the property is sold during a survey period, the new owner should be contacted 

 to explain the work that has been done on his property and the purpose of the 

 study. The importance of the continued use of his land must be stressed, 



3. Procedures for Establishing a Base Line . 



Survey accuracy for establishing local control for base lines should be 

 third order, one part in 5,000 for horizontal control and 0.05/d or 12 

 millimeters /k, where d and k are the distance of level line in miles 

 or kilometers, respectively, for vertical control. Traversing and leveling, 

 or other third-order techniques, should be used to establish the horizontal 

 and vertical control, respectively. 



III. MONUMENTING, REFERENCING, AND DOCUMENTING 



1. Monument ing . 



In order for it to serve its intended purpose, a base line must be properly 

 monumented. The monuments must have a degree of permanence, be positively iden- 

 tified, and be easy to locate and occupy. The Appendix provides a helpful 

 checklist for monumenting. 



Because the permanence of a monument is affected by the weather, waves, 

 erosion, and man's activities, including vandalism, consideration must be given 

 to the monument's construction and placement. The potentially harsh environ- 

 ment on the beach must also be considered when selecting the type of monument 

 to be used. The lifespan of the materials to be used and the resistance of the 

 monuments to movement are important in an area where a monument may be subjected 

 to freeze-thaw, windblown sand, waves, and erosion. 



Detailed descriptions of the types of monuments, their construction, and 

 placement can be found in a variety of sources, including Larrabee (1954), 

 Gossett (1959), Woodward (1967), and Baker (1968) for a general discussion of 

 monuments; Davis, Foote, and Ra3mor (1928) on pipe monuments; Kulp (1970) on 

 deep control points; and U.S. Army (1970) on concrete monuments. While a 

 detailed discussion of monumenting is beyond the scope of this report, there 

 are some considerations that should be raised. First, fixed points may be used 

 instead of actual monuments. These fixed points could be any stable objects, 

 such as a fire hydrant, telephone pole, foundation corner, or curb. One advan- 

 tage of using such points is that they are less attractive to vandals. A 

 second advantage is that objects such as piles, poles, and hydrants are likely 

 to be resistant to waves and currents. Disadvantages of such features include 

 settlement and the possibility of disturbance. 



There are several procedures that can be used to discourage vandalism, 

 although each introduces other difficulties. Obviously, a monument can be hid- 

 den in an area of dense foliage or can be buried, but these techniques make it 

 more difficult to find. This can be a significant problem when frequent sur- 

 veys are planned so the monument location must be very accurately described. 



Another technique is to simply increase the size of a monument, thereby 

 discouraging vandalism because of the effort required to move it. This has 

 the added advantage of reducing the necessity for repairs due to storms or 

 other natural or accidental events. When using a pipe as a monument, a plate 



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