Bridging the skies and space: A comparative analysis of satellite and aerial data for urban waterlogging assessment – A case study of  Sector 28 corridor between Dwarka and Khaira, New Delhi, India

Urban waterlogging is a serious problem in fast urbanizing regions, exacerbated by climatic variations and poor drainage facilities. This paper situates Unmanned Aerial Vehicle (UAV) and Light Detection and Ranging (LiDAR) remote sensing methods as viable tools for assessing waterlogging in the Dwarka-Khaira corridor, New Delhi, India. Conventional terrestrial field monitoring is restricted by resource constraints and scale, whereas high-resolution aerial methods provide detailed hydrological information. UAV and LiDAR deliver excellent spatial resolution and vertical accuracy necessary for the identification of microtopographic features critical for detecting hydrological restrictions. The RMSE of the UAV-derived DEMs was highly reduced to 4.6 m through post processing, with an increased accuracy of 83.66% and was conducive for a good performance in hydrological modeling. UAV data, which had ground sample distance less than 5 cm, facilitated urban feature classification with an accuracy of 98%) and helped to mitigate spectral confusion and misclassifi cation observed from Landsat (30 m) data. High-resolution aerial data therefore minimized false-positives and enhanced network extraction quality as compared to their satellite based counterparts. But while satellite imagery is not well matched for development level analysis, it continues to offer useful potential for regional assessment of vulnerability. Combining data from both sources is consistent with evidence from similar research, in support of models based on Sustainable Development Goal resilience targets. The application of these enhanced methods ed to a 30-40% decrease in identified waterlogged areas. So, the study offers a scientific basis for urban water management policies and planning.