The surveying problem is an important one which had considerable impact on 

 this study. A good series of surveys is composed of two parts: a stable sys- 

 tem of relocatable bench marks and accurate surveying. Accurate bluff survey- 

 ing is difficult because, regardless of the method used, small errors in 

 distance or elevation can lead to large errors in bluff and beach volumes. 

 The following guidelines may be useful in planning a similar program of 

 surveying : 



(a) Establish a series of bench marks for each line that extend 

 from the most stable point above the active erosion to a primary bench 

 mark about 100 meters inland, or farther. Tie the primary bench mark 

 into local cultural features and into the state coordinate system. 



(b) In addition to surveying the active part of the bluff, occa- 

 sionally survey the stable part of the bluff to the primary bench 

 mark. 



(c) Use the most accurate surveying method available. Probably 

 the best method would be to use electronic distance measuring (EDM) 

 equipment and a transit or theodolite. This would give precise dis- 

 tances and elevations without having to either move the instrument or 

 read stadia intervals. 



(d) Keep careful notes as to the location of bluff crest, bluff 

 base, waterline, and sand sample locations. Photos are also useful. 



It should be realized that although long-term measurements may not be planned, 

 future researchers may want to reoccupy the profile lines. 



Two major improvements to the surveying program described here are needed 

 to unravel the complexities of the processes. One is detailed wave data for 

 each profile site, and the other is the inclusion of the alongshore dimension 

 at each site. Instead of single profile lines, carefully selected reaches of 

 lakeshore about 1 kilometer long should be studied. Daily wave and current 

 data should be collected by visual observers. Detailed wave hindcasts would 

 also be useful and would provide uniform wave data. 



In addition, detailed information on periods of ice cover is needed to 

 identify, when ice prevents erosion. In areas where it is important, some 

 measure of ground waterflow and its effect on the bluff is needed. 



Two different sets of data are needed — one which examines long-term 

 changes over a complete lake level cycle, and short-term measurements to 

 quantify the effects of storms. It is not sufficient to monitor beach changes 

 just during peak lake levels. Measurements during transition periods and 

 periods of low lake levels, particularly during major storms, are also 

 needed. Long-term changes may best be studied by a series of regular annual 

 or semiannual surveys or high-quality vertical air photos. 



This report and the two previous ones by Davis, Fingleton, and Pritchett 

 (1975) and Davis (1976) have illustrated the complexity of Great Lakes shore 

 processes. They are useful in characterizing the eastern Lake Michigan shore- 

 line and in quantifying the changes expected during a period of peak lake 

 levels. The reports have also identified the difficulties inherent in 

 monitoring lakeshore changes and are therefore useful in planning future 

 studies. 



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