Impacts, challenges, and solutions of urbanization on urban stormwater runoff

Abstract

The analysis of urbanization and climate change impacts on stormwater runoff demonstrates that the rapid expansion of impervious surfaces, the loss of natural retention areas, and aging, capacity-deficient drainage networks are the primary drivers of increased peak flows and heightened flood risk. The study integrates hydrometeorological datasets, remote-sensing observations, land-use change analysis, and assessments of drainage system performance to clarify how urbanization alters runoff dynamics and creates systemic bottlenecks in stormwater management. Results indicate that surface runoff in highly urbanized areas can increase by a factor of 4–5 compared with natural conditions, with flood peaks occurring more rapidly and with greater intensity. Moreover, extreme rainfall events during 2024–2025 repeatedly exceeded the design thresholds of existing drainage systems, triggering widespread and severe flooding in Hanoi, Ho Chi Minh City, the Central coastal region, and even midland urban centers. High-density development, insufficient permeable and retention space, and fragmented urban planning frameworks further exacerbate socio-economic vulnerabilities and environmental degradation. The study recommends a suite of measures, including integrated urban–hydrological planning, climate-adaptive drainage upgrades, expansion of nature-based green infrastructure, enhanced early-warning and smart-operation systems, and strengthened community-based management to mitigate peak runoff, increase urban resilience, and support sustainable urban development.