Национален институт по метеорология и хидрология

Хидроложка информация и прогнози




Обща информация   



Наводнение с.Лиляче 05.05.2017 г.

Годишни оценки на:

реките 2015
подземните води 2016


 Месечен бюлетин

•Месечен отток

Подземни води
  • Нива и дебити

  • Мътност
 Снежна покривка

Индекси на засушаване


Проекти и публикации

Дунав-интегрирано управление

About the Climate

Operational hydro-meteorological data

Bulgarian hydro-meteorological observation stations are of two types, with respect to the data transmission:

  • Operational stations transmitting data at real or near real time. The most important 12 river level gauging stations are transmitting daily data to the NIMH regional branches and headquarters. The rest 32 the operational stations are transmitting daily data at weekly intervals. On Wednesday each week NIMH receives daily data for the previous 7 days. Similarly the groundwater observation stations transmit daily or weekly data at weekly or monthly intervals from 160 wells and 25 springs. 200 operational rain gauges are transmitting daily precipitation totals every day, when it is raining. The location of the stations is given on the schemes below.
  • Regime stations are not transmitting data. Different paper forms are prepared by the observers and posted to the NIMH branches at monthly intervals.

Some of the hydrometeorological parameters regularly observed over the Bulgarian territory are relevant for the analysis of the variability of the groundwater recharge. Those are: precipitation, thickness of the snow pack, river and spring discharge, and groundwater tables. General information on the monitoring practices and data pre-processing for those parameters is given below


Discharges are received via rating curve through the observations of the water levels. The levels are generally observed manually with footgauge by observer at 8 o'clock a.m. local time. Because of the high variability of the levels in the small basins, mechanical level recorders are working at approximately half of the stations, using weekly papertapes. Observers of small amount of stations at larger basins are transmitting daily levels via telegram/telephone, while their reporting tables are collected monthly by post. Discharges are measured 8-12 times per year by current meters, or floats in case of dangerous floods. Small springs are measured via volume method. Most of the stations are equipped with measurement bridges. Cross-section profiles are measured one or twice per year, which generally do not include the floodplanes. The frequency of those observations depends on the stability of river bed at the measuring section. Provisional rating curves are maintained for the cross-sections with daily data transmission, while for all stations rating curves and daily mean discharges are validated annually. Certain amount of small river basins having an area of 50-100 km2 are observed above the hydrotechnical structures (dams, derivation channels), while the others with measuring sections located at the lowlands have an area of 200-400 to 1000-5000 km2. Reservoir cascades regulate more than 50% of the surface waters.

Groundwater tables

In most cases groundwater tables are observed using suitable wells constructed for some other purposes, but not used at present (water supply, exploration, etc.). In a few cases shallow waters are observed using dug wells in the villages. The NIMH permanent technical staff via portable instruments once or two times per month measures the levels. In a few cases wells with higher variability of the levels are observed with mechanical level recorders with monthly papertapes. Relevant number of stations are transmitting levels monthly for operational purposes, while the rest of the data are collected annually. Generally all porous and plain karst aquifers are covered by water level observations.