Evaluation model of policy scenarios for basin-wide water resources and quality management in the Tone river, Japan

The objective of this study is to evaluate the conceptual scenarios of vari ous water resources and quality management on the same level of policy deci sions for optimizing river basin management. First, the water and pollutant s balance model in the upper reaches of the Tone River is proposed. This mo del has the following characteristics: (1) Water quantity and quality at va rious target points of the rivers are estimated simultaneously, with a stat istical evaluation for the uncertainty of hydrological events; (2) The mana gement scenarios include selection of water savings in domestic use, reserv oir construction, the expansion of sewerage coverage and so on. Several int eresting results supporting policy making are obtained as follows: (1) Fift een percent reduction in domestic use is sufficient as a substitute for new reservoir; (2) the expansion of sewage coverage in the upper reaches has l arge effects on reduction of BOD and GOD, but the nutrient removal process should be introduced in sewage treatment plants for reduction of TN and TP. (C) 1998 IAWQ. Published by Elsevier Science Ltd. All rights reserved.