You will find it very difficult to use soil survey data to try and estimate liquefaction potential. The CDMG methodology is listed in CDMG special publication 117 (Guidelines for evaluation and mitigating seismic hazards in California). The main difficulty is that liquefaction potential is defined by/linked to blow counts from geotechnical borings and water level data. It is very time consuming to gather that data from the local public works agencies. You then have the major problem of analyzing that data in a 3-D format. Historically, this was done either as a masters or doctorate (the only ones who could spend the time). The process is further complicated by the privacy laws in Calif. Because of copyright lawsuits, building plans can no longer be copied (in any form). Most building officals have expanded that ban to include soils reports (where the key data reside). The only people who can copy that data now are from the government. There are other problems. You have the problem of a very scattered data set and how to interpolate between data points (even in Oakland CA, data points can be miles apart) . there is also the question of the methodology. The CDMG method works well regionally even with poor/limited data. There is some question as to how well it works on a detailed/ local analysis. If you have any other questions, I would be more than glad to try and answer them. S. Figuers Calif State Board of Mines and Geology ---------------------------------------------------------------------- To unsubscribe from this list, send e-mail to [EMAIL PROTECTED] and put "unsubscribe MAPINFO-L" in the message body, or contact [EMAIL PROTECTED]
