This study examines the long (A) and short (B) plan diameter, depth (D) and crosssection of kamenitza （also known as solution pan） on and around the quarry site of coral limestone at Yomitan coast, Okinawa Island, Japan. The growth rate of kamenitza was estimated from D, and the degree of its growth was discussed from shape of crosssection by supposing that the formation of kamenitza on and above the face of quarry started at stone cutting about 90 years ago and before then, respectively. Results of the measurement showed that the plan diameter and the ratio of A/B on quarry face were larger than that on above face. It follows that local relief in close association with pools was one of factors in plan size. The D in above face was larger than that in quarry face according to duration time, and the D in quarry was 70-90% of that in above face. The shape of cross-section was developed in several steps as follows; ship’s bottom → pan’s bottom → micro notch. These processes that corrosion progress downward at first and then laterally are based on the pooling of water according to the way and amount of water supply.

Digital Elevation Models (DEM) are well suited for characterizing the geomorphological features of a landscape. Different geomorphic types, including marine terraces, fluvial terraces, landslides, fans and sand dunes are distributed on the Noto Peninsula in Ishikawa Prefecture, Japan. We employed a DEM to examine the geomorphological characteristics of ancient dunes and old fans on the Noto Peninsula. Using a previous classification of geomorphic surfaces, we then performed a boring survey to characterize the facies of sediments. Since geomorphic analysis based on current topographic data is highly influenced by the anthropogenic development of landforms, we generated the DEM using aerial photographs that had been taken of the area prior to development in the region. Analysis of the slopes and eigenvalue ratios of the ancient dunes in the 1 m-DEM revealed that they were steeper and smaller than those of the old fans, respectively. Indeed, slopes and eigenvalue ratios appear to be well suited for use as indexes for distinguishing between ancient dunes and old fans.

Debris flow deposits consist of poorly sorted gravel beds composed of granite porphyry are distributed along the Nachi River, Wakayama Prefecture. In order to determine the age of sediment deposition, we carried out of calendar calibrated ¹⁴C dating using 22 wooden fragments collected from debris flow deposits. ¹⁴C dates indicate that 10 depositional events of debris flow during the past 14,000 years. These debris flow deposits derive from heavy rainfall events because ¹⁴C dates are inconsistent with the age of large historical earthquake along the Nankai-trough. Frequency of large-scale debris flow caused by heavy rainfall in the Nachi River is estimated 10³ years during the past 14,000 years.

In Nabeshima area in Nakatsu tidal flat facing the Suo-nada Sea, a slender sand bar has extended in extremely shallow sea in recent years, and connected to the other shore, resulting in the formation of a barrier island. The planform changes in the sand bar in Nabeshima area were investigated using aerial photographs taken between 1981 and 2010, and the deformation process was studied. Observed results were compared with the results of the numerical simulation regarding the formation of a barrier island on a sloping bed with a 1/40 slope, which was carried out by Serizawa and Uda (2013) using the BG model (a three-dimensional model for predicting beach changes based on Bagnold’s concept). The observed change in a barrier island in Nabeshima area and the calculated results were in good agreement in terms of the change in planview of the barrier. A mound was constructed as a headland using the dredged materials containing gravel in this area before 1981, and this artificial mound effected as a supply source of sediment for the development of a barrier.