Kushiro wetland is located at the downstream of Kushiro river, which is classified as the first class river and takes water from Kussyaro-lake as the source. Kushiro river is known as slow and meandering stream, and it brings in abundant mineral and nutrition from whole watershed and carries those to downstream. The river flows into the Kushiro wetland, and eventually reaches to the Kushiro-shi to support their city life.
Kushiro wetland has several function related to the surface water. For example, Kushiro river is known as the one to have small fluctuation in waterlevel, and this is due to the function of wetland as a balancing reservoir. It also functions as filtration to stabilize excessive BOD （See detail about BOD) and nutritions （See detail about nutrition） on the soil and/or vegetation of wetland. These functions are so much beneficial in terms of water quality at downstream of wetland, but at the same time it means to accumulate enviornmental load onto the Kushiro wetland.
Fundamental Info.
Nature of Wetland
Topic 1
