Gaps Between the Transmission and Reception of Information on Rainfall Amounts
Kan Shimazaki, Hiroko Nakajima, Naoki Sakai, and Akiko Miyajima
National Institute of Earth Science and Disaster Resilience (NIED)
3-1 Tennodai, Tsukuba, Ibaraki 305-0006, Japan
In weather forecasts, the intensity of rainfall is often expressed either as a quantitative value – the amount of rainfall per hour – or using qualitative language such as “heavy rain.” To date, however, there has been no research into the extent of rainfall that is assumed by information receivers when presented with these qualitative terms. Thus, the present study examines the correspondence between rainfall evaluation and expressions using a rainfall generator. The large-scale rainfall experiment facility owned by the National Research Institute for Earth Science and Disaster Resilience was used to generate rainfall of 60, 180, and 300 mm h-1, and 21 experiment participants experienced this rainfall without knowing the rainfall amounts. Following this, the participants were asked to give feedback using a scale that correlated numerical expressions of rainfall amounts per hour with 10 language expressions such as “heavy rain” and “downpour.” The results revealed that rainfall rates of 60, 180, and 300 mm h-1 were evaluated by the participants as 135, 223, and 311 mm h-1, respectively. The 10 language expressions were felt to be stronger than the official criteria outlined by the Japan Meteorological Agency. In addition, there was no statistical significance among several expressions, suggesting that the qualitative language used to describe different rainfall amounts by information senders were not distinguished by information receivers.
-  Japan Meteorological Agency, Result of accuracy verification of weather forecast, http://www.data.jma.go.jp/fcd/yoho/kensho/yohohyoka_top.html, 2017. [accessed February 26, 2018]
-  Japan Meteorological Agency, Strength of rain and its expression, http://www.jma.go.jp/jma/kishou/know/yougo_hp/amehyo.html, 2017, [accessed February 15, 2018]
-  J. Asada, T. Katada, and Y. Oikawa, “A study on the acquisition of disaster information during the flood disaster in Koriyama at the end of August,1998,” Proc. of Hydraulic Engineering, Vol.44, pp. 307-312, 2000.
-  T. Katada, M. Kodama, and J. Asada, “Research on acquisition of disaster information and evacuation behavior in heavy rainfall disaster in Tokai district,” Advances in River Engineering, Vol.7, pp. 155-160, 2001 (in Japanese).
-  S. Irie, “Demolition of the Kinugawa River, How did the residents of Joso City evacuate? – Disaster information recognition and evacuation behavior survey of residents in “Kanto Tohoku heavy rain”,” The NHK Monthly Report on Broadcast Research, Vol.66, No.8, pp. 34-65, 2016 (in Japanese).
-  K. Tanaka, M. Umemoto, and E. Itoigawa, “Systematical organization of the obstructive factors of residents evacuation at heavy rain disasters based on 128 preceding papers,” J. of Social Safety Science, Vol.29, pp. 185-195, 2016.
-  Y. Uchikawa, K. Okabe, K. Takeuchi, and A. Tsujimura, “Communication and modern society – 1: Basic theory,” University of Tokyo Press, 1973.
-  S. Sato, S. Kure, S. Moriguchi, K. Udo, and F. Imamura, “Online information as real-time big data about heavy rain disasters and its limitations: Case study of Miyagi prefecture, Japan, during typhoons 17 and 18 in 2015,” J. Disaster Res., Vol.12, No.2, pp. 335-346, 2017.
-  K. Tanaka and T. Kato, “Perceived danger can be influenced by how the emergency information is expressed,” The Japanese J. of Cognitive Psychology, Vol.9, No.1, pp. 1-7, 2011.
-  M. Okamura, M. Tsukai, and T. Shimoaraiso, “Reliance on disaster warning and responses,” Infrastructure Planning Review, Vol.18, pp. 311-316, 2001.
-  S. Rayner and R. Cantor, “How fair is safe enough? The cultural approach to societal technology choice,” Risk Analysis, Vol.7, No.1, pp. 3-9, 1987.
-  P. Slovic, “Perceived risk, trust and democracy,” Risk Analysis, Vol.13, No.6, pp. 675-682, 1993.
-  T. Terpstra, “Emotions, trust, and perceived risk: Affective and cognitive routes to flood preparedness behavior,” Risk Analysis, Vol.31, No.10, pp. 1658-1675, 2011.
-  S. Holm, “A simple sequentially rejective multiple test procedure,” Scandinavian J. of Statistics, Vol.6, No.2, pp. 65-70, 1979.
-  H. Abdi, “Holm’s Sequential Bonferroni Procedure,” N. J. Salkind (ed.), Encyclopedia of Research Design, Sage, 2010.