Data entry was the most time consuming task of the NDBHMI project. Many checks were applied to the data themselves as well as to the procedures used during all phases (digitization, data conversion etc.) of the 3-year period of this project task, due to the requirement for correct and reliable data in the database.
About 450,000,000 recordings from different gauging instruments were either digitized or typed in order to be imported in the database. These data were originally stored in handwritten data forms, recording instrument tapes, ascii files and other digital forms of storage. They cover the whole country and represent almost the total of the available data in Greece. Various globally accepted methodologies were used for the checks and the conversion of data in a consistent and compatible format mostly depending on the variable and storage type. Following the conversion in electronic form, data were imported in the database using customized data importing applications.