Strategic Land-Use Planning in a Changing Climate—Adapting to the Spatial Dynamics of Risk in Ho Chi Minh City

For Asian cities situated within mega-urban coastal regions, such as Ho Chi Minh City, there is a pressing need for adaptation to climate change to focus on minimising exposure and reducing vulnerability by increasing urban resilience to the future impacts of climate extremes. Scientifically predicted are the direct impacts of climate change on populations (i.e. by urban flooding) and the indirect effects through impacts on climate-sensitive urban sectors (i.e. housing, energy supply systems). Geographic context gives rise to the biophysical exposure, which includes factors such as topography, connectivity and urban structures, all of which can be mediated by spatial planning or construction technologies. Further the urban fabric underlies the patterns of social vulnerability, including issues such as population density, levels of income and education as well as institutional capacities. Here spatial planning measures to enhance adaptive capacity should be directed towards decreasing biophysical exposures and the social vulnerability from the viewpoint of place-based risk assessments. Key urban impact and vulnerability indicators vary considerably from settlement to settlement and even within settlements. The location, the built urban structures, the dominant building types, the social-economic characteristics and institutional capacities are all highly dynamic factors with an important spatio-temporal dimension that affects ultimately the overall exposure, vulnerability and environmental performance of a settlement. Rapid urbanisation driven by fast changes in socioeconomic development conditions are the key factors influencing the future levels in both exposure and vulnerability to climate extremes. Our impact assessment study highlights, that the influence of non-climatic stressors—like urbanisation as the spatial manifestation of socio-economic processes is still widely under acknowledged. Traditionally only snapshots of the current urban situations have been partially integrated into risk assessments, resulting often, for highly dynamic urban regions, in an overestimation of climate extremes as a stressor of risk. An urgent need has arisen to readdress and improve the scientific methods and datasets to examine these key non-climatic drivers of future urban risk and to assess their relative importance for risk propagation compared to primary changes in climate. The most significant issue here is the integration of the future dynamics of urban development processes.