This review article discusses the history of applied geomorphological research in Japan after World War II. Initially, the focus was on postwar reconstruction and natural disaster management. Later, researchers started using applied geomorphology to address environmental problems. Today, applied geomorphology research is being conducted in synchronization with other fields’ awareness of environmental conservation issues. As social needs related to environmental issues are expected to increase in the future, applied geomorphology research in Japan is expected to develop to address these needs.

In Japan, the management of coastal land is under the jurisdiction of several agencies, and each agency is set up in accordance with provisions of relevant laws. The port area is managed on the basis of the Port Law, the farmland near the coastline including the coastal forest is managed by the Forest Law, and the other areas are controlled by the Seacoast Law. At the same time, the academic system is separated corresponding to these works. Accordingly, the local optimization method has been widely employed in solving the issues in each area and the comprehensive view regarding the management of the extensive area considering the overall sediment budget has been lacking, resulting in the disharmony in coastal zone. In this study, the conservation of the coastal zone in view of the comprehensive management was considered, taking a coast with approximately 40 km length between Oarai and Kashima Ports facing the Pacific Ocean. When an offshore breakwater is constructed on such a coast, beach erosion often occurs on nearby beaches of the breakwater by the formation of a wave-shelter zone associated with the extension of the breakwater because of the occurrence of longshore sand transport from outside to inside the wave-shelter zone. Both bathymetric survey data and aerial photographs in the study area collected since 1979 were analyzed. It was found that 7.9×10⁶ m³ of sand was deposited between 1979 and 2011 inside Oarai Port, resulting in the mean shoreline recession of 23 m in the other areas. It was concluded that it is important to consider the conservation of the entire area instead of local optimization at a local coast in view of geomorphological viewpoint.

This study explores the interplay between forests and landform processes, focusing on the integration of forest science and geomorphology. Both disciplines study processes related to water, sediment, and ecological factors. Hydrogeomorphology, which examines water circulation and landform changes, aids forest management through ecosystem conservation, erosion control, and land stability. Forests play a significant role in landform changes, riverbanks, channel morphology, and sediment transfer, resulting in mosaic forest structures. The significance of zero-order basins has been highlighted by studying small headwater basins and their relationship to long-term landscape change and shorter-term geomorphic processes. Recognizing watersheds as interconnected networks beyond headwater basins has enhanced our comprehension of forest-landform interactions. Both living and dead trees acting as ecological engineers influence geomorphic processes, including slope stability, soil erosion, and channel forms, whereas geomorphic processes such as mass movement strongly affect large wood dynamics. Understanding these processes requires considering temporal and spatial scales, and remote sensing technologies enhance research for sustainable resource management and disaster prevention.

Artificial land transformation in lake-catchment systems is engraved in lacustrine sediments, which are precious records for evaluating transformation processes as well as landform changes. Three types of land transformation are picked up for discussion: land reclamation, sand-control dam construction in catchments, and artificial channel construction connecting different catchments. Changes in sedimentation rate and physical properties respond to the progress of land reclamation in the catchments. Rapid decrease in grain density of lacustrine sediments and decrease in sedimentation rate are observed just after sand control dam construction. Increase in sedimentation rate is found in lake-catchment systems with additional catchments due to artificial channel construction.