ABSTRACT DEVELOPMENT OF CRITERIA FOR SHORE PROTECTION AGAINST

A practical design criteria is proposed to stabilize lake shores against wind waves. The wind waves in inland waterways such as rivers, canals, or lakes can and will cause substantial ero-sional damage if the waterway shore does not have natural or artificial protection. The orientation of the main watersheds and the general wind movement during part of the year in Illinois are con-ducive to the generation of damaging waves in lakes. Extensive lake shore erosion caused by wind waves is present in Illinois. A methodology was developed for estimating the height of wind waves in any lake for a given wind condition. Maximum wind speeds from five climatological stations in and around Illi-nois for the period of 1950-1972 were analyzed and a table was prepared showing the maximum wind speed for various durations and return periods. Statistical analysis of wind wave data collected from Carlyle Lake indicated that Rayleigh distribution fitted the wave height distribution reasonably well and that the nondimensional energy spcctra followed (f/f,,)-5 rule in the equilibrium range of frequencies. Boat-generated wave heights fitted ~ a ~ l e i ~ h distribution to some extent and a re-lationship was developed relating boat speed, maximum wave height, distance between the boat and the wave gage, and the draft of the boat