The line graph compares the proportion of good chemical quality in UK rivers from 1990 to 2002 across four countries: Wales, Scotland, Northern Ireland, and England.
Overall, it is noticeable that figures for Northern Ireland experienced an upward trend, while Wales saw a downward trend over the period. Meanwhile, England and Scotland experienced fluctuations over the period.
The percentage of good chemical quality in Scottish rivers started at about 22% in 1990, rose steadily to reach a peak of nearly 60% in 2000, and then decreased to 40% in 2002. The figures for England fluctuated wildly between 45% and 50% by the end of the period.
In Wales, the percentage of good chemical quality remained stable at around 95% for the next 8 years and decreased to 80% between 1998 and 2002. However, Northern Ireland also remained stable at around 87% from 1990 to 1998 and increased by about 7% between 1998 and 2000.
