two-dimensional vertical flow analysis model. The lakebed change analysis that the amount of sedimentation of vertical direction was adopted more than that result is being enforced, and examined comparison and analysis with distribution area and sedimentation point of the fine sediment about Lake Utonai. In this result, confirmed local application in Lake Utonai, and the simulation model that developed in this study clarified a sediment tendency.

The area of this study, Lake Utonai, is in eastern Tomakomai, Hokkaido, Japan. In recent years, the lake has been experiencing the ecological eutrophication resulted from nutrient salts and fine sediments from the rivers, which will damage the ecosystem. The lake water is affected by sea-land wind from costal regions, and by groundwater flow, due to the lake's shallow depth. This study proposed a water quality model and a water flow model for the shallow lake, considering effects of groundwater flow and sea-land wind.

No abstract

In recent years, the wetland area, including Lake Utonai has been experiencing eutrophication , which is damaging its ecosystem. The cause of eutrophication is an influx of water from rivers that have been contaminated by large amounts of nutrient salt and fine sandy soil transported by an influx of water . This report will propose a water dispersion model, considering the effects of groundwater and water flow-driven by wind. The model is designed to help ascertain the exact cause of eutrophication as well as to carry out an impact assessment on these ecological problems . The proposed model is a Water Quality Dispersion Model that has been applied to a Lake Flow Model, which is made up of a Groundwater Flow Model and a Boussinesq Model, combined with Kriging . As well, it is revealed that both the inflow and outflow of groundwater have a great impact on the flow of Lake Utonai regarding the accuracy analysis of the water-quality analysis model. This result implies that it is essential to consider the inflow and outflow of groundwater as a calculation condition to ensure greater accuracy when analyzing the water flow of shallow lakes , which are connected to ground water.