Present state, existing problems and future ideal of decision process of design load, especially of snow load, are considered in relation to social situations, natural conditions and their evaluation methods. We proposed the idea that social ripeness such as population increase rate, average span of life, spread level of education, accumulation of social capital, social demand for maintenance of environment etc. would be a good index in load decision procedure for the social demand level of structural safety.
For the purpose of spreading the load and resistance factor design (LRFD), we have agreed that formulating a system that designers and owners have the opinion in the level of structural safety would be effective and convenient. For making this "menu", the importance of research and observation of snow load has suggested. with several indispensable factors for decision of design snow load.

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This report presents and introduces a research on radar polarimetry of microwave and millimeter wave remote sensing conducted at the University of Illinois at Chicago under the direction of Professor Wolfgang M. Boerner. An introductory explanation to RADAR POLARIMETRY and its applications are given. First, the basic definition of a wave polarization is introduced, relating to a scattering characteristics of radar target, which, in turn, leads to the polarimetric theory. Then, the theory is applied to a specific example of radar image, i. e., of San Francisco Bay Area, obtained by NASA-JPL, in order to enhance image contrast.
By using the highly advanced radar polarimetry, it is possible to enhance and optimize a image contrast of target and to improve the radar performance significantly. This polarimetric radar has an ability of eliminating background noise and speckles, especially in a strong clutter enviro-ment, which makes target detection and identification possible. Thus the radar polarimetry will play an important role in the high resolution radar remote sensing in the future.

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Fundamental discussion on the landslide in relation to snowmelt water is described.
(1) Several types of classification of landslide is not systematic in special reference to the water behaviour. Practical slide appears frequently under deep snow circumstance which is fairly syste-matic more than the rain circumstance. (2) Slide generation is explained by the mechanical balance, whereas frequently clay layer, defined geologically, is observed at the slide plane. The writer proposes a new model such that a clay layer is grown in long years by successive snowmelt water, and then it is required that new discussions on the landslide. (3) The effect of snowcover on the slide is described on the two points of weight and snowmelt water.

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It has been found that many landslides occur in snowy areas. According to our researches, the relation has been found between the occurrence of landslides and the depth of snowcover. In order to clarify this phenomenon, an automatic observation apparatus was introduced and an artificial landslide was produced. It was suggested that the landslide would be predicted by the investigation of constant strength c and φ of clay in the sliding zone, the behavior of the compound shearing force depending on the gap hydraulic pressure and the pressure of the air enclosed in the ground, and the worsening of sliding zone of permeability.

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