Since permeability is the measure of the ease with which water moves through aquifer material, certain relationships must exist between permeability and the statistical parameters that describe the grain size distribution of the porous mediums. Experimental studies to investigate these relationships consisted of systematic variation of the values of the statistical parameters and evaluation of the corresponding permeabilities of the samples. The parameters investigated included measures of the average size, dispersion, skewness, peakedness, and modality of the sample distributions. Several graphs were developed that related permeability to the various statistical parameters. On the basis of these plots a group of curves was defined to predict laboratory permeability values for aquifer samples with random statistical distribution. This set of prediction curves incorporated only the average size and dispersion, because these parameters best described the relationship between permeability and the grain size properties of the porous mediums. These prediction curves were then used to determine the laboratory permeability coefficients for a group of samples obtained from a natural aquifer, and the results were compared with actual permeability values obtained from laboratory tests.

Previous studies of the scour of cohesive materials as presented in engineering literature and as obtained directly by personal contact are briefly reviewed. Exploratory tests for measuring scour resistance are described, and some correlated results are presented for a test involving scour by a vertical submerged jet impinging on the horizontal surface of a soil sample. The characteristics of the scour surface were observed for a remolded and a natural sediment, and the rates of scour were measured by the weight loss of the sample. The results are presented in terms of dimensional parameters. A new apparatus is described which is designed to permit a direct measurement of a uniform shear stress developed at the surface of a cylindrical sample of a cohesive sediment. Comments are made regarding the direction of future research in this area.

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Laboratory studies m a wind wave flume were carried out to investigate the macro-scale turbulence associated with wind waves and white cap conditions Velocity fluctuations m water were measured with a hot film anemometer and parametric correlations between wind waves and turbulence characteristics were established Measured data were recorded m analog form, digitized and stored on magnetic tape Auto - covanance functions and power spectral density functions were then obtained for all sample records Results showed that the depth of the penetration of the macro-scale turbulence increased rapidly with wind speed but the rate of penetration diminished at the higher wind speeds This rate of macro-turbulence penetration was found to vary inversely with wave height and wave steepness Most turbulent fluctuations having frequencies equal to or higher than the frequency of the ambient surface waves were confined to the zone of macro-turbulence penetration although some disturbances such as vortex rings and other turbulence associated with white cap wave conditions occasionally penetrated to greater depths It was found that the energy dissipation increased with wave height and that almost all wave energy dissipation was concentrated near the water surface.