Agricultural Water Management as a Safety Net for the Domestic Water Supply during Abnormal Dry Spells: An Analysis on the Behavioral Science in Water Management

摘要

Water is and has always been indispensable for agriculture. Water is also indispensable for people living in modern cities who are not aware of this fact in normal times. They only become realizing the value of water when a severe dry spell results in certain hours restriction of water supply in a day and further suspension of water supply for days. Similarly in the case of earthquakes, typhoons, floods and other disasters, there is no guaranteed protection against suffering from damage of water shortage even if no matter how well prepared you may be. And like in the case of these other threats, it is impossible to predict when, where, and to what extent you may be affected. It would therefore seem that we can only take measures such as constructing disaster prevention infrastructures and arranging insurance systems to mitigate damages when calamity does strike.rnBut in the case of water shortage, even if a dry spell is abnormally severe, peoplerncan take an efficient emergency measure on the basis of mutual trust and reciprocity. Water users can alleviate overall losses by taking collective actions, as the dry spell progresses, leveling the degree of damage to be suffered by each individual. Even during the hardest nationwide dry spell on record in the 20th Century, which struck in 1994, we observed in many part of Japan the well-ordered temporary water transfer from agricultural to domestic users with no disturbance of so-called dilemma in collective action.rnThe risk of dry spells is growing higher recently in Japan's cities. Everyone clamors for the scarce water during abnormal dry spells. This paper presents case studies of how, during such dry spells, farmers in the vicinity of cities have voluntarily reduced water use and temporarily transferred the scarce water to the domestic water supply. It then examines the behavioral science involved. As background, the author observes that, in humid regions like monsoon Asia including Japan, agricultural water usersrnface a paradox in the risk of dry spells because agriculture in humid regions expects direct rainfall to farm fields more than that in arid regions, for which reason they are doomed to experience repeatedly a situation of tightened supply and demand for water.rnThe author goes on to examine, in light of game theory as used in economics, why farmers in the vicinity of cities have come to expend such extraordinary effort on helping urban residents out of their distress by transferring water to them during abnormal dry spells; particular consideration is given to the significance of social capital as one factor underpinning this form of collective action.rnIt is concluded that the organizational capabilities that, through farmers' intelligence, experience and achievements in agricultural water management run by their collective actions, they have built up over the years in the course of the repeated experience in water disputes and reconciliations have functioned as a safety net for the domestic water supply during abnormal dry spells.