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Climate change is severely affecting all regions of the world, and urban water management has become a major urban challenge. Although nature-based solutions (NBSs) have been widely implemented in developed countries in the Global North to address stormwater-related challenges in urban areas, implementation of such approaches in Viet Nam and other Asian countries remains limited. In addition, comprehensive and critical reviews of NBS adoption and development processes in Viet Nam are scarce. This study aims to clarify several aspects through a literature-based review: to understand the development of urban water management in Europe and Asia (China and Southeast Asian countries) along with the drivers for NBS implementation in Viet Nam, to explain the barriers to NBS adoption in Viet Nam, to present feasible solutions for promoting NBS adoption, and to explore future perspectives for NBS development in the context of Viet Nam. Although significant barriers exist, opportunities for NBS implementation are evident. The findings of this study can be used to promote NBS in other municipalities in developing countries. [ABSTRACT FROM AUTHOR]

Urbanization alters land surface properties in absorbing, reflecting and emitting radiation as well as infiltrating, evaporating and storing water. This consequently modifies surface energy and water fluxes and, thus, urban climates. Weak synoptic flow, clear sky conditions and higher surface temperatures in cities compared to their rural surroundings create a buoyancy‐driven atmospheric circulation, in which surface energy fluxes become the main determinants of urban daytime overheating. Here, we demonstrate the role of surface energy fluxes for warming and cooling processes in the urban canopy layer under buoyancy‐driven atmospheric conditions. We improve and apply an integrated CFD‐GIS modeling approach to provide a detailed analysis of fine‐scale land‐atmosphere interactions and assess the surfaces' profound implications on energy and water exchange. We show that variations in the ratios of the surface energy fluxes to the net radiation can be separated from meteorological conditions (wind speed, air temperature and incoming solar radiation) and emissivity values, varying explicitly with changes in land surface type and water availability for vegetated areas. Based on the energy flux ratios, we introduce an approach to assess the surface‐induced warming and cooling effect and its contribution to urban overheating in the urban canopy layer, under buoyancy‐driven atmospheric conditions, directly applicable to strategic urban planning for climate change adaptation. Independent of meteorological conditions, this approach can be used to evaluate different surface materials (both natural and artificial) and climate adaptation measures, such as urban nature‐based solutions and blue‐green infrastructures, and to monitor changes in the energy and water balance. Plain Language Summary: The aim of this study is to better understand the impact of different surface characteristics (both natural and artificial) on soil‐surface‐atmosphere interactions and, consequently, on the urban meteorology. This is important to improve the assessment of climate change impacts and adaptation strategies in cities. We present an approach, directly applicable in strategic urban planning for climate change adaptation, that can describe the surface‐induced warming and cooling effect under low wind and clear sky conditions, when surface thermal forcing is the dominant factor in urban overheating. Separable from meteorological conditions (wind speed, air temperature and incoming solar radiation) and emissivity values, our approach can be used to rapidly evaluate changes to the surface characteristics, for example, through the implementation of urban nature‐based solutions and blue‐green infrastructure in cities. We highlight the importance of water availability in heat mitigation strategies to ensure evaporative cooling from green areas, and the hazardous potential of impermeable artificial surfaces to increase diurnal and nocturnal heat transfer. Key Points: Variations in the ratios of surface energy fluxes to net radiation separable from meteorological conditions and emissivity valuesA Bowen ratio lower than 0.52 for vegetated surfaces necessary to maintain a prevailing evaporative cooling effectLack of water from precipitation and irrigation exacerbates the heat transfer between the soil, surface and atmosphere [ABSTRACT FROM AUTHOR]