Building geometry strongly influences pedestrian comfort and safety, especially in dense urban environments. As urbanization increases and cities continue to develop, understanding how building arrangement affects pedestrian-level wind conditions becomes increasingly important for creating safe and comfortable outdoor conditions. In this thesis, the TU Delft campus was used as a case study to investigate how modifications in the spatial arrangement of buildings affect pedestrian-level wind conditions. By relocating groups of buildings within the campus area, a set of four hypothetical modified layouts was created and steady-state RANS simulations were performed for each layout. To assess pedestrian wind comfort, a combined exceedance criterion based on wind velocity and turbulent kinetic energy was used rather than the standardized wind comfort guideline NEN 8100. The results show that building rearrangement mainly redistributes discomfort zones, following the regions of high wind velocity and turbulence kinetic energy. The strongest effects occur in the places where layout modifications took place. The relocation of high-rise buildings is the dominant factor that determines the probability and the extent of the discomfort zones, with more exposed placements generally leading to a larger area of discomfort. While most layouts mainly redistribute the zones of high discomfort risk, one modified configuration shows the clearest improvement in pedestrian wind comfort in the main central open area of the campus. For a critical wind direction that produces the highest wind speeds in the main open space of the campus, an additional blockage-ratio analysis was performed. The results indicate that local wind velocity in the region responds to upstream geometric blockage, with higher frontal blockage generally associated with lower wind velocity. Overall, these findings highlight the important role of building design in shaping pedestrian-level wind flow and provide useful insight for improving pedestrian comfort in urban spaces. ... Read more

Due to quick population growth and urbanisation in Kumasi, Ghana, groundwater depletion is accelerating, and land cover changes reduce the rate of natural infiltration. A promising measure to combat rapid aquifer depletion is implementing Managed Aquifer Recharge (MAR), by rooftop rainwater harvesting and pumping this into wells. The objective of this paper is to delineate the (qualitative) impact of precipitation through Managed Aquifer Recharge on the groundwater level, by analyzing groundwater level changes of sites with and without MAR around Kumasi. To achieve this, multiple groundwater level and flow models have been constructed over different time periods with varying temporal resolutions to show the short- and long-term effect of precipitation on the groundwater level on sites with and without MAR. A rapid increase of groundwater level is observed during rain events, followed by a decelerating curve of infiltration towards areas with lower elevations. This dissipation is much faster in areas with high hydraulic conductivity (hours) than with low hydraulic conductivity (weeks). The groundwater level is recharged by MAR less in the dry season than in the wet seasons. MAR has a highly positive influence on the groundwater recharge. It will be most crucial to implement MAR in high elevations, where the overburden has low hydraulic conductivity, as natural recharge is limited here. The lack of soil and hydraulic head data limited the reliability of the models. Therefore, it is recommended to extend the database in these and additional research areas, aiming to differentiate the effect of MAR and the natural infiltration on the hydraulic head level. ... Read more