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 1943: Bulgaria spent the longest below LDC, 3 % 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.

3%5%

1943Meanbelow LDC in season

Irrigation season (April–September) 1943
countries	station-days in season	below LDC in season	%	vs. average
Hungary	2,562	0	0%	-2 pp
Croatia	549	0	0%	-1 pp
Bulgaria	1,098	30	3%	-2 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	1943-10-19	1943-11-22	35
Silistra	Bulgaria	1943-11-04	1943-11-25	22
Svishtov	Bulgaria	1943-11-03	1943-11-23	21
Oryahovo	Bulgaria	1943-09-21	1943-10-08	18
Lom	Bulgaria	1943-11-04	1943-11-21	18
Novo Selo	Bulgaria	1943-11-05	1943-11-20	16
Oryahovo	Bulgaria	1943-09-01	1943-09-14	14
Vukovar	Croatia	1943-01-12	1943-01-23	12
Svishtov	Bulgaria	1943-09-26	1943-10-07	12
Ilok	Croatia	1943-11-07	1943-11-17	11

The daily series uses the first reading of each day.