The objective of this study is to model the processes involved in moisture content transition of wood chips in breathable, flexible containers in order to establish a drying method in an ambient environment. To achieve this objective, a model for a small size breathable container stockpiled with wood chips was developed and tested. The moisture content of the chips was measured periodically, while monitoring the internal temperature and humidity. The measurements were conducted under a constant temperature condition using a drying oven. The results showed that there were differences in decreasing moisture content rates between chips around breathable surfaces and those in other locations. The decrease in moisture content of the chips around the breathable surfaces followed an exponential curve, while that of the others followed the reverse S-shaped curve. Exponential model and logistic model equations were derived to describe these characteristics of moisture content transition respectively. They showed good finesses and the calculated transition of moisture content of a whole container using the models was also fitted well. One of the key parameters of the logistic model considered to determine drying speed was found to decrease with the distance from the breathable surface, as expected. However, the other parameter, which relates to the time at which drying begins could not be clarified.

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As intercepted subsurface flow can encourage road surface erosion in forests, it is neccessary to predict areas where this could possibly occur and to take some measures to prevent such erosion. The purpose of this study is to test the assumption that such locations can be predicted on the basis of the roadside drainage area. In this study, we recorded locations on four forest roads where road surface flow persisted over 12 h after rain events or where cross drains were added during maintenance activities, which were assumed to be subjected to intercepted subsurface flow. Results showed that the appearance frequencies of locations where there was persistent road surface flow or where cross drains had been added did not significantly differ in relation to the roadside drainage area. Further, these locations were often found near valleys; however, the proportions of the valleys within 20 m of the locations were not significantly different with respect to the drainage area of the valleys. These results suggest that there is no correlation between the roadside drainage area and locations that are subjected to intercepted subsurface flow and that such flow can occur near valleys with large and small drainage areas.

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