抄録
Water resources in the lower Mekong river basin as an international river, was evaluated using a conceptual analysis method based on water balance. GIS prepareddata sets of elevation, land use and slope data to understand the ratio of.land use in the area. A conceptual area was introduced for easy understanding. It wascovered with only three categories, which are forest, urban and cultivated regions. Water balance equation involving rainfall, evapotranspiration, infiltration, storage and runoff was calculated for water demand for people. As the results, the number of drought months will increase as cultivated area will increase. Especially, serious seasons are dry season and the rice-planting season. It was alsounderstood that population in the area would be limited by water supply for people. Japanese climate condition was also used to compare with the Mekong region. Although this model is simple, the obtained results show us the possibility of the future problems.
