Study On Emergency Material Selection Reserve And Allocation Schema For River Chemical Spills

With an increase in industrialization and urbanization in China,the rise of the frequency and intensity of river chemical spills caused by discharge pollutant without permission,production accidents and natural disas ters,highlight the need to improve our capabilities to minimize the damage in a quick response.In order to solve the main technical problems of environmental emergency management,environmental risk assessment,emergency material selection,emergency material reserve layout planning and emergency material allocation are studied to enhace the environmental emergency response ability.According to multiple critera decision making and fuzzy theory,an environmental risk assessment method and emergency material selection framework based on dynamic fuzzy GRA are developed to evaluate environmental risk level and probability and selection optimal emergency material for emergency disposal scheme.The environmental risk assessment method is applied to environmenta l emergency management system in Jiangsu province,China.The result shows that probability of river chemical spills is 0.00246.And the percentages of chemical leaks heavy metal pollutions and oil spills leading to the river chemical spills account for 54.40%,20.28%,25.32%,respectively.Dynamic fuzzy GRA method is then applied in a historical case study to evaluate emergency disposal scheme and select emergency material in emergency arsenic pollution considering different emergency disposal stages under two scenarios associated with different arsenic levels.The result shows that Activated alumina is the optimal material selection for the low degree of arsenic concentration.And the emergency material synthetic combined with FeSO4 and Activated alumina can effectively mitigate the concentration of arsenic with a high degree.Environmental risk assessment and emergency material selection results can provide scientific references and effective supports for emergency material reserve layout planning and emergency material allocation decision making.According to continuous location theory and discrete location theory,a n emergency material reserve layout planning framework based on continuousdiscrete location theory is developed for emergency material reserve layout planning to identify material warehouse locations and emergency material reserve schemes with a lack of existing material warehouse condition in order to cope with potential river chemical spills.First,decision alternatives are generated using Hierarchical clustering analysis-improved center of gravity(HCA-ICG)model to identify newly-built emergency material warehouses to ensure risk sources can be covered by an effective emergency material warehouse.Second,emergency material reserve planning is obtained using material warehouse location-emergency material allocation(MWL-EMA)model to make emergency materials can be prepared in a cost-effective manner.The planning framework is then applied to environmental emergency management system in Jiangsu province,China.And the results put forward an optimal location scheme and identified 5 sites for I level emergency material warehouses and 5 sites for II level emergency material warehouses,and also an optimal emergency material reserve scheme.According to multiple critera decision making and multi-objective programming method,an emergency material warehouse location planning framework based on the aboved theory is developed for emergency material warehouse location evaluation and selection to identify the optimal emergency material warehouse locations with a sufficient existing material warehouse condition in order to cope with potential river chemical spills.First,a fuzzy TOPSIS method is applied to determine relative closeness of the feasible location alternatives based on environmental impact assessment of risk sources.Second,a multi-objective optimization model is developed to obtain optimal emergency material warehouse location schemes guaranteeing all the potential risk sources can be covered by an effective emergency material warehouse.The planning framework is then applied to environmental emergency management system in Jiangsu province,China.And the results put forward an optimal location scheme and identified the best 5 emergency material warehouses with the objective of minimum rescue points and maximum integrative rescue abilities.The planning results can provide scientific references and effective supports for emergency material allocation decision making.Two emergency material scheduling schemas are proposed for emergency material allocation in order to cope with chemical contingency spills.For emergency material allocation schema with single-demand point and multi-supportive center,an emergency material allocation model under time-varying supply-demand constraint and optimization algorithm is developed to identify practical emergency response time and obtain emergency material scheduling schemes.For emergency material allocation schema with multi-demand point and multi-supportive center,an emergency material allocation model with two objectives of the minimum rescue time and the minimum number of supportive centers is developed to coordinate both allocation and scheduling of the emergency materials.Meanwhile,an improved genetic algorithm for emergency material allocation model is proposed to identify the emergency material scheduling schemes.The two schemas are then applied to a computational experiment for environmental emergency management system in Jiangsu province,Chi na.The developed method not only could satisfy the requirements of the emergency rescue for chemical contingency spills,but also help decision makers adjust appropriate emergency material scheduling schemes in different situations.The planning results can provide scientific and effective technical supports for environmental emergency management and pollution prevention and control.