Alaska Section, American Water Resources Association

Michael R. Lilly, Alaska Section AWRA Northern-Region Director

I would like to invite you to the January 1999 Brown-Bag presentation by Dennis Bogren, PDC Inc. Please note this meeting is the second Wednesday in January. Dennis's talk will be a presentation on general surveying standards used in hydrology and issues associated with new datums. We look forward to seeing you. Please feel free to bring a colleague to the meeting.

January 13, 1999
Alaska Section AWRA, Northern-Region Brown-Bag Presentation
Alaska Department of Natural Resources, Large Conference Room
Noon to 1300

"An Overview of Geodesy and Surveying Accuracy Standards for Hydrologists"
Dennis Bogren
PDC Inc.

ABSTRACT

Two new datums have been accepted by both government agencies and the surveying community. NAD 83 (North American Datum of 1983) and NAVD 88 (North American Vertical Datum of 1988) have replaced the older NAD 27 and NGVD 29 datums. Datum selection is important not only for those using latitude/longitude locations but also for those using the Alaska State Plane Coordinate System. Coordinates generated in one datum cannot be successfully used into the other without transformation. Some transformation methods are less accurate than others.

In surveying there is a direct correlation between accuracy and cost. Knowledgeable use of surveying accuracy standards when writing hydrologic survey instructions can lead to better communication and reduced fees.