Validation of Doppler radar in estimating intensive daily rainfall in Urmia Lake catchment

The aim of this research is to investigate the accuracy of the heavy rainfall data (rainfalls of 25 mm or more) of Tabriz weather radar in a period of 8 years (2014-2021) and compare them with synoptic station data in basin. To compare and evaluate between meteorological stations and radar data, statistics such as, correlation coefficient (R) and root mean square error (RMSE) were used. The comparison of the maps obtained from Doppler radar and rain gauge stations showed that the spatial distribution of precipitation from the two databases was not the same and the low and high rainfall areas did not match each other, so that the correlation coefficient between the radar and observed precipitation was 0.25. Also, the results of Kolmogorov-Smirnov test showed that considering that the obtained p-value (0.000) is smaller than the error value of the test (0.05), then the difference between radar precipitation data and ground observations is significant. In fact, the rainfall values recorded in the ground and radar stations do not provide a single result, and none of the statistical populations have a uniform distribution, therefore the radar rainfall data cannot be used instead of the rainfall data of the stations.