Unit-graph model to estimate the daily streamfiow was developed on the basis of distribution graph method. The results of evaluating the application of the model to Nakdong watersheds were generally satisfactory and this model would be the groundwork of the "Unit-graph model for daily streamflow in Korean watersheds".eds".uot;.

This paper attempts to qualitatively characterize scour erosion processes near USGS constriction type-I structures with vertical embankments and abutments. The scour dimensions and rates of sand beds around the structure models were measured in a rectangular flume. The test results showed that scour took place at a rapid rate at initial stages, which were followed by a stage of slow and general scour with greater extends. The maximum scour depth was observed near upstream corner of embankments. Empirical relationships for scour dimensions were derived, that were based on the results from a dimensional analysis of scour processes.

Through the hydraulic model test, a more convenient and accurate method of deter- mining discharge coefficients in the sluice type of tide gates can be derived by the use of aubmergence ratio as a parameter. The results obtained are summarized as follows; 1. Discharge coefficients under submerged flow conditions can be obtained by the application of sutmergerice ratio (S) to the free flow equation of the broad-erested we r. 2. The critical submergence ratios (Scr) for the flat basin and the broad-crested types of sill have the same value of 0.8. 3. Under free flow conditions, the discharge coefficient (m) are 0.37 and 0. 35 for the flat basin and the broad-crested types of sill respectively. However, when submerged flow condition exists, the discharge coefficients for both types of sill is given by a regression equation of discharge coefficients (IL) on submergence ratios (8) expressed as; m 1.3- 1. 17S. 4. The relationships between S and Froude number (Fr), for the flat basin and the broad-crested types of sill are Fr=2. 79-2.495 and Fr2.5=5. 7-6.16S respectively. From the above relationships, it can be concluded that m can also be expressed in terms of the Froude number which is a very relevant hydraulic parameter of the open channel hydraulics.

A depth-averaged two dimensional model TIFS was developed from simplified basic flow equations. The model was applied to tidal computations for the Biin Bay area near the Gunsan port. Vertical tides and tidal velocities for the tested was simulated for neap and spring tides. The simulation results were in good agreement with the obserbed data. This paper also attempts to evaluate model sensitivity from different initial conditions, roughness coefficient, time increments, and water depths. Among the selected input parameters, water depth and roughness coefficient were found to significantly affect vertical and horizontal tides.

The governing differential equations and the boundary conditions for the free vibra- tion of the unsymmetric parabolic arch with fixed ends are derived on the basis of the equilibrium equations and the D'Alembert principle. The effect of the rotary inertia as well as the extensional and the flexural deformations is considered in the governing differential equations. A trial eigenvalue method is used for determining the natural frequencies. The Ru- uge-Kutta method is used in this method to perform the integration of the differential equations. The detailed studies are made of the lowest three vibration frequencies for the par- abolic chord length equal to 10m. The effect of the rotary inertia is analyzed and it's numerical data are presented in table. And as the numerical results the frequency versus the rise of arch and the radius of gyration are presented in figures.

In this paper. the characteristics of mechanical behaviour due to various edge-ratio of uniformly loaded clamped skew-~plates has been described. In this study, the skew-plate was discretized using 8-noded isoparametric element and Mindlin's plate theory was adapted in finite element formulation. The edge-ratio 0.5,0.8,1.0,1.2,1.5,2.0 and 2.5 were considered. Hence, five cond- itions of the skew-angle, the seven levels of edge ratio were tried. When the edge-ratio was 2.5 or the edge-ratio was 2.0 and the skew-angle was less than 45 degree, the behaviour of the uniformly loaded the skew-plate with all edges clamped was independent of the skew-angle.