Lake comparative study and its application to the management of the drainage basin.

To propose the software and hardware systems for promoting environmentally sound management of lake and its drainage basin, the first step was made to pointing out the similarities and differences among the four East-Asian lakes; L. Kasumigaura (Japan), L. Laguna (Philippines), L. Songkhla (Thailand), and L. Dianchi (China). They are seriously expected to play a central part in the supply of water resources, but now confronted with the shortage of water quantity and the deterioration in water quality. Some comparisons from the many different kinds of viewpoints for example topographical, meteorological, socio-economic environments, characteristics of ecosystems, etc. indicated the vulnerability of water resources in the lakes of such type. A simple calculation with the aid of the notion of human carrying capacity also suggested that larger forest area would be necessary in the catchment area for satisfying the demand for drinking water and that for maintaining the good condition of lake water quality.