The Dictionary of Landforms was edited and published in 2017 by the Japanese Geomorphological Union (JGU) as a part of its 35th anniversary projects. To commemorate its publication, a symposium: “Communication between Society and Geomorphology” was held with the aim of highlighting the professional role of geomorphology within society. This paper is a summary of the introductory lecture from the symposium with the further aim of reaching the general public. It is known that landforms have a direct impact on many aspects of human activity, such as habitation, agriculture and transportation. Most natural disasters, except those triggered by internal geomorphic agents such as earthquakes or volcanism, occur in different modes and magnitudes under the effects of landforms, i.e. the geomorphic species and setting at a given site. For this reason the expansion of accurate knowledge regarding geomorphology is essential within wide aspects of society. The Dictionary of Landforms, therefore, with its 8,626 extensive entries on all aspects of landforms in Japanese, will help the general public understand landforms and by doing so to contribute to Japanese society.

Current state and issues of terminology related with sediment disaster science were discussed along a history of technical development in disaster prevention measures in Japan. Most of scientific words used for sediment disasters and preventive measures have been interpreted from English or German to Japanese since Meiji-era. Additionally, various terms not only from natural science, such as hydrology, engineering, geology, geomorphology, volcanology, meteorology, but also from social science are used for describing sediment disaster events. When we have imported the technology of preventive measures from overseas, therefore, the various terminology could be mixed with Japanese original technical terms. This article is focusing on the difference between Japan and overseas in the definitions of geological and geomorphological terms related with sediment disasters. The “landslide” and “gully erosion” are typical examples of misunderstanding and/or broad interpretation of original terms by foreign language. To organize the terminology of sediment disasters, we have to clearly identify geomorphology and mass-movement from natural processes, as well, understand those processes are controlled by the combination of material and motion.

As per a recent case study, there appear to be problems regarding the concepts and terminology used in Japanese textbooks that often result in a communication gap between related branches of science. For some cases, solutions to these problems are presented here.

In Japanese high school textbooks, the definition of terms related orogenic belt differ between the fields of geography and geology, and this needs to be rectified. The classification of orogenic settings in the fields of geography is based on the outdated geosyncline theory and therefore requires revising. In the field of geology, a distinction between formation environments is important, as orogenic belts are classified according to the nature of the plate boundary (i.e., collision type or Pacific type), or orogeny-related supercontinent cycles and activity (i.e., active or inactive).

The importance of topography learning is increasing when disaster prevention education and Sustainable Development Goals (SDGs) etc. are enhanced. Topography learning in geography education is systematically positioned in the course of study instruction, but on the other hand the content dealt with in textbooks and lessons is left to each researcher and field teacher. For terrain learning, attention is important for learning, such as selection of concrete content of learning, understanding of scale feeling such as schematic diagrams. In addition, research on teaching materials based on technical terms and ideal teaching materials is required.

Newspapers write articles for a wide range of readers. It is difficult to replace technical terms with plain and easy words. There is also the possibility of damaging the original meaning of paraphrasing. I would like to consider newspaper articles and technical terms based on newspaper cases.

There are often gaps between academic language and language used in the general society. NHK, Japan Broadcasting Corporation defined terms and languages used for broadcasting as “broadcasting language”. Broadcasting language is necessary to accurately convey information to many people on public broadcast. Yamaguchi (2008) defined that “the term becomes socialized” that technical terms or academic language are used in media and the society. In the era when natural disasters become intense, such as by global warming, this paper is examined for disaster prevention and reduction, consider what should be the geographical terms related to disasters, from the viewpoint of science/risk communication in media.

Japan suffers from landslide hazards, especially in the granitic rock areas. In 2014, many slope failures occurred in western and central Japan and more than 70 people were killed. Granite weathering produces grus and core stones, which often cause severe landslides under intense rainfall. This phenomenon has been recognised for a long time; however, the weathering condition of these granitic areas has not been investigated. This study explored the chemical and mineralogical properties of samples from bedrock and soils in granite landslide areas. Granitic rocks taken from several areas of central to southwestern Japan were analysed. All of these areas have suffered from landslides in recent decades. A series of samples of bedrock, slip surface and surface soil samples were collected from these landslide-prone areas. For mineralogical and chemical properties, X-ray powder diffraction analysis (XRD) and SEM-EDS analysis were carried out. Quartz, k-feldspar, plagioclase and biotite were mainly found in bedrock samples, whereas clay minerals such as kaolin minerals, mica clay minerals and vermiculite or 14Å intergrade minerals were found in the soil samples. Based on the chemistry data, chemical weathering indices were calculated, including: Si–Al ratio, product index (PI), Si–Ti index, chemical index of alteration (CIA), chemical index of weathering (CIW), Vogt. ratio (V), plagioclase index of alteration (PIA), modified weathering potential index (MWPI), parker index (WIP) and Al–Ti index. These index values showed weathering progress in the order from bedrock, slip surface and upper surface soil. To consider climatic influence, the relationships between mean annual air temperature and chemical indices of CIA and Si–Al ratio were investigated. The CIA values for soil samples increased with temperature, whereas the Si–Al ratio decreased with temperature. Those values for bedrock had no correlation, which means that original bedrock condition is almost the same across these areas. On the other hand, there seemed to be no relationship between mean annual precipitation (1981-2010) and weathering indices. The results clearly show the effects of temperature on chemical weathering of granite landslide areas in central-southwest Japan.