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Micro-relief surface depression storage is one of the dynamic components of the rainfall-runoff process. The quantification of the effect of rainfall intensity and duration on the micro-relief was the subject of this study. Micro-relief measurements were made on 88 soil bin samples before and after the application of simulated rainfdl events. The surface depression changes are described with empirical equations, using basic rainfall, surface hydrology, and soil parameters and their cross products as independent variables. A rainfall-runoff model demonstrates the value of a dynamic description of the surface depression storage function.

Micro-relief surface depression storage is one of the components of the rainfall-runoff process. The quantification of surface depression storage values and a depth-storage model to describe the storage was the subject of this study. Point measurement data were collected on 258 surfaces of 5 soils and three artificial surfaces. Five methods of computing storage, 15 depth-storage models, two depth increments, and six grid spacings were investigated. The 1-inch grid computational method, 0.1-inch depth increment, and 1-inch grid spacings were recommended. The surface depression storage function is best described by the model S = aDb, which relates surface depression storage as a function of depth with two equation parameters. Equations for describing the surface depression storage model parameters have been developed.

The movement of fallout 137Cs carried by soil particles was studied as an indicator of erosion and sedimentation in the Allerton watersheds and 4-H Memorial Lake located near Monticello, Illinois. Sediment deposition was greater in the waterway draining from watershed IB than in the waterway from watershed IA. At the average rate of 2.3 cm/yr of sediment deposition in the lake (from 1954 to 1979), there will be a loss of over 2 meters of water depth in the next century. However, there appears to be a decreasing rate of sediment deposition in the 4-H Memorial Lake as a result of improved conservation practices on the watersheds and the increased effectiveness of vegetated waterways and buffers for retaining sediment.

LABORATORY studies were conducted to study the effects of a sequencing rainfall intensity on the aggregate and primary particle-size distributions of eroded soil. Rainfall intensities of 25 mm/h (low intensity) and 64 mm/h (high intensity) were applied to Flanagan and Dubuque silt loam soils. All intensity combinations were used. Initially, the clay percentages of the eroded material were greater and the silt percentages were smaller than those of the original soils, but as rainfall continued, the primary particle-size distribution of the eroded soils approached those of the original soils in most cases. Low-intensity rainfall produced eroded material with higher percentages of clay-size aggregates than did the high-intensity rainfall. The intensity of the first hour rainfall had little effect on the size distribution of the eroded material from the second hour rainfall for each soil. However, differences in the primary particle-size distributions of the eroded material were observed when the two soils were subjected to a first hour high-intensity rainfall. The intensity of the first hour rainfall did not affect the runoff or eroded-material quantities of the second hour rainfall.

The firm JAMCO, Inc. has concentrated on making some of the lesser known sports more popular, using electronic timing devices and display systems. The computer has been used principally (1) to store and retrieve historical information about the sport and its competitors, (2) to analyze data generated by automatic and semiautomatic interval timing equipment, and (3) to operate electronic display equipment as a visual aid to spectators.