The Japanese public now has access to vast amounts of geographical information produced by many government agencies and media outlets on the tsunami caused by the Great East Japan Earthquake. Many maps and images not only inform the public about the tsunami damage area, but potentially help the public and policy makers understand the landscape damaged by the tsunami, and plan reconstruction. However, large amounts of publically available data still remain underutilized. This paper reports the results of time-series land-use analysis for selected cities along the Sendai and Sanriku Coast of Tohoku, Japan, based on currently available maps and aerial photographs, with two goals. First, the paper reports on GIS analysis of tsunami flood areas to quantify historical land use. Second, the paper examines the quality and problems of the spatial data now available for GIS analysis and public information. Landscape researchers need to consider whether the spatial data now publically available contain the information that answer the questions interesting the public, while exercising care that GIS analysis informs the public and policy makers without preempting public debate and allow various policy outcomes.