In this study, we improved the Guelph Permeameter (GP) method for the in-situ measurement of soil hydraulic conductivity. The new device has a simpler structure and a smaller diameter than conventional models, making it easier to insert into narrow wells drilled in the soil layer on mountain slopes. Moreover, numerical simulations replicating GP measurements were conducted using the water retention and permeability data from 250 forest soil samples to propose parameters and correction formulas for practical use. As a result, recommended parameter values for forest soil are presented for the soil constant (α^＊) and shape factor (C), which are necessary for calculating the saturated hydraulic conductivity (KS) from the steady-state infiltration volume (Q ). Furthermore, the effects of various measurement conditions on Q such as initial pressure head (ψ_i), the distance from the bottom of the well to the impermeable layer (S), and water injection time (T), were examined. The effect of ψ_i on Q was small, except under wet conditions where ψ_i>－50 cm. Since Q is underestimated when S is in the range of 0 ≤ S /H＜3 (where H is the well water depth), a correction formula was proposed. Additionally, because Q is overestimated if it does not reach a steady state, we propose a method using the infiltration volume at T＝10 min (Q_ST10) and a correction formula. Using the proposed device and correction formulas, K_S can be measured at any depth on mountain slopes in a relatively short time with sufficient accuracy.

Sand fences are effective devices for controlling wind-blown sand. They are built using different materials and employ various configurations in many locations around the world. A considerable amount of knowledge for the engineering use of sand fences has been developed. However, there is limited knowledge regarding sand fence configurations, and it has not been widely distributed. Thus, a brief literature survey was conducted to collect existing knowledge. The main findings of this survey are as follows: (1) The fundamental alignments of sand fences are the straight, straight with side spurs, zigzag, transverse, and perpendicular alignments. Other configurations can be expressed by combining and modifying these alignments. (2) The straight alignment is commonly used since it allows the area to be protected with the shortest possible extension, minimizing installation costs. (3) The zigzag and transverse alignments are employed when the prevailing wind blows obliquely to the shore. The zigzag alignment is particularly useful for regions with multiple wind directions. (4) The straight with side spurs and perpendicular alignments are used when the prevailing wind blows parallel or nearly parallel to the shore. (5) These alignments are arranged this way because the trapping efficiency of sand fences functions best when they are positioned perpendicular to the wind direction. The choice of configuration depends on the specific purpose of the sand fence. To create a new foredune, the straight, zigzag, and transverse alignments are commonly employed. To protect, restore, enhance, and transform existing foredunes, combinations such as straight-transverse, straight-zigzag, or straight-perpendicular alignments are applied. To prevent the inflow of beach sand into residential areas, the straight alignment is frequently used.