Business Continuity Planning (BCP) holds great potential not only for reducing damage to a company from disasters but also for reducing damage to a community and reducing the environment load. This study specifically examines rainwater harvesting as part of a BCP model considering both environment load reduction (water saving effect) and natural disaster mitigation (water storage effect). First, particularly addressing an existing company, we summarize evaluation methods for each benefit and cost by introducing rainwater harvesting. Then, we formulate a decision-making model for the tank size that maximizes net present value. Furthermore, we implement a case study under realistic conditions set by the observed dataset such as the size of the company office building, the amount of evaporation from the biotope, and past AMeDAS rainfall data. The optimal tank size associated with the annual dispersion of cash flows is ascertained for the judgment of business feasibility. Results provide information related to the potential of the approach, suggesting better methodologies. The results are also available as an example for consideration of the development for District Continuity Planning (DCP) and other BCP models.

View full abstract

 Oyabe weir construted in the Oyabe River is used for the intake of agricultural water. Oyabe weir has three sluice gates that are operated during a flood. The outflow discharge is calculated using Toch’s formula. The discharge of Oyabe river is measured at the Tsuzawa discharge gaging station located 1.7 km downstream from Oyabe weir.However, the outflow discharge from the sluice gate differs from the river discharge measured at Tsuzawa gaging station during a flood.
 As described in this paper, the hydraulic characteristics of Toch’s formula were clarified by mathematical analysis emphasizing the classification of ‘submerged efflux’ and ‘free efflux’. A method for calculating free flow is discussed in this paper. For Oyabe weir, a new method of applying Toch’s formula that incorporates hydraulic characteristics confirmed through mathematical analysis is proposed. An effect of the new application method is discussed based on result estimated using the new method for field measurement data.

View full abstract

 The author surveyed recent directions in extreme precipitation studies in the U.S. based on participation in the 2014 California Extreme Precipitation Symposium and follow-up literature surveys. The annual symposium aims atsharing information related to meteorological and hydrological research development related to extreme precipitation that might cause flooding, and aims at applying that information to planning and management. More reliable PMP estimation is a recent direction, with background stemming from the fact that planning and design methods of hydraulic structures in the U.S. have changed, employing new technology. Specifically, current levee and dam safety programs started in the mid-1990s require more comprehensive decision-making of hydraulic structures based on risk analysis and PMP. The U.S. Bureau of Reclamation’s interim guidelines set 1/10,000 annualized failure probability as a rough safety criterion and apply special consideration if dam failure can be expected to cause more than 1,000 deaths, even if the failure probability is low. To support national-level storm analysis including PMP, the Hydrologic Engineering Center of the U.S. Army Corps of Engineers is developing a nationwide storm database and computer analysis tools.

View full abstract