A radar data quality control scheme used in hydrology

Rainfall-runoff models become increasingly important as efficient instrument for ecological and economic management of rivers. Rainfall is the most relevant information and the most uncertain one to determine for rainfall-runoff models. For rain gauge data the problem is the spatial representativity of the information, whereas for radar data the problem is the volumetric sensitive to several error sources. Within a project of rainfall-runoff simulation based on either raingauge or combined radar and raingauge information, the Landesumweltamt (State Environmental Agency) of North Rhine-Westphalia supported the development of a radar data quality control scheme. Rainfall data quality is the key feature for reliable results from a rainfall-runoff model. The methodology was developed on one year of continuous 5-minute radar data (PF-product of German Weather Service). Radar data was checked by daily statistics, overview statistics, visual inspection, time series analysis, comparison to rain gauge data, adjustment to raingauge data. This quality control concept proved to be efficient for the hydrological data use.