Towards a roadmap for use of radar rainfall data in urban drainage

Radar rainfall has received growing attention in the urban drainage community since its first appearance on an Urban Storm Drainage Conference in 1984. Still, operational applications of radar rainfall in urban hydrology is limited. The following aspects have to be considered for radar rainfall data use specifically in urban hydrology: the type of the radar, the application requirements on the radar data, the achievable radar data quality, forecast possibilities and limits. Quantitative applications of weather radar to urban hydrology are becoming more mature with better understanding of limitations and achievable accuracy. Research in the US and Europe has led to operational applications of radar to site-specific forecasting of floods and management of sewer overflow during wet weather. The uncertainties and methods for obtaining accurate rainfall measurements at high resolution and with areal extents consistent with urban catchments is a major focus of this article. Evaluation and improvement of quantitative precipitation measurements are described in this overview with specific research and operational examples of radar use in urban hydrology.