Author(s): Katsuaki Komai; Keisuke Nakayama; Yusuke Fukuoka; Mamoru Kawai; Shinya Nakashita; Yoshiteru Ichikawa
Linked Author(s): Katsuaki Komai
Keywords: Wetland; Nutrient transport; Distributed hydrological model; Fine suspended sediment
Abstract: Impact of rainfall event on the discharge of fine suspended sediment and nutrient in stream water in Kushiro wetland and its surrounded basin were investigated by field observation on water qualities and runoff analysis based on distributed hydrological model. Rainfall event has large impact on nutrient transport according to the results of total nitrogen, total phosphorous, and fine suspended sediment concentration being several to several score times larger in rainfall event than in ordinary discharge period. The numerical results are in good agreement with observation in terms of river discharge and suspended solid concentration. The production rate of suspended solid likely depends on land use and topography in local small basin. According to the observed data and numerical results, modeling of the behavior of fine suspended sediment with rich nutrient source is likely estimated to reproduce most of nutrient transport with hydrological numerical simulation. Primary production in lake and wetland is probably related to phosphorus supplying in rainfall event. Primary production due to eutrophication in lake and reed community likely enriches organic substances and carbon in stream water.
Year: 2014