Modeling Multi-Objective, Interbasin, Surface Water Development System with Supplementary Use of Reclamation System

Abstract

This paper centers on the multi-objective, interbasin, surface water development system, whereby, if necessary, the conjunctive use of reclamation system is assumed to be available. The major objectives of the paper include (i) analysis of the quality of industrial waters blended with renovated waters ; (ii) identification of the relation between the blended water demand and its blending ratio and (iii) modeling and analysis of the coordinated attainments of multiple goals involved in the stated system. A case study is conducted at the interbasin system of the southern part of Hyogo Prefecture and some informative results obtained point to the need of this kind of alternative water utilization systems. The major findings of the study include : (1) The reclamation system is required to be implemented on a certain scale to supplement the industrial water supply. (2) In cases where the permitted-levels of the collection goals related to each river basin are set to be relatively higher, the total amounts of water supply that must be covered by the reclamation systems should be allocated to the system of each basin roughly in proportion to the amounts of its industrial water demand. (3) The increased attainments of the amounts of collection, and in consequence, the increased attainments of the improvement in the blended water quality are achievable only at the sacrifice of economic efficiency. (4) The attainments of the goals are seen to be well-balanced and not biased to any of them, chiefly owing to the L-type utility function underlying the model.