关于发布地震预报的抉择
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摘要
地震预报是人们讨论的一个热门话题。当前国际上普遍认同的一个基本事实是 ,地震预报水平远远未达到实用化的阶段。无庸置疑的是 ,作出发布短临预报的决策 ,是防震减灾工作中一项难度最大的工作。它长期困扰着各国地震工作部门和政府行政部门。公开发布地震预报 ,主要考虑因素有 :短临地震预报能力 ,作短临预报需付出的代价 ,以及地震预报公开发布后将会取得的实际收益。对以上三个因素权衡得失 ,趋利避害 ,注重实际效果。如果我们将这三个因素用预报效益来联系 ,那么 ,预报效益则等于预报实际取得的收益与发布地震预报必须付出的代价之比。若比值大于 1,则可公开发布 ;如比值小于 1,则不宜公开发布 ;当比值接近 1时 ,需同时考虑预报意见的信度这个因素。我国不同地区由于其经济发达程度、人口密度、国土财富率相差甚大 ,因此在用上述三个因素作是否公开发布地震预报的抉择上显然其结论是不同的。本文认为 :1 5 5级以下地震 ,东部和西部直接经济损失 (人民币 )约为 8亿元和 2亿元 ,经济上公开发布代价远大于当地所取得的实际收益 ,人员伤亡不超过 10人。因此无论东、西部均不宜公开发布地震预报 ,我们将 5 5级地震定为公开发布预报的震级下限。2 对于 5 5级至 6 5级地震 ,我国东部地区的直接经济损
Earthquake prediction is one of the favorite topics people discuss frequently A basic fact generally acknowledged all over the world is that the level of earthquake prediction is far from the stage of practical applications Without a doubt the decision making and the implementation of issuing a short term or imminent prediction to the public is the most difficult work in the earthquake preparedness and disaster reduction work It has long been perplexing the seismological departments and administrative departments of the governments of all countries The main factors to be considered before issuing an earthquake prediction to the public can be summarized as follows:1 the capability of making a short term/imminent prediction,2 the cost to be paid for the short term/imminent prediction,3 the practical benifit expectable from issuing the earthquake prediction to the public With respect to the abovementioned three factors, it is extremely important to weight gains and losses carefully and to stress their practical results so that advantages could be gained and disadvantages could be avoided If we use the concept of prediction benifit to link the three factors together then the prediction benefit equals the ratio of the expectable practical gains due to the prediction to the cost to be paid for issuing the earthquake prediction If the ratio is greater than 1, it is suitable to issue such a prediction publicly However, if the ratio is less than 1, then it is unsuitable to issue such a prediction If the ratio is close to 1, then the factor of the predictions reliability should be considered in addition Taking these three factors as the criterion to determine whether an earthquake prediction should be issued to the public, different conclusions could be reached for different regions of China due to large differences in their development degree of economy,in population density, and in amount of wealth on unity territory: 1 For earthquakes of magnitudes below 5 5, the direct economic losses are expected to be about 800 million yuan and 200 million yuan for East China and West China respectively Economically, the cost for a public issue is far greater than the practical gains The casualties due to such earthquakes will be less then 10 persons for both regions Therefore, it is unsuitable to issue such predictions to public in both East China and West China, and we take earthquakes of magnitude 5 5 as the lower limit of magnitude to issue predictions publicly 2 For earthquakes of magnitudes between 5 5 and 6 5, the direct economic losses are expected to be about 1 billion odd yuan and about 300 million yuan for East and West China respectively In East china, the cost for a public prediction will still be greater than the benefit due to a public prediction However, the casualties could be reduced greatly In principle, for such earthquakes, it is appropriate to make a public prediction within certain limits In West China, however, predictions of such earthquakes are appropriate to be issued publicly 3 For earthquakes of magnitudes above 6 5, it is not appropriate to take economic costs for a public prediction as the factor to be considered in determining the problem of public issuing of a prediction Predictions of such earthquakes should be issued to the society in both the economically developed East China and economically underdeveloped West China
Earthquake prediction is one of the favorite topics people discuss frequently A basic fact generally acknowledged all over the world is that the level of earthquake prediction is far from the stage of practical applications Without a doubt the decision making and the implementation of issuing a short term or imminent prediction to the public is the most difficult work in the earthquake preparedness and disaster reduction work It has long been perplexing the seismological departments and administrative departments of the governments of all countries The main factors to be considered before issuing an earthquake prediction to the public can be summarized as follows:1 the capability of making a short term/imminent prediction,2 the cost to be paid for the short term/imminent prediction,3 the practical benifit expectable from issuing the earthquake prediction to the public With respect to the abovementioned three factors, it is extremely important to weight gains and losses carefully and to stress their practical results so that advantages could be gained and disadvantages could be avoided If we use the concept of prediction benifit to link the three factors together then the prediction benefit equals the ratio of the expectable practical gains due to the prediction to the cost to be paid for issuing the earthquake prediction If the ratio is greater than 1, it is suitable to issue such a prediction publicly However, if the ratio is less than 1, then it is unsuitable to issue such a prediction If the ratio is close to 1, then the factor of the predictions reliability should be considered in addition Taking these three factors as the criterion to determine whether an earthquake prediction should be issued to the public, different conclusions could be reached for different regions of China due to large differences in their development degree of economy,in population density, and in amount of wealth on unity territory: 1 For earthquakes of magnitudes below 5 5, the direct economic losses are expected to be about 800 million yuan and 200 million yuan for East China and West China respectively Economically, the cost for a public issue is far greater than the practical gains The casualties due to such earthquakes will be less then 10 persons for both regions Therefore, it is unsuitable to issue such predictions to public in both East China and West China, and we take earthquakes of magnitude 5 5 as the lower limit of magnitude to issue predictions publicly 2 For earthquakes of magnitudes between 5 5 and 6 5, the direct economic losses are expected to be about 1 billion odd yuan and about 300 million yuan for East and West China respectively In East china, the cost for a public prediction will still be greater than the benefit due to a public prediction However, the casualties could be reduced greatly In principle, for such earthquakes, it is appropriate to make a public prediction within certain limits In West China, however, predictions of such earthquakes are appropriate to be issued publicly 3 For earthquakes of magnitudes above 6 5, it is not appropriate to take economic costs for a public prediction as the factor to be considered in determining the problem of public issuing of a prediction Predictions of such earthquakes should be issued to the society in both the economically developed East China and economically underdeveloped West China
引文
[1] 国家地震局未来灾害损失观测研究组 中国地震灾害损失预测研究 [M] 北京 :地震出版社 ,1990
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