We have a knowledge of the collection of hydrographic data characterizing the territory of Hungary dating back about two millennia. Most of the data of the older ages existed in a destroyed, ordered, systematic form only from the first half of the last century, and from the second half the hydrographic data were collected in an organized, centrally controlled manner. The Hydrographic Department of the Ministry of Public Works and Transport, established in 1886, was the first organization to collect, measure, evaluate, and forecast floods in the country. This was the first organized hydrographic service in the Carpathian Basin. The content and versatility of Hungarian hydrographic data collection preceded many similar foreigners.
As a result of developments in recent years, the vast majority of perceived and measured data are processed on a computer. In this way, the data and information are easily accessible at any time to the widest camp of interested parties. Both the Water Directorate and the Data Controller are responsible for the reliability of the data produced in their own hydrographic network.
The data collected by the hydrography are entered into a single hydrographic database. Within this, the Hydrology Module manages the data of the rapid reporting and automatic, remote signalling stations of the hydrographic network, which is essential for the performance of the water damage prevention activity in the preparation of the decision. The Hungarian Hydrological Database (MAHAB) is the largest database of the water service, containing quantitative hydrological time series, with the largest size and content. Three-level data processing was implemented. Data from the original detected-measured, recorded, and control measurements represent the first level. These data are recorded in the same way as the original measurement without any changes. Based on algorithms and correlations, derived data sets are made on the one hand, and on the other hand, the users of the branch perform primary data processing, which means the second level, these are the calculated data. The classified and processed data sets are then placed in the public hydrological time series. This is the third level.
Telemetry stations are stations with a registrar that, in addition to the local registration of operational data, also allow the transmission of the registered data to a telemetry centre set up for this purpose. Telemetry systems use state-of-the-art sensing, data acquisition and communication tools. Data arriving at the system centre can be graphically and tabularly displayed, processed and transmitted to other processing systems.
Data of surface stations
From the water level data measured at the surface stations, the remotely measured data are available on the website www.vizugy.hu.
Data of near-surface waters
As a result of the investment made during recent years the remote surveying of the groundwater wells are increasing year by year. Data on these wells are entered directly into the database.
Data of hydrometeorological stations
As a result of the investment implemented jointly with the National Meteorological Service, 141 hydrometeorological stations were automated and remotely surveyed. The data of these stations are used in the forecasts prepared by the OMSZ.