Recent disasters caused by heavy rain events include 2018 Japan floods (July 2018), Typhoon 19 (October 2019) and the following heavy rain event, and July 2020 heavy rain disaster, and July 2021 heavy rain disaster. Such disastrous heavy rain events are expected to occur more frequently as climate change progresses, and it is important to update information on water bodies such as rivers, reservoirs and coastal waters. This study focuses on measurement and computational aspects of underwater topography.
Longitude and latitude components of ellipsoidal coordinates recorded by a GPS receiver are transformed to rectangular coordinates, and combined with vertical components including data recorded by an echo sounder unit so that underwater topographic data are obtained. Mappings on finite dimensional spaces of continuous functions defined on triangular meshes are formulated, and their iterative computations give rise to an underwater topography. Our techniques are illustrated the mappings with data obtained in measurement conducted in a reservoir called Kojima Lake, Okayama Prefecture, Japan.

He works in research areas of applied mathematics, and his research fields include underwater topography and microbial depolymerization processes. His recent academic activities include joint studies on measurement and computational analysis of underwater topography with Mr. Satoshi Iwakami, Mr. Masahiko Tamega, Mr. Masahide Sanada, Mr. Michiaki Mohri, Mr. Yoshitaka Iwakami, Mr. Naoki Okamoto, Mr. Eishi Mitsui (Earth Rise Company, Inc., Okayama, Japan), and Dr Shuji Jimbo (Visiting Researcher, Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan). He specializes in development and application of mathematical techniques including mathematical modeling, inverse analysis, and numerical simulation.