Abstract
Preferences or perceptions of ordinary citizens on three kinds of nonconventional water resources including rainwater, permissible groundwater exuding to underground railway stations and tunnels and reclaimed wastewater were investigated by use of the Internet survey method. The survey results were analysed with analytical hierar chal process (AHP) and willingness to pay (WTP). Weight vectors of natural environment and people's lives were found larger than other three first order evaluation conditions, society, economics and technology. The order of the weight vector values for the three water resources were rainwater, reclaimed wastewater and permissible groundwater. That for the five water usages were agricultural and horticulture water, water storage in preparation for disaster, toilet flushing water, environment water and sprinkler water for washing road and cooling atmosphere temperature. The difference between toilet flushing water and environment water was not significant by 5% significance. The analyzed data showed that differences between the weight vector values of the alternatives (water resources and their usages) became small by increasing the number of the evaluation conditions, which would be a topic to be resolved for AHP application to actual public projects. For water resources, WTP with public budgets was Japanese Yen (JY) 53,100-55,100 person-1 year-1, and WTP with private finances was JY 19,100-20,800 person-1 year-1. For water usages, public WTP was JY 20,400-47,200 person-1 year-1 and private WTP was JY 8,400-16,000 person-1 year-1. The orders of WTP values were similar to the orders of the weight vector values for both water resources and their usages obtained by the AHP analysis. Effective dissemination subjects and objects of the nonconventional water resources and their usages were extracted by the analysis for attributes including sex, age, living area, occupation and education.
