Nagahisa Hirayama

Revising the existing Performance Indicator system for small water supply utilities in Japan

97.5% of the water utilities in Japan serve less than 50,000 customers, and are called small water utilities. The Performance Indicator system in Japan, used to evaluate the performance of various aspects of the supply system, currently has 137 items, which are too many in number for the small utilities to adopt because of resource and financial constraints. The objective of this study is to, thus, revise the existing PI system to arrive at a reduced, relevant and practical structure that provides enough information to rationally evaluate small water supply systems in Japan. Principal Component Analysis was used to reduce the dimensionality of the original data. The results suggest that only nine components, consisting of 33 items (called 9-cPIS), are sufficient for evaluating the small water utilities. The effectiveness of the 9-cPIS in benchmarking, evaluating business models, and the planning and management of the water utilities has been discussed further.

Establishment of disaster debris management based on quantitative estimation using natural hazard maps

In this study, an estimation procedure was established to assess the amount of debris resulting from earthquake and flood disasters. Per unit generation of earthquake disaster debris was examined on the basis of observed debris discharge from the 1995 Great Hanshin Awaji Earthquake and the 2004 Niigata Chuetsu Earthquake. In addition, the per unit generation of disaster debris from flood damage above floor level was estimated at 4.6 t/household. It was shown that this procedure would allow the amount of debris to be estimated in order that disaster management and operation systems could be established for not only emergency response in the aftermath, but also pre-disaster planning. In a case study, the amount of disaster debris from earthquake and catastrophic flood disasters in the Tokyo Metropolitan Area was estimated according to hazard maps. It is concluded that it is important, from the viewpoint of the security of sanitary systems in the damaged district, that disaster debris management systems including wide-ranging cooperative measures should be established.

Development of evaluation model for consumers' satisfaction of water supply service

The objective of this study was to develop a model to evaluate and quantify customers’ satisfaction (CS) with water supply service using statistical analyses, and develop a relationship between the CS and selected performance indicators of supply service systems to understand how the performance of the system is affected by changes in CS. This study used an Internet based questionnaire survey to evaluate the CS, and was conducted in the Kansai region of Japan in December 2011. A five point Likert scale was used to evaluate the responses received for the questionnaire items based on a literature review for an insight into what consumers in Japan really want or expect from their water utilities. Quantification of the CS was done by factor analysis which suggested that ‘Trust in water utility’ and ‘Good quality water’ are the main variables of the CS factor, which are both intrinsically related to water quality. In addition, ‘Price of water’ and ‘Equity of distribution’ are among the other variables that have some influence on the customers’ satisfaction factor. In order to understand the impact of CS on different components of the supply system, a regression relationship was developed between the CS and selected performance indicators used to evaluate the system performance.

Evaluation of watershed water quality risk reduction after earthquake disasters

In this study, a procedure is established for evaluating the watershed water quality risk reduction after earthquake disasters. Using the method of scenario planning, the risk scenario of watershed water quality in the aftermath was developed as a model of decision tree that can describe the uncertainty events, decision-making and emergency response. Using the watershed water quality risk scenario and the watershed flow model based on box model with mass balance, a model for evaluating the watershed water quality risk was developed. Numerical simulation analysis for estimating the watershed water quality risk in Lake Biwa and Yodo River basin after an earthquake disaster was conducted. Furthermore, the effectiveness of countermeasures against watershed water quality risk was estimated. As a result, it was pointed out that the comprehensive countermeasures with cooperation of stakeholders in the watershed water quality, including information sharing, would reduce considerable watershed water quality risk. Consequently, it was indicated that implementation of the cooperative countermeasures for preservation of watershed water quality for water supply with stakeholders related to watershed water quality would reduce watershed water quality risk in the aftermath effectively.

Implementation of intelligence of flood disaster debris discharge for emergency response

In this study, a procedure is established for estimating and assessing the amount of flooding debris following a flood disaster. The per unit generation of flood disaster debris, which takes into account criteria such as the extent of housing damage as a function of inundation duration time, is examined. It is shown that this estimation procedure would make it possible to estimate debris discharge, which is helpful for the establishment of disaster management systems not just as emergency response measures, but also for pre-disaster planning. The proposed Relative Quantity of disaster Debris (ReQD) provides insight that makes it possible to ascertain the emergency response capability of local governments. The ReQDs of selected flood disasters in Japan are examined. For the establishment of effective emergency response systems, it is important to evaluate information on both the ReQD and the quantity of flood debris. From these facts, it is concluded that the implementation of ReQD can help in the establishment of effective support systems with a wide range of cooperative measures for districts in the process of flood recovery and reconstruction, as well as in the emergency response stage.

GOAL PERIOD OF EMERGENCY RESTORATION OF WATER SUPPLY AFTER EARTHQUAKE FROM THE VIEWPOINT OF CITIZEN'S COMPLAINT BY TELEPHONE

復旧時の応急給水活動に着目して震災時応急給水のモデルの構築を行い、復旧期間における応急給水に関する市民の生活状況を推定した。その上で、応急給水量格差や復旧日数などの市民の応急給水状況に関、する認知要素について主成分分析を行うことで、震災時水道復旧過程での市民からの電話データを説明することができた。復旧に時間を要するほど、応急給水過程での公平性が小さくなり、市民は不公平を感じるようになると推定できた。震災時応急復旧過程での電話データからみたとき、苦情や問い合わせなどの電話が発生しないような理想的な震災時応急復旧目標期間は1週間であると考えられた。