The line graph illustrates the rate of high-quality water in UK rivers from 1990 to 2002.
Overall, it stands out from the graph that there was a downward trend in the percentage of river water meeting good quality standards in Wales, while an opposite tendency could be witnessed in the figures for Northern Ireland and Scotland, and the data for England fluctuated over 12 years from 1990. In addition, Wales’ rivers had the highest quality of water at the beginning, but were surpassed by Northern Ireland at the end of the surveyed period.
Moving on to further details, regarding the proportion of fresh river water, the figure for Wales commenced at 95% in 1990, then reamined stable until the next eight years. At the same time, a similar pattern could be seen in the rate of water meeting good quality standards in Northern Ireland, but at a lower starting point of nearly 88% in 1990. Subsequently, this data experienced an increase to 95% in 2000, followed by a slight rise by merely 1% in 2002.
In the same way, the percentage of high-quality river water in Scotland started at 22% in the first surveyed year. At this point, the figure for Scotland speeded up and hit the peak at approximately 58% between 1990 and 2000, and decreased significantly to 40% in the last year of examined period. Meanwhile, the rate of water with good chemical quality in England’s rivers began at 45% before growing and reaching the highest at 69% in 1996. After that, that data declined to its trough at 30% in the next two years, and recovered to 48% in 2002.