Biochemical oxygen demand and ammonium in European Rivers

Two time series are shown – a longer time series representing fewer water bodies and a shorter time series representing more water bodies.

Left chart:
Biochemical oxygen demand (BOD) in rivers: The number of river monitoring sites included per country is given in parenthesis:
1992-2021: Albania (4), Austria (1), Belgium (26), Bulgaria (56), Czechia (22), Estonia (33), Finland (5), Ireland (3), Latvia (13), Lithuania (22), North Macedonia (4), Slovakia (8), Slovenia (8), Spain (78), Sweden (1).
2000-2021: Albania (5), Austria (1), Belgium (36), Bulgaria (73), Croatia (23), Cyprus (4), Czechia (22), Estonia (35), Finland (5), Ireland (14), Italy (44), Latvia (16), Lithuania (22), North Macedonia (8), Poland (90), Romania (88), Serbia (33), Slovakia (8), Slovenia (10), Spain (177), Sweden (1).

Right chart:
Ammonium in rivers: The number of reported river monitoring sites per country is given in parenthesis:
1992-2021: Albania (4), Austria (1), Belgium (20), Bulgaria (38), Estonia (35), Finland (59), Germany (119), Ireland (4), Latvia (12), Lithuania (22), North Macedonia (5), Norway (26), Slovenia (7), Spain (22), Sweden (110).
2000-2021: Albania (8), Austria (1), Belgium (23), Bulgaria (56), Croatia (23), Estonia (37), Finland (68), Germany (122), Iceland (1), Ireland (28), Italy (25), Latvia (15), Lithuania (22), North Macedonia (17), Norway (26), Poland (4), Romania (89), Serbia (33), Slovenia (8), Spain (55), Sweden (112).