Abstract: my country occupies a very important position in water conservancy projects, and the growing economy requires huge water conservancy support. However, the current situation of water conservancy projects is not optimistic, and there are many problems. As a result, the risks of water conservancy projects are getting bigger and bigger, which has brought about a series of serious consequences, including casualties, heavy economic losses, environmental damage and serious pollution. It is not only necessary to strengthen the quality supervision of water conservancy projects to reduce the probability of risks. It is also necessary to analyze the causes of each incident to reduce the harm of risks and minimize losses.
Keywords: Risk analysis and water conservancy engineering review
CLC classification number: TV21 Document identification code: A Article number: 1007-3973 (2012) 007-011-02
1 Introduction
Risk is inseparable from the uncertainty of events. The current situation of the event, the process of the event, the probability of risk occurrence and the consequences are closely connected with the uncertainty of the event. Any one of the three factors will have an important impact on the event. Therefore, when we analyze the risks of water conservancy projects, we mainly focus on a series of issues such as casualties, economic losses, and environmental damage from a systems engineering perspective, that is, an economic perspective (including investment, safety, and damage). Countries such as the Netherlands have a further explanation of risk, that is, the probability of a project accident multiplied by its consequences, that is, the expected loss value, which is judged by comparing the economic investment required to improve system safety with the reduced expected loss. The magnitude of the risk. Risks in China are mainly expressed as whether it is reliable and how reliable it is, that is, the probability of system failure caused by a load greater than the system's carrying capacity. In recent years, water conservancy project safety managers have conducted many studies on water conservancy project risks, especially analyzing issues such as dam failures. Unfortunately, our country has not formed its own system in terms of risk calculation, rarely takes risk rates into account, and mostly uses crash consequence evaluations from other countries. Therefore, this article mainly studies and comments on water conservancy project risks from the various causes of risk occurrence.
In 1971, Yen discussed the feasibility of water conservancy systems. Subsequently, the application of risk analysis systems has gradually become more widespread, such as in reservoirs, dams, embankments, water resources, water environment, etc. Nowadays, qualitative and quantitative analysis is the main performance of water conservancy project risk analysis. Risk analysis and processing is a risk analysis conclusion drawn by combining the collected data, extrapolation and subjective analysis with mathematical statistics, analytic hierarchy process, etc. Therefore, the author believes that the risk analysis of water conservancy projects should be carried out from the aspects of system engineering construction, economic income, casualties, environmental damage, etc.
2. Current status of water conservancy projects
my country is rich in water resources and has very developed water conservancy projects (the Three Gorges Dam has an important position in the world). Water conservancy construction is closely related to all aspects of national construction. . However, there are many problems in water conservancy projects in our country, such as unreasonable distribution of water resources, water pollution, and high risks of water conservancy projects. Especially in terms of water conservancy project risks, the probability of risk occurrence is high, and a series of problems caused by the risk are even more serious.
The main reasons leading to these problems are:
(1) The investment in the project is small, low-cost and excessive construction is used, that is, the worst materials are used, and unqualified technical personnel are used, etc. to build, so the project will not achieve good quality.
(2) Making a fuss out of a molehill. A project that originally cost hundreds of thousands would cost more than one million to complete, thus wasting a lot of manpower, financial and material resources.
(3) Lack of industry protection. Highways, railways and other industries have special protection measures, but water conservancy projects do not. Especially when bidding, the winning bidders are all large-scale construction industries. They feel that water conservancy projects The profit is small and the quality of the project is not taken seriously, which is not conducive to the construction of the project.
(4) Brain drain. Due to the unsatisfactory income of water conservancy project staff, many talents have changed careers, resulting in a shortage of technical personnel, which will inevitably reduce the quality of water conservancy projects.
(5) The construction period is politicized. In order to pursue political significance, standards are lowered and the construction period is shortened. This is a problem that should not occur in water conservancy projects. It can be seen that there are still many shortcomings in my country's water conservancy projects, and there are still many areas worthy of improvement.
3 Risks and Analysis of Water Conservancy Projects
Any project has certain risks, and the risk of water conservancy projects is slightly greater than that of other projects. Risk refers to the many uncertainties in expected consequences. Factors such as the amount of investment, project progress, quality and safety affect project goals. Each of these items includes three levels of factors: (1) Risk exists at all times. Any project will have surprises when it comes to achieving its goals. (2) Risk events are affected by a series of poor quality, various changes in the environment, and people's limited ability to predict, and there are many uncertainties. (3) The consequences of risks are also difficult to predict. Due to the constraints of various factors, it is difficult for people to estimate the extent of the damage and the losses caused. This is what we call risks with a lot of uncertainty. In addition, water conservancy projects require large investments, take a long time, have complex internal structures, involve a large number of people involved in the project, and have high risks, which are the basic characteristics of water conservancy projects. This leads to various risks and increases the probability of risk occurrence. Therefore, analyzing and researching the occurrence of risks is conducive to accumulating experience and improving scientificity, thereby reducing the occurrence of risks. It mainly analyzes environmental element risks, project system structure risks, risks generated by project actors and other risks, and makes a comprehensive summary. This requires us to use scientific methods for analysis, generally from directional to quantitative, from subjective analysis based on experience to objective analysis that speaks with facts and truth, taking into account a wider range of uncertain factors and making predictions more accurate. . We know that although water conservancy project risk analysis has made great progress, there are still some shortcomings, which are reflected in:
(1) Most of the analyzed results are based on individual case analysis, and only project analysis The risk rate has not been analyzed and evaluated in depth, which makes the analysis results limited and one-sided.
(2) Logical analysis itself has some shortcomings. It focuses on one-sided analysis of one risk and simply describes other risks, which is not conducive to the improvement of risk analysis.
For example, in 2011, some provinces in my country encountered a rare drought in half a century, and subsequent disasters such as droughts and floods. The main purpose here is to analyze the changes in the weather environment, which have led to an increase in precipitation. The resulting risk issues can be seen from the analysis of the imperfections of my country's water conservancy projects and other risks. When analyzing the risks of water conservancy projects, we must:
(1) Use a comprehensive method to analyze, from various perspectives analysis to improve the accuracy of analysis results.
(2) Use some advanced foreign analysis methods to improve your own analysis level, thereby improving the results of risk analysis.
(3) Carry out some special studies on water conservancy project risks and conduct various seminars to improve their scientific nature.
(4) Based on the analysis of the causes and results of the accident, increase vigilance, strengthen management, and reduce risk hazards.
For example, breaches, diversions and interruptions are the most important problems currently existing in the Yellow River. In some rivers in the lower reaches of the Yellow River, starting from Zhengzhou, the riverbed is much higher than the two banks. Therefore, "hanging rivers on the ground" appeared. The lives and property of people on both sides of the Taiwan Strait are under serious threat. This requires the construction of water conservancy projects to protect river embankments. Since liberation, the embankment has been raised several times to reduce the risks of water conservancy projects. The continuous heightening of river embankments has caused continuous breaches, affecting the lives of people on both sides of the Yellow River and the ecological environment along the way. In recent years, flow interruptions have occurred in the lower reaches of the Yellow River. In addition to direct impacts on industrial and agricultural production and people's lives in the lower reaches of the Yellow River, flow interruptions have also increased a large amount of silt, and the risk of river embankments has also continued to increase. In response to this problem, Chinese experts Chen Xinmin, Xia Jia, Luo Guoyu and others have conducted corresponding research. In the 10th issue of "Journal of Hydraulic Engineering" in 2009, they systematically analyzed the risks of water conservancy projects from multiple angles and drew on some foreign experience. Find some solutions to reduce the risk.
4 Impact of Water Conservancy Project Risks
Since water conservancy projects are highly risky and contain many uncertain factors, it is also difficult to predict them scientifically. Therefore, the economic environment It will also have a huge impact. Mainly manifested in four aspects:
(1) Casualties due to lack of attention to employee safety, incomplete safety facilities and poor sense of responsibility of the project leader.
(2) A lot of human, financial and material resources are consumed. Most projects cut corners, use the worst raw materials, shorten the construction period, only focus on temporary use, and ignore the long-term use value of the project. In this way This requires constant maintenance of the project, thus increasing its construction cost. Foreign water conservancy projects attach great importance to their long-term use value. Many of them are still in good condition after being used for a century. This is also the biggest difference between Chinese and foreigners in engineering construction.
(3) Environmental pollution is serious. All day long construction projects emit a lot of dust and smoke, polluting the air. Large amounts of wastewater are discharged and water pollution is serious.
(4) The ecological environment has been severely damaged, and water conservancy projects have reduced the diversity of rivers, thereby reducing the diversity of biota.
5 Conclusion
In short, there are many shortcomings in water conservancy projects in our country and around the world, and the possibility of risks is also very high, and a series of serious consequences are even more disturbing. incredible. Therefore, only by strengthening the understanding of risks, continuously improving engineering construction science and technology, and increasing research on water conservancy project risk analysis can we reduce the harm caused by water conservancy project risks.
References:
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