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

近年来，人们对灌溉池塘的保护和改良考虑的问题也越来越多。由于堤防结构的特点，需要定期对其进行加固处理。因此，我们认为有必要在最大限度上共同改善灌水池及其周围环境，分别改善各个池塘。既然如此，以前就需要同时掌握每个灌溉池塘需要进行什么样的维护，以及它的老化程度是什么。本研究的目的是明确考虑周边环境的灌溉池塘保护与改造的规划方法。本报告对灌溉池塘的分组方法和测量方法进行了研究，以确定灌溉池塘的老化程度。第一章介绍了将每个池塘分成几个组的方法，并结合维修的方式在香川县的应用。我们只使用已公布的数据来预测这种方法。通过像县这样的大范围区域，可以得到有用的结果。第二章讨论了同样的方法。然而，我们将其应用于香川县桑格瓦镇，通过主成分分析和聚类分析进行了分组。第三章对三川镇230个灌溉池的调查方法进行了研究。讨论了灌溉池塘调查项目、实际情况调查、层次分析法问卷分析、评价项目权重值的确定、池塘老化程度的估算等问题。显然，灌溉池塘可以根据老化程度进行排列。

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.