Abstract
The quality of water in Lake Kasumigaura has been deteriorating since 1970's. It is due to pollution discharged from socio-economic activities of the people of the catchment area. But there is no reason to think that we should deteriorate our socio-economic activity level to improve the quality of water. Rather we can remove pollutants by constructing sewerage systems and converting land use system and restructuring industries that discharge less pollution.
In this study, we formulate a model that describes socio-economic activities, the load of pollution due to these and imply instruments in order to reduce pollution without deteriorating the socio-economic activity level. The pollutants measured through this study are nitrogen, phosphorus and COD. These have been strongly affecting the deterioration of water quality in Lake Kasumigaura.
We simulated the model from the year 1996 to 2005. Analysing the result of the simulation, we conclude that we can reduce 12% nitrogen, 20% phosphorus and 18% COD by 2005 from the emission levels of 1995.
