Method of Planning for Irrigation Pond Conservation and Improvemet Considering Surrounding Areas Environment

近年来，灌溉池塘保护与改善应考虑的问题日趋多样化。由于老化堤防的结构特点，需要定期对其进行改造。因此，我们认为有必要在每个塘单独改善的同时，对灌溉塘及其周边环境进行共同改善。既然如此，那么在此之前就有必要掌握每个灌溉池需要进行怎样的维护，同时它的退役程度是怎样的。本研究的目的在于阐明考虑周边环境的灌溉池保护与改善规划方法。本文对灌溉池的分组方法和测量方法进行了研究，以确定灌溉池的老化程度。第一章论述了各池分组的方法，以及在香川县应用的养护方法。我们只使用公开的数据来划分方法。通过像县这样广阔的区域，可以得到有用的结果。第二章讨论了同样的方法。本文以香川县三川镇为研究对象，采用主成分分析和聚类分析方法进行分组。第三章论述了以三川镇为研究对象的230个灌溉池塘的测量方法。讨论了灌溉池塘的调查项目，对实际情况进行调查，采用层次分析法进行问卷分析，确定了评价项目的权重值，对灌溉池塘的老化程度进行了估计。由此可见，灌溉池可按退耕程度进行梯级排列。

Recently, it comes to diversify that the matters we should consider on the conservation and improvement of irrigation pond. It is periodically necessary to improve superannuated dike because of stuructual feature. Therefore, we consider it necessary to improve irrigation pond and its surrounding areas environment together at the oppotunity to improve each pond seperately. Since that is so, it is previously necessary to grasp what kind of maintenance is required for each irrigation pond and what is superannuated degree of it at the same time. The aim of this study is to clarify the method of planning for irrigation pond conservation and improvement considering surrounding areas environment. This report deals with studies on the grouping method of irrigation pond and surveying method in order to decide superannuated degree of it.The first chapter deals with the method which making each pond into some groups in conection with the way of maintenance to applying in Kagawa prefecture. We divise the method using publised data only. Useful results could be obtained through the wide area like prefecture.The second chapter discusses the same method. However, we applied it in Sangawa town of Kagawa prefecture as the grouping method by principal component analysis and cluster analysis. We could presented the useful method at the level of local goverment as townsThe third chapter deals with the surveying method about 230 irrigation ponds which became the object in Sangawa town. We discuss surveying items of irrigation pond, investigation of the actual conditions, analysis through questionnaire by AHP method, decision of the weight value about evaluated items, and estimation of superannuated degree of the ponds. It becomes clear that the irrigation pond can be arranged in ranks according to the superannuated degree.