Rainfall Event Analysis for Urban Flooding Study Using Radar Rainfall Data.

Volume 17 , Issue 3 , September 2015 , Pages 137-148

Authors

¹ Directorate of Groundwater-Sulaimani, Kurdistan Region, Iraq

Urban flooding is one of the most serious challenges facing urban areas and causes

destruction of properties and major problems for people living in urban areas. It

occurs in an urban area when intense convective rainfall happens that is higher than

the capacity of the urban drainage system. Rainfall data can be recorded by radar and

by rain gauge. It is essential for urban flooding studies to have access to high quality

rainfall data in attempting to reduce and tackle this challenge. The main aim of this

paper is to test the quality of radar data by means of rainfall event analysis. Radar

data obtained from Yorkshire Water were analysed and compared to rain gauge data

during selected rainfall events in a study area located in North Yorkshire in the UK.

Rainfall intensity curves within 5 minute and one-hour intervals, cumulative rainfall

depth curves and normalised bias were used as standard methods for comparison

between radar and rain gauge data during the selected rainfall events. Available data

were collected for June, July, and October 2008 and were recorded from Blackhill,

Harrogate North, and Helmsley rain gauges, and radar data for these same locations

were also collected. The results of this thesis show that certain errors might have an

impact on radar data in terms of quality. Some such errors caused overestimation of

radar rainfall data, such as anomalous propagation error and error related to

thunderstorm. However, other errors, such as attenuation, caused underestimation in

radar rainfall data.

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