To study natural disasters, we must first know the magnitude of disasters, so it is of great significance to establish and improve the evaluation index system of natural disaster losses. For a long time, many scholars have explored the working standards, evaluation indicators and methods of natural disaster loss assessment, and established absolute measurement indicators such as disaster degree and disaster index; This paper studies the relative measurement indexes of disaster loss, such as relative disaster degree and disaster loss rate, as well as the classification standard of disaster loss rate and the conversion of natural disaster loss ratio, which provides a scientific and quantitative index system for describing and evaluating the size of natural disasters and their damage to social productivity, and lays a foundation for describing disaster intensity, disaster relief investment, disaster insurance and disaster reduction evaluation.
1, disaster loss
Disaster loss refers to the human death and social property loss (direct loss) caused by natural variation process, the damage caused by catastrophe process to social production and residents' life, and the investment (indirect loss) to repair the normal social order in the damaged disaster area. Disaster loss can be described by two indicators: loss size and loss degree. The magnitude and degree of disaster losses depend on many factors, such as disaster-causing factors, disaster intensity, population density in the affected areas, economic development, comprehensive disaster tolerance and post-disaster rescue. The difference is that the former reflects the absolute amount of disaster losses, while the latter reflects the relative amount of disasters.
Disaster is the process of natural disasters destroying the disaster-bearing body, and disaster loss is the loss of the disaster-bearing body. Therefore, in order to accurately describe disaster losses, we must fully consider the situation of disaster-bearing bodies, not only the size of disaster losses, but also the degree of disaster losses, both of which are indispensable. For example, two earthquake disasters with the same intensity, one occurred in sparsely populated and underdeveloped areas, and the disaster losses were small; The other occurred in densely populated and economically developed areas, causing heavy casualties and economic losses. However, the degree of disaster losses and the time required for post-disaster reconstruction and recovery are often much higher than the latter. Therefore, in order to establish a natural disaster loss assessment system, it is necessary to first clarify the concept and connotation of natural disaster loss.
Natural disaster losses are divided into two categories: casualties and economic losses [1]. Casualty losses include the number of casualties and the medical expenses of the injured, as well as the social welfare expenses of those who lose their ability to take care of themselves in work and life or cause lifelong disability and the funeral expenses of the deceased. Economic losses can be classified according to the economic types of property losses, such as construction, commerce and industry, or primary industry, secondary industry and tertiary industry. According to the development of social and economic activities, the most commonly used standard is the disaster-causing factor.
Divide the direct economic loss and indirect economic loss of natural disasters, and the total loss of social production invested in disaster relief and post-disaster recovery.
Direct economic loss refers to the sum of economic losses caused by the same disaster, including primary disasters and closely related secondary disasters. For example, a major earthquake, the collapse of houses and engineering structures, the destruction of fields and roads may also cause water, electricity, gas, fire and traffic jams. Its failure and economic losses caused by * * * can be regarded as direct economic losses of disasters. Because in such disaster assessment, it is impossible to distinguish between primary disasters and secondary disasters in a short time.
When the process of a disaster basically ends, the economic losses caused by the reduction, imbalance, slowdown and stop of production and technology of industrial and mining enterprises, commercial and financial exchanges, social welfare undertakings, social services and contract performance in management can all be regarded as indirect economic losses of the disaster. Compared with the direct economic loss, the indirect economic loss caused by the disaster is not only lagging behind, but also can last until the production in the disaster area gradually reaches the social production level before the disaster event after a large amount of reconstruction funds are invested in disaster relief and post-disaster recovery. Therefore, for some serious natural disasters, the indirect economic losses of disasters often account for a considerable proportion of economic losses. For example, after the 1976 Tangshan earthquake, China spent ten years rebuilding Tangshan destroyed by the earthquake. It took ten years of hard work and a lot of investment (the central government invested 2.5 billion yuan) to make it reach the pre-earthquake economic level. In other words, the earthquake of 1976 is equivalent to forcing Tangshan's economic life to be paralyzed and shut down for ten years. Therefore, we believe that the loss of economic production activities in the recovery period of normal social life caused by disasters can be regarded as indirect economic losses of disasters.
In the previous classification or calculation of disaster losses, a very important content was neglected, that is, the input part of disaster relief and post-disaster recovery after disaster events, which included the total amount of all social products he invested in disaster relief and post-disaster recovery, and we temporarily called it disaster relief losses. The total amount of social products invested in this part is regarded as a loss. Is that they did not create new social wealth according to the original social and economic life process,
But to make up for the destruction and pause of natural disasters to the social production part that has obtained social and economic benefits. It can be figuratively compared to supplement the "blood transfusion loss and hematopoietic function repair" in social and economic life. Most of the disaster relief losses come from social reserve funds and social security funds in national income. The former is a necessary condition to prevent the interruption of social reproduction process and ensure the normal development of the national economy, and is an integral part of the accumulation fund. In the physical form, it includes not only the reserves of various means of production such as equipment, raw materials and fuel, but also the reserves of major consumer goods such as grain. In addition, it also includes financial reserves in the form of value. The latter is the part of national income used to ensure the life of social members who have lost their ability to work and lack income sources. It includes the state expenditure on social relief, social welfare and labor insurance, as well as the public welfare fund in the collective ownership economy. For example, 1976, the 2.5 billion yuan invested by the central government during the recovery after the Tangshan earthquake should belong to the disaster relief loss.
Anyway. Natural disasters are the destruction of social property and social production by natural variation, and the loss of natural disasters comes from the expenditure or negative growth of social wealth accumulation and social production accumulation. Its composition block diagram is shown in figure 1.
2 natural disaster loss assessment and its standards
Natural disasters are the phenomenon of interaction between natural variation and society, and their measurement is the contradictory ratio between the intensity of natural variation and social defense ability, that is, the loss of social wealth caused by natural disasters. The loss caused by natural disasters is not only related to the intensity of natural variation, but also depends to a great extent on the economic development level, population distribution density and activity scope of the society at that time. Therefore, the loss of natural disasters is a function of social state. Doing a good job of natural disaster loss assessment is the basis of disaster reduction benefit analysis, and it is also the key basis for inviting national decision-making institutions to increase investment in disaster reduction. In a society where social material production is the driving force of economic development, natural disaster loss assessment is very necessary for * * * affairs, economic exchanges and social activities.
Generalized natural disaster loss assessment can be divided into three types according to the time of disaster events. The first is pre-assessment or predictive assessment before natural disasters occur. The pre-assessment of disaster loss is essentially a predictive work, and its assessment index is a dynamic assessment that changes with time, region, disaster type and social development. The significance of disaster loss pre-assessment is very obvious, which can not only provide reference for national economic development and naturalization, but also provide basis for designing some disaster reduction measures for the existing economic layout.
The second is monitoring and evaluation during the disaster. Monitoring disaster loss assessment is an assessment that can quickly measure the degree of disaster when a disaster occurs. It not only provides a direct basis for disaster command, but also provides a reference for the formulation and overall evaluation of disaster losses, thus giving the decision-making basis for the overall disaster relief strategy in time.
The third is post-disaster field measurement and evaluation. It is an important basis for determining the degree of disaster relief, overall planning and decision-making of post-disaster recovery construction, the actual disaster situation obtained after classification, sampling investigation and statistical calculation of disaster losses, and the basis for finally forming a disaster loss assessment report.
The above three kinds of disaster loss assessment have different meanings and are an important category in the field of disaster prediction research. To do a good job in disaster loss assessment, we must first investigate and analyze the natural geographical environment and social conditions of the assessment area, make statistics on the population and economic development of the assessment area, classify the disaster-resistant efficiency of buildings, engineering facilities and lifeline projects in the assessment area, make scientific predictions on the economic development of the assessment area, and constantly revise and supplement the above information over time to establish the corresponding basic data database of the assessment area.
The evaluation criteria of natural disaster losses should follow the principles of scientificity, comparability and practicality.
The so-called scientific principle means that the evaluation of natural disaster losses should have scientific basis, such as using some methods in mathematical statistics, fuzzy mathematics and prediction theory to scientifically evaluate the natural disaster losses in the evaluation area in space and time domain. The so-called comparability principle means that the standards of natural disaster loss assessment should be unified, and the values of natural disaster loss assessment can be compared or converted in different space and time domains. The so-called practical principle means that the method of natural disaster loss assessment is easy to popularize and the results of natural disaster loss assessment are easy to apply.
3 degree of disaster
Disaster degree is a grading standard to measure the decisive size of natural disaster losses. The determination of disaster degree is based on China's national conditions, mainly from three aspects: social tolerance to natural disasters, natural conditions and corresponding management countermeasures. The disaster grade established by Zongjin Ma and others takes the direct death of population and the loss of social property as the grading standard, and divides the loss of natural disasters into five grades: minor disasters (E grade), minor disasters (D grade), moderate disasters (C grade), major disasters (B grade) and major disasters (A grade).
Economic loss value is comparable economic loss value, and its mathematical expression is:
Comparable economic loss value = σ actual economic loss value × annual inflation index × comparison period (year)
Comparable economic loss value is to classify the loss value of natural disasters in different periods into a specific period.
Compare the price index of the reference period, and then get the absolute amount of social material value loss.
The establishment of the concept of disaster degree links the naturalness and sociality of natural disaster losses with deaths and property losses, and links the intensity of natural disasters with the ability of society to bear disasters. Its significance lies in the establishment of a quantitative standard to describe the classification of natural disaster losses.
4 disaster loss rate
Disaster loss rate is an index to measure the relative amount of natural disaster losses. Reflect the proportion of natural disaster losses to the total economic life and social production in the disaster area. The concept of disaster loss rate is of great significance in disaster classification, disaster rescue and disaster management. The reason for this is the following：
(1) Theoretically speaking, the disaster degree gives the absolute amount of losses caused by natural variation to social wealth, but it cannot fully reflect the proportion of losses caused by disaster events to social wealth and total social production. The latter is precisely the evaluation index to measure the social impact and destructive ability caused by disasters.
Therefore, theoretically, it is necessary to establish an economic index of the destructive capacity of such disasters.
(2) From the perspective of economic development, the degree of disaster can not meet the measurement of disaster loss, so it is necessary to establish an economic index of the destructive ability of this kind of grocery event. In the time domain, with the progress and development of society, the accumulation of total social production and social wealth and the expansion of reproduction, the national economy will continue to grow and the accumulation of social wealth will continue to increase. In space, due to the differences in economic base, population density, resource reserves, scientific and technological level and production capacity in different regions, their social reserves to cope with natural disaster losses, the ability of the whole society to defend against natural disasters, and the self-healing ability of rescue and recovery of production and reproduction after disaster events are also different. Therefore, the losses caused by the same disaster event will reflect the destructive ability and degree of different social wealth in time domain and space domain, which cannot be completely described by the classification of disaster degree alone. Therefore, from the perspective of economic development, it is necessary to establish an economic index of this kind of disaster destructive ability.
(3) Considering the disaster relief project, it should be possible to establish an index to measure the impact of natural disasters on the total social production, social wealth and reproduction capacity. After the disaster, it is of great significance for the external and international community to evaluate the damage degree of the disaster to the social wealth and reproduction capacity of the disaster area, so as to determine the intensity of external and international assistance and funding to the disaster area, investigate and evaluate the self-help and self-healing ability of the disaster area, and evaluate the indirect loss of the disaster and the recovery period of social production and social order in the disaster area.
To sum up, the concept of disaster loss rate should be a scientific, operational and practical economic index for natural disaster loss assessment. In its mathematical definition, the expression of disaster loss rate can be written as:
Disaster loss rate = economical loss/(GDP of the year before the disaster in the affected area × price index)
Among them, the economic losses of disasters should include direct economic losses, indirect losses and disaster relief losses.
Considering the uncertainty of indirect economic loss and disaster relief loss, it is suggested that the direct economic loss of disasters should be regarded as the numerator of the expression of disaster loss rate, which is called direct disaster loss rate, that is, direct disaster loss rate = direct disaster economic loss/(GDP in the year before the disaster occurred in the disaster area × price index). Why did the denominator of disaster loss rate choose "GDP in the year before the disaster occurred in the disaster area× price index"? The reason is that the disaster loss is the negative growth of social production. The occurrence of disaster events will inevitably affect the total social production in the affected areas in that year, so it is no longer possible to compare the degree of damage to social production by disaster events with the total social production in the affected years. The social gross product of the year before the disaster in the disaster-stricken area is selected as a comparative index because it is closest to the social productive capacity of the disaster-stricken area, and then multiplied by the price index, which is equivalent to measuring the damage degree of disaster losses with constant prices.
Economic knowledge tells us that the output value in society is the total production of all social products expressed by workers in the whole social material production field in a certain period of time, and its physical form is all means of production and consumer goods, including social financial income, gross national product and national income. In order to better reflect the loss and damage degree of disaster events to the reproduction capacity, the total amount of final products and services and the newly created value of the whole society in the * * * * function, the expression of disaster loss rate can be written as follows:
Loss rate of fiscal revenue = economical loss/(total fiscal revenue in the year before the disaster in the disaster-stricken areas × price index) Loss rate of gross national product = economical loss/
(Gross National Product × Price Index in the year before the disaster in the disaster-stricken area) National income disaster loss rate = economical loss/(Gross National Product × Price Index in the year before the disaster in the disaster-stricken area) The economic loss caused by the disaster is the loss of social wealth and social production accumulated for many years, and its disaster loss can often be much greater than the social production in the year before the disaster in the disaster-stricken area, especially for huge and serious natural disasters, the value of its disaster loss rate may be. According to the economic development index of China and the statistics of natural economic losses in the 40 years since the founding of the People's Republic of China, corresponding to the concept of disaster degree, the disaster loss rate is also divided into five grades, and its discriminant indicators are shown in Table 2.
Table 2 Classification standard of disaster loss rate
5 discussion
(1) principles of natural disaster loss assessment
Natural disasters are the phenomenon of interaction between natural variation and society. The loss caused by natural disasters is not only related to the intensity of natural variation, but also depends to a great extent on the social and environmental conditions such as the level of economic development, population density and scope of activities at that time. Therefore, the loss of natural disasters is a function of social state.
Doing a good job in natural disaster loss assessment is an important basis for analyzing the benefits of disaster reduction. However, the current disaster loss assessment is far from meeting the requirements of scientific assessment. Especially in the unification of terminology. Basic work such as statistical methods and disaster database indicators is still far from perfect. The scientificity and comparability of natural disaster loss assessment proposed in this paper and practical principles's aim are to establish the knowledge of natural disaster loss assessment.
(2) natural disaster loss assessment index
The loss of natural disasters comes from the accumulated expenditure or negative growth of social wealth and social production.
It includes not only the direct loss and indirect loss of natural disasters, but also the input part of disaster relief and post-disaster recovery after disaster events, which is a very important content neglected in the classification or calculation of disaster losses in the past.
Disaster degree and disaster loss rate are the evaluation indexes of absolute and relative natural disaster losses respectively. The concept of disaster degree established by Zongjin Ma and others takes the number of direct deaths of population and the value of social property losses as two-factor judgment grading standards, and its significance lies in describing the quantitative standard of natural disaster loss classification. The concept of disaster loss rate established in this paper reflects the ratio of natural disaster losses to the total economic life and social production in disaster areas. It is of great significance in disaster management and disaster economics in disaster classification, disaster rescue and disaster insurance. The itemized descriptions of disaster loss rates such as direct disaster loss rate and gross national product disaster loss rate not only provide reference indicators for the classification of statistical methods for natural disaster loss assessment, but also establish indicators for disaster management and disaster economics to judge the degree of natural disaster loss.
How is the direct economic loss calculated after each natural disaster? Houses, transportation facilities, people's property and state-owned infrastructure. Think about it, the place where you live, one day, is affected, and it is all gone. How do you calculate the loss? Involve all aspects of life
How to reduce the loss of natural disasters
Prevent disasters from happening. Timely monitoring and forecasting. Conduct disaster research. Disaster prevention engineering construction, such as dike protection, improving the seismic grade of buildings, etc.
When a disaster happens, deal with it correctly. Need to train in advance.
Timely disaster relief, you can contact international rescue.
Buy insurance,
Strengthen education and raise residents' awareness of disaster prevention and reduction.
That's all I thought of,
Disaster indicators of natural disasters include affected area, affected area, crop failure area, economic loss and so on. What could a natural disaster be? Flood disaster seems to be more consistent.
Is the answer unique? It seems that many disasters are justified, such as mudslides, hail, snowstorms and volcanic eruptions.
How much does meteorological disaster loss account for the total loss of all natural disasters? We mainly use meteorological models developed by the European Union Meteorological Center, including forecasting models and disaster models. The pre-clearing accuracy of the forecast model in the European Union is about 90%, which is the same as that in the United States, while the pre-clearing accuracy of the model developed in China is about 80%. The accuracy before rain is between 50% and 60%, and the EU and the United States can reach about 70%. The evaluation model of meteorological disaster loss is not perfect, and it is still in the stage of continuous research.
Who suffers more from "natural disasters" than "wars"? There are wars and natural disasters. For example, World War II, such as the Black Death, is unparalleled.
How to write the economic loss report of flood disaster in enterprises. List the lost materials, quantity, unit price and amount, write a report after counting the total amount, and give suggestions on how to deal with the losses caused by natural disasters.
What is the national compensation for natural disasters?