As shown in Table 7, the coefficient for Hydropsychidae is a larger negative value than that for Chironomidae. DeNicola and Stapleton (2002) have proposed that physicalsedimentation of metalprecipitates have a negative impact on benthic macroinvertebrates. Therefore, the physicalsedimentation would be causing a severer damage to the inhabitatation of Hydropsychidae such as Hydrophyche orientalis and Cheumatopsyche brevilineata with a sieve net than Chironomidae which is categorized into ‘‘Burrowers’’ (Merritt and Cummins,1996).