The line graph illustrates the proportion of good river water quality in four different countries namely, Wales, Nothern Ireland, England and Scotland from 1990 to 2002.
Overall, it is clear that there was an increase in the percentage of quality of river water in three countries while it witnessed a slight decline in Wales. However, Wales had the highest figures untill 1999
In detail , The quality of river water in Wales throughout the period starting from around 95% in 1990 and dropped to 80% in 2002. Meanwhile, the opposite trend was observed in the rivers of the North Ireland, where good chemical quality started at about 85% and increased to more than 90% in 2002.
Furthermore, England’s river that was having good chemical quality increased gradually from under 45% to around 70% between 1990 and 1996 , after six years the qualities declined to just below 50%. In Scotland, more than 20% of good qualities were found in rivers, which increased to 60% in 2000, but after two years quality declined by 20%.