Spatial metrics modeling to analyse correlations between urban form and surface water drainage performance.

Cities exhibit unique spatial patterns, and thus a distinctive heterogeneity. At different scales of influence, they introduce changes in the physical properties of the natural environment, as the diffusion of impervious surfaces. While climate change is expected to increase the frequency of hazards, patterns of urbanization might be critical in balancing the exposure of cities to extreme weather events, such as heavy rainfalls. Therefore, the adaptability of urban structures to stormwater management measures is vital to safeguard cities against increasing flooding. Yet, planning and design practices are challenged to address the resiliency of urban developments. There is necessity for a new set of planning tools able to assess the performance of specific spatial patterns on the meso-scale level to extreme stormwater events. This study describes a new hydrologic model designed to analyse the spatial configuration of the urban landscape and local distribution of natural drainage sites, identifying flood prone areas in densely urbanized districts. Initial experiments on case-study cities has been develop to determine the behavior, outcomes and robustness of the model. Although further research needs to be performed, the use of spatial metrics, in assessing future developments, has a strategic role in bringing together urban planning and flood impact reduction.