ASSESSMENTS OF ARTIFICIAL PULSE TYPE IMPACTS ON BENTHIC ANIMALS IN RIVER USING THE RECOVERY PREDICTION MODEL

Abstract

The population dynamics model describes the annual change of total biomass of benthic animals in river. We developed a recovery model assessing the influence of an artificial pulse type (temporal) impact with two evaluation indexes, i. e. Recovery Rate and Ecological Loss Time. Recovery simulations from a virtual impact were performed in 70 river sites in Tokyo with an assumption that the biomass decreases to 0.08 times just after the impact in each site. This recovery model confirmed the tendency of high resilience of macroinvertebrate as well as the effectiveness of the two indexes for impact assessments in river ecosystem.