Deconstructing urban flooding from the perspective of vulnerable communities in Northwestern Pakistan

The study aimed to deconstruct urban flooding in Peshawar (one of Pakistan's rapidly urbanizing cities) from the perspective of flood vulnerable communities. The research was conducted using a mixed-methods approach, synthesizing qualitative data with quantitative geospatial analyses of Land-Use/Land-Cover change and flood exposure. Qualitative data were collected through the Focus Group Discussion and In-depth Interviews checklist with a total sample size of 89 participants. The quantitative aspect (geospatial) was used to triangulate community-identified patterns (e.g., encroachment, land cover change). Study results reveal that the fast-increasing urban flooding phenomenon within Peshawar's rapidly urbanizing Bhudni Nullah Basin (BNB) is the outcome of a multifaceted and interrelated human-natural systems failures, driven by the merging of hydro-climatic conditions, anthropogenic modification and governance deficits. The basin's intensifying flood risk is fundamentally linked to impaired hydrological response resulting from rapid and unplanned urbanization. Erratic, high-intensity precipitation and an elevated water table critically diminish the basin's natural water retention and conveyance capacity. Geospatial analysis documented an increase in the artificial surface (impervious), surging from 39.60% in 2017 to 46.01% 2020 and eventually reached 59.96% in 2025. The transformation significantly accelerates surface runoff volume and velocity, overwhelming the existing drainage infrastructure. Unregulated riparian zone infringement and the persistent solid waste dumping severely reduce the effective cross-sectional area of the Bhudni Nullah. Concurrently, the Height Above Nearest Drainage model-based flood exposure assessment quantifies a critical vulnerability, with 11.57 km² (22.14%) classified as “Very High” and “High” flood exposure, concentrated within the built environment. The study provides socio-physical, environmental, and economic indicators for future urban flood modeling and research studies.