Table 4: Results of the variable fuzzy comprehensive evaluation of seawater quality in the Qingdao dumping area (1985–2003).

YearCODOILDOInorganic nitrogen -PCuPbZnCdVariable fuzzy evaluation model
AverageEvaluation grade

19850.450.0388.731.260.310.494.132.7150.131.30 I
19910.890.0157.8625.96.820.365.79.80.171.33 I
19970.650.07457.7677.314.964.741.2842.50.071.59 II
20001.540.0219.1794.4215.752.980.8613.70.181.14 I
20020.480.0247.9965.76.52.041.4911.160.281.11 I
20030.720.0397.641026.94.302.2541.540.191.64 II