Estimating Losses from Future Earthquakes (1989) / Chapter Skim
Currently Skimming:
9. Conclusions and Recommendations
9. Conclusions and Recommendations
Pages 66-77
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 66... ...
9 Conclusions and Recommendations i SUMMARY GUIDELINES FOR MULTIPURPOSE, [ARG~SCA[E EARTHQUAKE LOSS ESTIMATES This chapter presents the panel's conclusions and recommendations for conducting general loss estimate studies of the type currently being funded by FEMA and primarily intended for use by local and state governments for disaster response and mitigation planning, and to aid in the formulation and implementation of near- and Tong-term strategies for earthquake hazard reduction. Study Preparation and Planning The objectives and scope of a study must be defined clearly and early in a study.
|
From page 67... ...
Classification System for Buildmge The primary purpose of a classification system is to group buildings according to their seismic resistance for loss estimation purposes. Choice of a classification system depends on the availability of information relating ground motion to damage and on the funds available
|
From page 68... ...
It generally is not feasible to inventory all buildings individually, and attention is better focused on buildings that are seism~cally suspicious or are important to emergency response following an earthquake. Even when buildings are inventoried individually, they may subsequently be grouped regarding estimated losses, to help avoid legal and political problems that may result from singling out specific buildings as being hazardous.
|
From page 69... ...
prefers a method set forth by ATC in which casualty rates are linked to degree of damage and class of construction; this is a rational approach but must be used with considerable judgment. Estimates for the number of people requiring shelter are also important for planning of postdisaster operations, and for this purpose an well as for casualty prediction it is necessary to forecast the amount of severe damage rather than just the mean overall loss.
|
From page 70... ...
Unfortunately, to do this systematically is a major and expensive task, and it may be necessary to rely on the judgment of experts. ATC has developed a rational sequence of steps for developing DPMs for structures affected by ground failure, once such areas have been identified by geologists and geotechnical engineers.
|
From page 71... ...
Indirect Losses It is not yet possible to make reliable quantitative estimates of the potential losses from fire following an earthquake, but a study should emphasize the functionality of the water supply system and the highway and street infrastructure as they relate to Refighting capability. It should also note high-risk areas or factors, such as time of year and weather.
|
From page 72... ...
This independent review is not suggested out of concern over the quality of past projects but to increase confidence in the results of future studies, to ensure better documentation of the methods used, and to conform to validation procedures generally accepted in the scientific and engineering disciplines User Needs The foregoing guidelines respond to several of the identified user needs: involvement of local personnel, selection of the scenario earthquake~s) , establishment of inventories with continued use for multiple purposes, disaggregation of inventory and losses to the smallest political unit consistent with the principle of averaging losses over an adequate number of facilities to ensure statistical validity and anonymity, and the reporting of the loss study results.
|
From page 73... ...
While no one can promise that a loss study will lead to the passage of improved building or land-use ordinances, it is possible to schedule statewide conferences, as well as legislative briefings, for building officials and city planners following the completion of a loss study to consider its implications. State and local offices of emergency services can be expected to take a new loss study's findings into account in their earthquake disaster response planning, and this emergency plan revision effort can be scheduled to begin when the loss study is completed.
|
From page 74... ...
Two examples from the inventory part of the problem are: Where an exact inventory exists, such as with unreinforced masonry buildings in I`os Angeles, compare these hard data with the inventories established by approximate methods; Where an approximate loss estimation inventory has been prepared for a region, and this inventory can be disaggregated to small areas, prepare for comparison a complete inventory of one or more categories of buildings for a small area. Corresponding opportunities will occur for other components of an overall methodology, for example, predicted and actual intensity of ground motion, or comparison of maps showing probable ground failure zones with maps locating actual failures prepared after an earthquake.
|
From page 75... ...
The NOAA-USGS method has featured the use of experienced earthquake engineers and locally knowledgeable real estate consultants or building officials to field sample a study area and relate the samples to land-use maps. The inventory method that would be most commonly used in the ATC-13 approach (Level 2)
|
From page 76... ...
As part of this effort, there should be a renewed attempt to develop a satisfactory quantitative scale for the damaging potential of ground motion. It is likely that using more than a single groundmotion parameter will be necessary.
|
From page 77... ...
77 to fund and publish this statistical type of data has often been lacking. ~ addition, emphasis must be placed on collecting data for the occurrence and nonoccurrence of collateral hazards, the performance of lifelines, nonstructural components, and emergency facilities, and the containment or release of hazardous substances.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.