農業水利投資の経済効果に関する研究 (第5報) : 宮川用水地域の農家のパターン分析 : 林数量化理論第III類・第IV類による解析 | Economic Studies of Investment in Irrigation (Part 5) : Analysis of Farmer's Pattern in Miyagawa Canal Region : Application of Quantification Theory

In this paper,we have examined the econmic efficiency of public investments in irrigation, through examples of the Miyagawa Canal. In part 1, we consider historical and geographical features of the Miyagawa Canal. The water resources of the Miyagawa River had not been used for irrigation at Miyagawa Canal region in Mie Prefecture, because of complex geography in the area. It took eleven years to construct the Miyagawa Canal from 1955 to 1966, and the dependent channels were completed in 1978. The effects of investments in irrigation have been seen in (1) increase of paddy fields especially in Obata-cho, and (2) increase of induced investment in land-improvement especially in Tamaki-cho, and (3) increase of investments in machines such as tractors, rice-transplanters and combines. But there are undesirable changes of agricultural circumstances for the Miyagawa Canal. Many full-time farmers have become part-time farmers. Consumer's demand for agricultural products have changed, and demands for rice and vegetable have decreased. There are also troublesome problems. First, the Miyagawa Canal was made using techniques of that day, and is not an adequate scale for today. Second, the Miyagawa Canal was made independently, and suitable measures for promotion of agriculture have not been developed. In part 2, we consider the systems of irrigation in the Miyagawa Canal region. The Miyagawa Canal irrigates 5,770 ha of cultivated lands by 8.522m³/s of maximum water. An equipment-ststem of irrigation has been made, but a social system of irrigation has not been made sufficiently. We must make an adequate social system of irrigation to distribute water efficiently in the region. In part 3, we consider the social agricultural system in the Miyagawa Canal region. The example of these systems is Katsuta Agricultural Producer's Cooperation which is a group farming organization in Tamaki-cho. Traditional social systems were changed to new social systems through investment in irrigation. In part 4, we consider effects of investment in irrigation by analysis of questionnaires. The questionnaires were conducted on 665 farmers in the Miyagawa Canal region. 36% of farmers evaluated the Miyagawa Canal very useful for their farming and 71% evaluated it positively. 29% of farmers evaluated it negatively, but the negative evaluations depended on high tax imposition and not on ineffectiveness. The general development of agricultural techniques has been the main reason for agricultural development - increasing production, decreasing labour and improvement in management - in this region. Investment in irrigation has encouraged this development. In part 5, we examine a factor pattern analysis of farmers in Tamaki-cho and Obata-cho where the farmers have benefited notably. The analysis depend on Hayashi's quantification theory. We extracted five factor axis. We named them "farming development axis (first axis)","geographic environment axis (second axis), "economic farm development axis (third axis)","farming direction axis (fourth axis)",and "land improvement axis(fifth axis)".We classified 100 farms into 8 large clusters and into 20 small clusters. In this pattern analysis,"land improvement axis" only appear as the fifth axis. This axis shows the role of land-improvements,which do not develop farming directly, but decrease farm labour and increase non-agricultural income indirectly. Roles of land-improvments to develop the farm management positively are not discovered in any axis. Because there are so many types of farmers, the effects of investment in irrigation are complex. We need to evaluate these effects from point of national economy.