Assessment of safety and risk of flooding of urban industrial territories: expert-analytical method

Summary

The main provisions of the expert-analytical method for assessing the risk of hazardous processes are stated; the method formed the basis for the development of a number of methodological recommendations and state standards. On the basis of this method, a technique is proposed for assessing the safety and risk of one of the dangerous natural-technogenic processes – flooding of urban industrial territories. The main factors of the harmful impact of this process on the structures located in such territories are indicated. It is shown how risks and damages from flooding of urban industrial territories can be estimated on the basis of the general methodological approach to assessing risks from hazardous techno-natural processes. As a result, criteria for safety and risk of flooding were obtained and a mechanism for assessing the risk of flooding was developed. The features of the assessment of the risk from flooding of urban industrial territories at the federal, regional and local levels are revealed.

Key words

underflooding , safety , risk , опасность , vulnerability , expert-analytical methoд , damage , urban industrial territory , harmful impact , dose of harmful impact , федеральный уровень , regional level , local level

Designing looped wastewater systems with bypass sewers

Summary

The aspects of simulating fluid movement in wastewater disposal systems of looped structure are considered. It is shown that separate bypass sewers can operate both with gravity and pressure flows. Meanwhile preliminary studying the flow hydraulic parameters is required. In the process of hydraulic network designing potential threat of wastewater underflooding and surface spilling have to be analyzed first. It is suggested to determine wastewater flow rates that are distributed among separate bypass sewers on the basis of energy and mass-conservation equations (similar to Kirchhoff’s laws). General design procedure is proposed and examples of designing wastewater disposal systems with bypass network sections for the entire range of possible fluid movement modes including emergency situations are presented. The aspects of improving wastewater system integrity by introducing looped structures are considered. For the operators the design procedure can be helpful in centralized control systems in case of isolating accident failures or optimizing flow modes. In case of automatic flow distribution the design procedure provides for advance estimating control action on gate valves and simulating the aftereffect of their opening or closing. Looped structures can be used in the process of wastewater disposal system reconstruction and development; whereas the developed procedure of hydraulic designing will allow the design engineers to substantiate their parameters.

Key words

water disposal system , underflooding , bypass sewer , pressure and gravity flow

Numerical Simulation for Substantiation of the Engineering Protection System in the City of Kazan

Summary

It is told about the process of creating a software package for numerical simulation of the drainage system in the city of Kazan. The calculations to determine the optimal mode of its operation are presented. The problem of optimizing the operating mode of pumping stations is formalized and presented as a problem of multicriterion optimization: reducing the potential damage as a result of underflooding at minimization of energy costs. The decision has been found with the help of an evolutional algorithm. On the basis of calculations carried out the recommendations for optimization of the pumping stations operation mode in the city of Kazan making it possible to reduce expenditures for operation of the engineering protection system for preservation of urban territories from underflooding have been given.

Key words

ground water , underflooding , drainage , numerical simulation , software package , minimization of damage , evolutional algorithm , optimization