The line graph illustrates the percentage of water in four different UK regions (Wales, Northern Ireland, England, and Scotland) that was classified as having good chemical quality over a twelve-year period from 1990 to 2002.
Overall, Wales and Northern Ireland consistently exhibited higher percentages of good chemical quality compared to their counterparts, with significant fluctuations evident in the data for England and Scotland.
With regard to the two leading nations, Wales commenced with an impressive 95% of good chemical quality in 1990, which incrementally increased to a remarkable 100% by 2000 before slightly dropping to 95% at the end of the period. Northern Ireland experienced an upward trajectory, with its purity reaching 99% by 2000 after several years of stagnation, and then slightly falling to 96% by 2002, having surpassed Wales in 1999.
Regarding regions with major fluctuations, in 1990, Scotland’s rivers were of the lowest quality in terms of chemical preposition, with only 23% of river water there up to par, less than half of England’s 45%. Subsequently, the latter’s purity fluctuated moderately until it peaked at 70% in 1996. This upward trend, however, was followed by a steep decline to around 30% in 1998 before having a significant recovery to 50% by 2002. Similarly, the percentage of clean water in Scotland rose steadily, achieving its zenith of 60% in 2000 before declining to 40% over the final two years.