to 4.8 °C for temperature extremes, 43 mm for rainfall extremes, and 31% for streamflow extremes). The findings suggest a potential increase in flood risk across Vietnam in a warming climate, highlighting the urgent need for improved flood preparedness and investment to reduce economic loss and mortality in an uncertain future.
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spelling doaj.art-e3f92f4e38f842c5b40150d0716211e12024-03-12T16:57:38ZengMDPI AGWater2073-44412024-02-0116567410.3390/w16050674Future Changes in Hydro-Climatic Extremes across Vietnam: Evidence from a Semi-Distributed Hydrological Model Forced by Downscaled CMIP6 Climate DataHong Xuan Do0Tu Hoang Le1Manh-Hung Le2Dat Le Tan Nguyen3Nhu Cuong Do4Faculty of Environment and Natural Resources, Nong Lam University-Ho Chi Minh City, Ho Chi Minh City 721400, VietnamResearch Center for Climate Change, Nong Lam University-Ho Chi Minh City, Ho Chi Minh City 721400, VietnamHydrological Sciences Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USAFaculty of Management Sciences, Thu Dau Mot University, Binh Duong 820900, VietnamSchool of Architecture and Civil Engineering, University of Adelaide, Adelaide, SA 5005, AustraliaFlood hazards have led to substantial fatalities and economic loss in the last five decades, making it essential to understand flood dynamics in a warming climate. This study reports the first comprehensive assessment of projected flood hazards across Vietnam. We used downscaled climate data from the CMIP6 initiative, involving a total of 20 climate models, and streamflow projection simulated using a semi-distributed hydrological model. The assessment covers seven near-natural catchments, each representing a climate zone of the country. To evaluate climate change impacts on floods, the study simultaneously analyzes changes in three indices: (i) the annual hottest day temperature, to represent temperature extremes; (ii) the maximum daily rainfall amount, to represent rainfall extremes; and (iii) the discharge value exceeding 5% in a year, to assess streamflow extremes. Changes in the selected indices (relative to the reference period from 1985 to 2014) are assessed under four emission scenarios (SSP1–2.6, SSP2–4.5, SSP3–7.0, and SSP5–8.5) and two future time slices (2036–2065 and 2070–2099). Although the robustness (as indicated by multi-model agreement) and significance (identified through the statistical test) of the changes vary substantially, depending on the selected indices and assessed time slices, an overall increase is consistently identified across all of the assessed hydro-climatic extremes (up to 4.8 °C for temperature extremes, 43 mm for rainfall extremes, and 31% for streamflow extremes). The findings suggest a potential increase in flood risk across Vietnam in a warming climate, highlighting the urgent need for improved flood preparedness and investment to reduce economic loss and mortality in an uncertain future.https://www.mdpi.com/2073-4441/16/5/674climate changehydrologic modelfloodsCMIP6
spellingShingle Hong Xuan Do
Tu Hoang Le
Manh-Hung Le
Dat Le Tan Nguyen
Nhu Cuong Do
Future Changes in Hydro-Climatic Extremes across Vietnam: Evidence from a Semi-Distributed Hydrological Model Forced by Downscaled CMIP6 Climate Data
Water
climate change
hydrologic model
floods
CMIP6
title Future Changes in Hydro-Climatic Extremes across Vietnam: Evidence from a Semi-Distributed Hydrological Model Forced by Downscaled CMIP6 Climate Data
title_full Future Changes in Hydro-Climatic Extremes across Vietnam: Evidence from a Semi-Distributed Hydrological Model Forced by Downscaled CMIP6 Climate Data
title_fullStr Future Changes in Hydro-Climatic Extremes across Vietnam: Evidence from a Semi-Distributed Hydrological Model Forced by Downscaled CMIP6 Climate Data
title_full_unstemmed Future Changes in Hydro-Climatic Extremes across Vietnam: Evidence from a Semi-Distributed Hydrological Model Forced by Downscaled CMIP6 Climate Data
title_short Future Changes in Hydro-Climatic Extremes across Vietnam: Evidence from a Semi-Distributed Hydrological Model Forced by Downscaled CMIP6 Climate Data
title_sort future changes in hydro climatic extremes across vietnam evidence from a semi distributed hydrological model forced by downscaled cmip6 climate data
topic climate change
hydrologic model
floods
CMIP6
url https://www.mdpi.com/2073-4441/16/5/674
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