Flood estimation using radar and raingauge data

Flood hydrographs for the Finniss River catchment in Darwin, Australia, were calculated using different approaches to estimate the input rainfalls from the available radar and raingauge data. The rainfall estimation methods were: (1) using raingauge data alone; (2) using kriging of the raingauge data; (3) using radar data alone and (4) using cokriging of both radar and raingauge data. Both probability matching and power law methods were used to estimate rainfall from measured radar reflectivities. The results showed that rainfall estimated by cokriging considerably improved flood estimates, because it optimally combines both the raingauge and radar data to improve the estimate of subcatchment rainfall.