Statistics

Statistics by country and year

Yearly summaries computed from the daily readings of every station: how many station-days were spent below the low-water level (LDC) or above the high-water level (HDC) — as a count and as a share of the station-days with thresholds. Useful for agriculture (irrigation seasons with low water) and navigation (days with restricted draught).

Agriculture: station-days below LDC mark the low-water periods when irrigation intakes and water availability are under pressure.
Navigation: days below LDC mean draught restrictions on that sector; days above HDC mean suspended traffic.

Daily data from 1879 to 6 November 2026

Download this tab’s data (CSV)

LDC: Low-water mark. The river stays above it on 94 of 100 ice-free days; below it, ships cannot sail fully loaded.
HDC: High-water mark. The river exceeds it on 1 day in 100; above it, navigation can be suspended.
Station-days: One station-day is one station measured for one day: 13 stations over 10 days make 130 station-days. It shows how widely and how long something lasted.

Irrigation season 1946: Bulgaria spent the longest below LDC, 5 % of days

Irrigation season (April–September)

Station-days below LDC in the irrigation season, by country and year, against the average of the other years; the longest uninterrupted spells below LDC.

5%5%

1946Meanbelow LDC in season

Irrigation season (April–September) 1946
countries	station-days in season	below LDC in season	%	vs. average
Hungary	2,562	0	0%	-2 pp
Croatia	366	0	0%	-1 pp
Bulgaria	1,098	50	5%	0 pp

Longest spells below LDC

Uninterrupted periods of at least 5 days below LDC, by station.

Longest spells below LDC
Station	countries	From	To	days
Oryahovo	Bulgaria	1946-09-20	1946-11-09	51
Silistra	Bulgaria	1946-09-23	1946-11-11	50
Svishtov	Bulgaria	1946-09-24	1946-11-10	48
Novo Selo	Bulgaria	1946-09-26	1946-11-05	41
Lom	Bulgaria	1946-09-27	1946-11-06	41
Vukovar	Croatia	1946-12-25	1947-01-18	25
Ilok	Croatia	1946-12-27	1947-01-10	15
Ruse	Bulgaria	1946-10-13	1946-10-20	8
Oryahovo	Bulgaria	1946-08-25	1946-08-31	7
Silistra	Bulgaria	1946-08-28	1946-09-03	7

The daily series uses the first reading of each day.