Water Quality Assessment of Shanmei Reservoir by the Comprehensive Water Quality Identification Index

Based on the monitoring data from 2004 to 2006,water quality of Shanmei Reservoir is assessed by comprehensive water quality identification index.The results showed that the order of main pollution factors of Shanmei Reservoir,arranging from highest to lowest pollution degree,is: total nitrogen(TN)total phosphorus(TP) fecal coliform grouppermanganate index(CODMn)dissolved oxygen(DO)NH+4-Nbiology oxygen demand(BOD5).Water quality of Shanmei Reservoir belongs to level Ⅱ as a whole and meets the water function of level Ⅱ.Three pollution factors TN,TP and fecal coliform group,exceed the functional standards,TN is worse than Ⅴ level,TP and fecal coliform group reach level Ⅲ.In conclusion,the eutrophication tendency is evident in Shanmei Reservoir because of the serious deterioration of TN and the increase of TP.