Shigekatsu Endo

An observation of snow melting process from remotely sensed data

Abstract Observations of satellite images have shown that the snow melting in mountainous area proceeds more repidly in the east-facing slope of the valley than in the west-facing one. The energy for melting snow consists of the total from the atmosphere and from the solar rays. The diurnal variation of the solar energy into the snow in the east-facing slope differs from that in the west-facing slope. This causes the heighest value of the instantaneous energy for melting snow to occur in the west-facing surface. As one of the reasons for the above tendency, the difference of the heighest value to melt snow may be taken into account.

FUNDAMENTAL STUDY ON WAVE-INDUCED CURRENT NEAR SUBMEARGED WALL

A wave-induced current near submearged wall type breakwater was examined for the clarification of a dispersion system of waves energy and the preservation of sea area ecosystem. The turbulence quantity of a detailed wave-induced current was obtained by PTV measuring. The characteristics of wave-induced current, especially turbulence quantity, an instantaneous velocity and circulating range to the state of wave overtopping ware elucidated. It was found that the factor of waves energy dissipation is the interference of a return flow and incident wave in the front area of structure and be the splash with overflow and circulation by return flow in the back area.Numerical computations were performed by using DNS method. The calculation results agree well with the experiments and the adaptability of the analysis method was confirmed.

Experimental study on Dynamic Motion Control by Flat Plate Attached on the Pontoon

The experiments on this study were conducted to find the effective motion control by a flat plate attached on the pontoon, and also Wave response characteristics of several type of the pontoon were examined. Then, it was verified that the flat plate have worked effectively for motion control of a floating pontoon, especially against a wave with conparatively large wave steepness. It was confirmed that the dimension and attaching depth of flat plates are important factor for motion control of a floating pontoon. The most effective plate for motion control on these experimental condition is case 4. This method using a simple potential energy of fluid could be multiply applied to pontoon with other formed ones.

Investigation on Run-off of Residential Area with Infiltration Facilities

This report is delivered on run-off of residential area with infiltration facilities. The rainfall datas were classified into three cases. The results were as follows:(1) if it was even slightly rainfall, the ratio of run-off was 0.1 or less.(2) If it was peak shaped rainfall, the ratio of run-off was about 0.2 in cace of 20 mm/hr.(3) It was found that infiltration capacity of the facilities had not changed since field observation was begun.