(Hebei Geological Environment Monitoring Station, Shijiazhuang, 05002 1)

This paper expounds the necessity of economic benefit evaluation of debris flow disaster prevention measures, establishes the index system of benefit evaluation of debris flow disaster prevention measures, and systematically puts forward the evaluation method and model.

Keywords:: Economic Benefit Evaluation of Debris Flow Disaster Prevention and Control

Debris flow is one of the sudden geological disasters in mountainous areas of Hebei Province, with a wide area and great harm. In recent ten years, the area, scale, frequency and harm of debris flow have been increasing, which has become an obstacle to the economic development in mountainous areas of Hebei Province. At present, with the deepening of the research on the prevention and control methods of debris flow disasters, various prevention and control measures are constantly emerging. In order to ensure that investment prevention measures have more implementation benefits, this paper studies the economic benefit evaluation method of debris flow prevention measures to solve the economic evaluation problem of debris flow prevention measures and provide guidance for debris flow prevention decision-making.

1 research overview at home and abroad and the significance of carrying out economic benefit evaluation of debris flow disaster prevention and control

1. 1 Review of domestic and foreign research

A summary of foreign research on 1. 1. 1

Before the 1960s, the study of natural disasters was mainly limited to the study of disaster mechanism and prediction, focusing on the investigation of disaster formation conditions and activity process. After 1970s, with the sharp increase of natural disasters, the prevention and control of disasters has been promoted to an unprecedented height. In some developed countries, first of all, the field of disaster research has been broadened, and while continuing to study disaster mechanism in depth, risk assessment has begun.

In 1980s, more and more attention was paid to the study of various natural disasters. The results of benefit evaluation of disaster prevention and control are constantly emerging.

1. 1.2 domestic research summary

China has always attached importance to disaster reduction. In order to effectively prevent and rescue disasters, special emphasis has been placed on strengthening disaster investigation and evaluation and benefit evaluation of disaster prevention measures, and remarkable results have been achieved. However, the early research work was mainly limited to the statistical description of disaster events and disaster losses. At the end of 1970s, disaster assessment research began to rise and flourish. A number of research contents have reached the international advanced level, and the results not only support the cause of disaster reduction in China, but also promote the improvement of the international research level of disaster prevention and control benefit evaluation. But so far, the research on the evaluation of disaster prevention benefit has not yet formed an independent discipline system. In addition, the research level of each province (city, district) is not the same. The research level in Sichuan, Hubei, Yunnan and other provinces is relatively high, while the research in Hebei Province is almost blank, so it is urgent to strengthen the investment in disaster prevention and control benefit evaluation research.

1. 1.3 Significance of economic benefit evaluation

Debris flow disaster will not only cause casualties, but also directly or indirectly lose social wealth and natural resources and destroy social production and living infrastructure. Therefore, most debris flow disaster prevention and control projects shoulder the tasks and construction goals of protecting personnel safety, social wealth and natural resources, protecting and improving social production and reproduction conditions, providing and increasing social production capacity and improving economic benefits. Therefore, economic benefit evaluation has become one of the main conditions and decision-making basis for comparing the priorities of projects and the advantages and disadvantages of schemes.

Debris flow disaster in Hebei province is serious and needs to be treated urgently. However, the government's financial resources can be used for investment in debris flow prevention and control projects, which requires that the prevention and control of debris flow disasters must follow the principles stipulated in the Regulations on the Prevention and Control of Geological Disasters and strive to implement disaster control funds. In addition to protecting personnel safety, the economic benefit of governance is an important issue that needs attention.

The economic benefits are reflected in the design scheme. Therefore, carrying out economic benefit evaluation can urge the planners of debris flow prevention projects to improve their design ideas and increase the technical and economic content of the schemes, which not only increases their social production connotation, but also urges decision makers to attach great importance to the decision-making role of economic benefits in project establishment and scheme comparison, and make full use of the evaluation results as the basis for decision-making. Realize the "economic rationality" of project management.

2 principles of economic benefit evaluation

2. 1 Ensure objectivity and comparability of evaluation.

The purpose of evaluating the economic benefits of debris flow prevention measures is to truly grasp the economic benefits of debris flow prevention measures and serve decision-making, so the evaluation indicators should be comprehensive, reliable and objective to prevent subjectivity.

Whether the benefit is good or not must be reflected by comparison, and the evaluation model should reflect the level of benefit and the effect of prevention and control measures more intuitively.

2.2 Systematic principle of evaluation indicators

The occurrence of debris flow disaster is the result of the comprehensive action of many factors. The evaluation index requirements include all aspects involved in the prevention and control objectives, and there should be appropriate evaluation indexes for qualitative problems to ensure that the evaluation does not appear one-sidedness.

2.3 highlight the key principles of indicators

Because the purpose of measures varies with time or region, the evaluation process should highlight the corresponding key evaluation indicators to reflect the priority of debris flow prevention measures.

3 Economic benefit evaluation model

3. 1 index system for evaluating the economic benefits of debris flow prevention and control

The prevention and control of debris flow disaster has become the basic work of mountain construction. Debris flow prevention measures have different benefits due to different prevention priorities, investment differences and production conditions. Therefore, based on the principle of comprehensiveness, comprehensiveness and emphasis, the following economic benefit evaluation index system is proposed (see figure 1).

Figure 1 Economic benefit evaluation index system

As can be seen from Figure 1, the economic benefit evaluation of debris flow prevention includes three parts: direct economic benefit, indirect economic benefit and prevention investment.

The direct economic benefits include three parts: wealth protection, wealth creation and wealth appreciation after the treatment of debris flow dangerous areas or threatened areas.

Indirect economic benefits, like direct economic benefits, include wealth protection, wealth creation and wealth appreciation, but these benefits all occur outside the control area, often in the downstream area where debris flow ditches flow into the main river. Prevention and control investment refers to the investment and operating expenses required for prevention and control measures.

3.2 Numerical determination of economic benefit indicators

When making economic benefit statistics, the unit is 654.38+10,000 yuan, and all wealth values should be converted into RMB according to the unit price at the time of evaluation.

The statistical service life of economic benefits is generally the service life of prevention and control engineering design.

When the output is converted into monetary value, the unit price should be the unit price at the time of evaluation, and the current price in the evaluation year should be adopted, including the engineering cost when building the debris flow prevention project, so that the investment and governance of the prevention project can be regarded as the output of economic benefits and the same value index can be adopted.

If the benefit evaluation period is long, such as 50 years or even 100 years, it is difficult to predict the future crop output or processing industry output value now, so it will be calculated according to the output or output value of the previous year or the average value of the output or output value of the previous five years, but the unit price of the five-year output is the unit price of the evaluation year.

Through the above methods, the net economic benefits in different periods and years are transformed into unified standard values, which lays the foundation for the mathematical calculation of economic benefit evaluation.

3.3 Mathematical methods of economic benefit evaluation

Economic benefit evaluation adopts calculation methods such as net benefit, benefit-cost ratio and investment payback period.

3.3. 1 calculation formula

Net benefit P = benefit-(investment+annual operating expenses)

Benefit-cost ratio (BCR)

The expression of investment payback period t is:

static electricity

dynamic

In which: k- total investment;

I- annual interest rate;

B—— the annual average benefit of the project, which is called the total benefit;

C- the average annual operating cost of the project.

data source

Investment: It mainly includes three parts: state investment, local fund-raising and investment capital reduction.

Benefit: Direct economic benefit after comprehensive disaster prevention and control.

Annual operating expenses: mainly including investment management expenses, in addition to taxes and other expenses. Generally, the annual operating cost is 2% ~ 5% of the total investment.

Payback period of investment: calculated according to dynamic and static conditions.

3.4 Comprehensive economic benefit evaluation

Comprehensive economic benefits are evaluated by insurance ratio. Its expression is:

Insurance ratio = prevention and control investment/value of protected object (present value)

3.4. 1 prevention and control input

All investments related to debris flow prevention and control should be included, and the maintenance fee after the completion of the project should be included in the prevention and control investment, and the initial investment should not be used as the prevention and control investment. Its composition and expression are as follows:

Essays on Geology, Environment and Economics. Series 2

Where: C is input for prevention and control; Ct is the maintenance fee of the T-year project; N is the service life of the project, which is the same as the service life of the project; (1+i)-t is the discount factor for t years.

3.4.2 Value of protected objects

Value of protected objects: including fixed GDP and gross national product of protected objects. The total value of fixed assets of the protected object adopts the net loss value, and the gross national product adopts the multi-year cumulative value with the remaining production years of the protected object or the years of debris flow disaster prevention and control projects as the calculation period.

The calculation of the value of the protected object is divided into two situations:

(1) The value composition of the protected object in the case that it cannot be repaired after disaster loss:

Bp=(Bg-Bc)+Bs

Where: Bp is the sum of the cumulative present value of the protected object; Bg is the present value of the total fixed assets to be protected; Bc is the recoverable residual value of fixed assets; (Bg-Bc) is the value of fixed assets actually protected by the project; Bs is the sum of the present value of the gross national product of each year in the remaining production period (that is, from the time of disaster prediction to the time when the production function of the protected object is normally lost).

(2) The value of the protected object includes:

Bp=2Bg+Bs

Where: the meanings of Bp and Bg are the same as those in (1), and Bs is the loss value of the gross national product during the shutdown period (cumulative years in the calculation period).

Through the above analysis, according to the different degree of debris flow damage, the value composition of the protected object is also different, so the calculation of insurance ratio is also different. Therefore, when evaluating the economic benefits of debris flow prevention measures with insurance ratio, we must first understand what the value composition of the protected object is, and then we can make a scientific and objective evaluation.

4. Application of economic benefit evaluation in optimal control scheme

If the engineering benefits of the control scheme can be successfully obtained, then the economic indicators such as benefit-cost ratio, net benefit and payback period of each project can be obtained through dynamic economic analysis according to the engineering benefits, investment and operating costs of the debris flow prevention project, so as to make economic evaluation. For example, the benefit-cost ratio can intuitively express the economic benefits of debris flow prevention and control in the form of currency ratio. The evaluation criteria are determined according to the proportion. Only when the ratio is greater than 1 can economic benefits be generated, and the greater the ratio, the better the economic benefits of prevention and control. The insurance proportion can also be expressed in an intuitive proportion form. Under the premise of meeting the established social and ecological benefits, the smaller the insurance proportion, the better. However, due to the losses caused by debris flow disasters and the benefits of prevention and control projects, it is often difficult to quantify in many cases, so it is difficult to calculate various economic benefits. Therefore, in some cases, according to the advantages and disadvantages of various schemes, sometimes the scheme can be selected through analysis and comparison. When it is really difficult to quantify the preventive benefits of disaster prevention projects correctly, but it is known that the benefits of each control scheme are basically equal and can generally meet the requirements of disaster prevention, the method of minimizing the total cost or annual cost can be used to find the optimal scheme. This evaluation method is particularly feasible for the selection of debris flow prevention schemes in Hebei Province.

5 conclusion

It is an urgent task for the prevention and control of geological disasters to strengthen scientific research, reduce blind investment, adopt the most economical, reasonable and effective scheme and obtain the best benefits of comprehensive prevention and control. Based on the study of debris flow prevention and control measures in Hebei Province, the evaluation index system of economic benefits of debris flow prevention and control is established, and the method and evaluation model of evaluating economic benefits of debris flow prevention and control measures with net benefit, benefit-cost ratio, investment payback period and insurance ratio are summarized. However, there are still many problems in the economic benefit evaluation of debris flow prevention measures, which need further discussion and research. It is expected that relevant experts will make joint efforts to explore a more reasonable calculation method in a short time to meet the needs of engineering design.

refer to

[1] Yan Chonglun et al. Basic Knowledge and Application of Feasibility Study of Construction Projects, Beijing: Electronic Industry Press, 1985.

Sean, etc. Theory and practice of geological hazard assessment. Beijing: Geological Publishing House, 1998.

[3] Sean et al. Economics of Geological Disasters. Shijiazhuang: Hebei People's Publishing House, 2002.

[4] Tang, et al. Social benefit evaluation and index system of debris flow. Journal of Soil and Water Conservation, 1994 (3): 64 ~ 68.