Abstract
To evaluate economically multi-functional roles of the Yasugawa agricultural water by a contingent valuation method (CVM), mean values per household of willingness to pay (WTP) were estimated from the Turnbull scheme and with the Weibull distribution, and were 4, 352 yen and 4, 096 yen, respectively. Each functional role was evaluated economically using the combined index of its usefulness and importance, and functions of flood control, ecological preservation and water quality preservation were evaluated highly. The values of WTP allotted to their functions were 1, 262 yen, 827 yen and 1, 001 yen, respectively. From the analysis of collected questionnaires, was obtained the result that the practical function of flood control was evaluated highly at present, but the functional improvement of water quality reservation was expected in future. Many difficulties are involved in the distribution and the collection of questionnaires. Therefore, a linear relationship between the mean value of WTP estimated from the Turnbull scheme and the rate of non-farm household was presented to reduce those difficulties. Data investigated and obtained in 4 agricultural irrigation districts were used. The relationship could be applied to other agricultural irrigation districts adjacent to these 4 ones to estimate the rough value of WTP.
