Oil Spill Response Operations Research Articles

Evolutionary Approach to Optimal Oil Skimmer Assignment for Oil Spill Response: A Case Study.

We propose a genetic algorithm for optimizing oil skimmer assignments, introducing a tailored repair operation for constrained assignments. Methods essentially involve simulation-based evaluation to ensure adherence to South Korea's regulations. Results show that the optimized assignments, compared to current ones, reduced work time on average and led to a significant reduction in total skimmer capacity. Additionally, we present a deep neural network-based surrogate model, greatly enhancing efficiency compared to simulation-based optimization. Addressing inefficiencies in mobilizing locations that store oil skimmers, further optimization aimed to minimize mobilized locations and was validated through scenario-based simulations resembling actual situations. Based on major oil spills in South Korea, this strategy significantly reduced work time and required locations. These findings demonstrate the effectiveness of the proposed genetic algorithm and mobilized location minimization strategy in enhancing oil spill response operations.

Evaluation of surfactant-aided polycyclic aromatic hydrocarbon biodegradation by molecular docking and molecular dynamic simulation in the marine environment

Marine oil spills directly cause polycyclic aromatic hydrocarbons (PAHs) pollution and affect marine organisms due to their toxic property. Chemical and bio-based dispersants composed of surfactants and solvents are considered effective oil spill-treating agents. Dispersants enhance oil biodegradation in the marine environment by rapidly increasing their solubility in the water column. However, the effect of dispersants, especially surfactants, on PAHs degradation by enzymes produced by microorganisms has not been studied at the molecular level. The role of the cytochrome P450 (CYP) enzyme in converting contaminants into reactive metabolites during the biodegradation process has been evidenced, but the activity in the presence of surfactants is still ambiguous. Thus, this study focused on the evaluation of the impact of chemical and bio-surfactants (i.e., Tween 80 (TWE) and Surfactin (SUC)) on the biodegradation of naphthalene (NAP), chrysene (CHR), and pyrene (PYR), the representative components of PAHs, with CYP enzyme from microalgae Parachlorella kessleri using molecular docking and molecular dynamics (MD) simulation. The molecular docking analysis revealed that PAHs bound to residues at the CYP active site through hydrophobic interactions for biodegradation. The MD simulation showed that the surfactant addition changed the enzyme conformation in the CYP-PAH complexes to provide more interactions between the enzyme and PAHs. This led to an increase in the enzyme's capability to degrade PAHs. Binding free energy (ΔG‌‌Bind) calculations confirmed that surfactant treatment could enhance PAHs degradation by the enzyme. The SUC gave a better result on NAP and PYR biodegradation based on ΔG‌‌Bind, while TWE facilitated the biodegradation of CHR. The research outputs could greatly facilitate evaluating the behaviors of oil spill-treating agents and oil spill response operations in the marine environment.

A Mesh Convergence Study on 2-D Air Bubble Barrier Simulation with Mean of Inlet Static Pressure and Horizontal Surface Velocity

Timing is vital for oil spill response operations. However, deployment of the traditional response equipment, unfortunately, takes much more time. Therefore, innovative solutions are needed to minimize time losses. One of these innovative solutions is the air bubble barrier. Air bubble barrier creates a barrier to anything floating in the water, especially keeping the floating oil and petroleum in the area where it is spilled. Computational Fluid Dynamics simulation has grown in importance as a resource for air bubble barrier studies in recent years. Despite the extraordinary success of Reynolds Averaged Navier-Stoke applications on air bubble barriers, just a few studies concentrate on mesh sensitivity, one of the most fundamental issues with CFD methods. The main purpose of this study is to perform a mesh convergence study by simulating an air bubble barrier in the Simcenter STAR CCM+ software. In this context, in this simulation, a 2D numerical model is considered. The mesh convergence study has been performed by calculating the aperture inlet mean static pressure and the mean horizontal surface velocity. As a result, it is evident that the mesh base size and number of elements in mesh in case 10 can be employed to maintain the solution time-optimal state in the upcoming numerical simulations on the 2D and 3D air bubble barrier. Case 10 represents the mesh base size of 0.015 and the number of elements in mesh of 99042. Findings from this parametric study will be incorporated as mesh control rules into the subsequent 2D and 3D simulations of the air bubble barrier.

A Comprehensive Review of Canadian Marine Oil Spill Response System through the Lens of Decanting Regulations and Practices

Marine oil spill response operations could generate a large volume of liquid oily wastes (e.g., emulsified oil, non-emulsified oil, and wastewater) that can be up to 30 to 40 times greater than the original volume of spilled oil. Oil decanting technologies are used globally for recovering spilled oil and handling liquid wastes. Canada follows the standards set out in the MARPOL 73/78 Annex 1 International regulations in most areas, with more strict discharge requirements in certain locations. For instance, inland waters discharge should not exceed 5 ppm, and in special areas, such as the Great Lakes, the discharge standard is under 0 ppm. In the event of an oil spill, decanted seawater should be barged to shore for disposal, which significantly constrains the response capacity and efficiency of oil recovery by skimmers due to limited temporary storage space in barges and the long time and high cost of transportation. This has become one of the greatest challenges the Canadian governments and oil spill response industries are facing in Canada. Moreover, when the spill response team decides that decanting is an appropriate way to handle the spilled oil, the approval process may take a long time, which negatively impacts the spill that has already occurred. Moreover, Canada uses a 10,000-tonne planning standard for oil spill preparedness, whereas the United States uses a worst-case scenario, and Europe uses a 60,000 m3 planning standard. The existing planning threshold in Canada can cause the country to be not fully prepared when it comes to responding to a very large oil spill if one should occur. This study conducted a comprehensive review of the current Canadian oil spill response system and framework, regulations, roles and responsibilities of federal and provincial governments, existing decanting capabilities, and capacities of Canadian oil spill responders. More importantly, this study identified the gaps in the current oil spill response system and regulatory and technological barriers to oil decanting. Marine oil decanting regulations and practices in the US and selected European countries have also been reviewed to support addressing the challenges and improving the Canadian experience. It is expected that this study would help the stakeholders and professionals to better understand the oil spill response system and oil decanting status quo in Canada and facilitate Canadian governments and industries to better address the challenges in oil spill regulations and practices.

Drone Equipment and Configuration for Crude Oil Spill Detection in Water

Purpose: The objectives of this article was to outline the various equipment and configuration of drones which can be used to detect and support oil spill response in water. The study aimed at identify the type of sensors that can be mounted on drones for effective crude oil spill detection in water.
 Methodology: A systematic review of past articles on drones in disaster management was done. In this article, various parts of drone and configuration was tested. Sensors capable of detecting crude oil in the visible, infra-red, near infrared, laser fluoro-sensor were elaborated.
 Findings: A drone can properly be used for oil spill response operations. Appropriate sensors mounted on the drone can detect oil spill in water and can also access locations which are not readily accessible to large ships and other aerial patrol platform. The limitation of drones is the payload capability and its inability to operate well in windy weather.
 Recommendation: Since data collection with drone are faster, cheaper and easier during an oil spill response operations, it is highly recommended to mount the suitable sensor capable of detecting oil sheen even during nighttime operations.

A System Dynamics Modeling Approach for Estimation of Oily Waste Generation From Marine Oil Spill Response: A Case Study of an Oil Spill in Central Coast of British Columbia

The understanding of waste generation is of critical importance for effective oily waste management in marine oil spill response operation. A system dynamics model was developed in this study to estimate the quantity of oily waste generated from marine oil spill response operations. Various aspects were considered, including weather conditions, spilled oil volume and characteristics, response time, and response methods. The types of oily waste include recovered oil, oily water, oily sorbents, oily personal protection equipment, and oily debris. The model was validated using data collected from an actual oil spill incident in British Columbia, Canada. The comparison of model estimation and observed results showed an average prediction accuracy of 86%. Sensitivity analysis was conducted to examine the impacts of two modeling parameters, including response arrival time and sorbent booms amount. Results of a case study indicated that initiation of response operations 5-h earlier could increased oil recovery by 26%. Furthermore, sensitivity analysis highlighted a 45% overuse of sorbents which resulted in the generation of unnecessary oily solid waste. Response surface methodology (RSM) analysis was applied to analyze the interaction effect of model parameters on model outputs. Results showed a significant interaction between sea temperature and response arrival time on recovered oil and between sorbent boom weight and sorbent booms usage rate on solid waste. The developed model can provide an effective tool for informed waste management decision-making related to marine oil spill response operations.

A Cluster-Based Technique for Identifying and Grouping Oily Waste Types Generated From Marine Oil Spill Response Operations

In the event of a marine oil spill and its subsequent response operations, different types of oily wastes are generated in large quantities, and their management is a significant challenge that oil spill responders face. The goal of this study is to develop a comprehensive pattern recognition modeling framework for deriving and grouping a set of unique clusters that separate different types of oily wastes from each other. The main idea is to group oily wastes based on their unique characteristics, such as the percentage of oil, percentage of water, percentage of mineral matter, and percentage of organic matter. Each cluster has a relatively homogeneous pattern of pollution characteristics. Prior to implementing the cluster analysis technique, it is important to evaluate and transform the raw oily waste data using well-defined criteria. An advanced machine learning technique, fuzzy C-means clustering algorithm, is employed to classify the oily wastes. The Kolmogorov–Smirnov tests are employed to examine the statistical significance of clustered data. Results show a heterogeneous diversity in seven identified clusters in relation to different types of oily wastes. The cluster-based analysis method presented in this article is an integral part of an integrated optimization-based model which will provide valuable inputs for adjustment of the existing management practices, enhancement of short-term pollution control strategies, and development of long-term oily waste management policies. The output of this study would provide a better tool to waste characterization and sorting steps that are required to immediately separate recovered waste to support downstream response efforts. This result of this study also supports the overall goal of minimizing impact on the environment by ensuring the maximum amount of recovered waste can be recycled or disposed in an environmentally friendly fashion. Moreover, properly classified, sorted, and labeled waste will greatly help with downstream steps of packaging, transportation, and tracking of waste, and as a result, it will minimize total waste management time and costs, under the constraints involving waste storage and transport capacities, waste pre-treatment and treatment facility capacities, and environmental regulatory compliance, as well as other operational and logistic constraints.

Recent advances in chemical and biological degradation of spilled oil: A review of dispersants application in the marine environment

Growing concerns over the risk of accidental releases of oil into the marine environment have emphasized our need to improve both oil spill preparedness and response strategies. Among the available spill response options, dispersants offer the advantages of breaking oil slicks into small oil droplets and promoting their dilution, dissolution, and biodegradation within the water column. Thus dispersants can reduce the probability of oil slicks at sea from reaching coastal regions and reduce their direct impact on mammals, sea birds and shoreline ecosystems. To facilitate marine oil spill response operations, especially addressing spill incidents in remote/Arctic offshore regions, an in-depth understanding of the transportation, fate and effects of naturally/chemically dispersed oil is of great importance. This review provides a synthesis of recent research results studies related to the application of dispersants at the surface and in the deep sea, the fate and transportation of naturally and chemically dispersed oil, and dispersant application in the Arctic and ice-covered waters. Future perspectives have been provided to identify the research gaps and help industries and spill response organizations develop science-based guidelines and protocols for the application of dispersants application

Microplastic and oil pollution in oceans: Interactions and environmental impacts

Microplastics (MPs) have been found in oil-polluted oceans, but studies on MPs and oil were still focused on their respective transport, biodegradation, and bioaccumulation. The interactions between MPs and oil in the marine environment remain unknown. MPs would incorporate with oil to form MP-oil agglomerate (MOA), the behaviors of MOA were thus discussed in this study. It was found that the MOA formation resulted in the decreased oil dispersion efficacy and affect marine oil spill response operations. Moreover, oil biodegradation rate would be changed when oil existed as the form of MOA. The slow vertical transport of MOA might lead to wider ocean contamination. MOA would cause much worse impacts on phytoplankton, zooplankton, and high trophic species in the marine environment than MPs or oil individually. MOA assembling with phytoplankton in oceans may reduce carbon dioxide (CO2) transport to deep seas. Exploring the interactions between MPs and oil in the marine environment opened a door for understanding MPs and oil as co-contaminants.

Estimation of Aerosol Concentrations of Oil Dispersants COREXIT™ EC9527A and EC9500A during the Deepwater Horizon Oil Spill Response and Clean-up Operations.

The April 2010 Deepwater Horizon drilling unit explosion at the Macondo oil well resulted in the release of approximately 779 million l of oil into the Gulf of Mexico. As part of the response effort to break up oil slicks on the water's surface, 6.81 million l of chemical dispersants COREXIT™ EC9500A and COREXIT™ EC9527A were applied by plane or vessel or injected near the seabed. The GuLF Long-term Follow-up Study is investigating possible adverse health effects of workers involved in the oil spill response and clean-up (OSRC). In this paper, we describe potential dispersant-related air concentrations generated from aerial spraying of dispersants to provide insight as to what concentrations OSRC workers may have been exposed under worst-case conditions. Personal exposure measurement data were not collected. Modeling, therefore, was conducted to estimate airborne concentrations of total aerosol to COREXIT™ EC9527A and EC9500A. Using the AgDISP model, we estimated air concentrations to dispersant total aerosols, defined as all components of the dispersant including active ingredients, surfactants, and water, resulting from aerial and vessel applications, as average 1-h and 2-min concentrations. For comparison, 1-h air concentrations associated with aerial spraying were estimated using another model, AERMOD. At 152 m horizontal to the flight path, average 1-h total aerosol concentrations associated with aerial applications were estimated to be as high as 49.3 µg m-3 (9527A) and 45.4 µg m-3 (9500A), and both decreased with increased distance from the flight line. The estimates for spraying 9500A from vessels indicated that total aerosol concentrations were potentially as high as 0.33 µg m-3 at 10 m from the nozzles. These results suggest that personal exposures to dispersant aerosols were negligible.

Development of sludge-based activated char sorbent with enhanced hydrophobicity for oil spill cleanup

ABSTRACT Recovery of oil spilled on surface waters by the use of sorbents remains one of the primary oil spill response options available. To improve on this response measure, we have successfully fabricated an activated char (AC) sorbent material by pyrolysis of sewage sludge (SS), a readily available waste product generated across the world from wastewater treatment plants. The inherent Fe-minerals in SS texture were converted to magnetic Fe3O4 particles during the pyrolysis reaction. The AC provided a unique means to recover the sorbent after the oil sorption process with a magnetic field. Meanwhile, a superhydrophobic sorbent material with a water contact angle of 152.2° was created by the treatment of AC with myristic acid which could float on the water surface. Feasibility studies at the laboratory-scale were conducted with motor oil and light crude oil to evaluate its potential use in spill response operations. Results showed a sorption capacity of about 8.5 and 10.7 g/g for motor oil and light crude oil, respectively. Following the recovery of the test oils by ethanol stripping, the material could be recycled up to 5 times with trivial loss in sorption capacity. This research proposes a framework for the development of a highly efficient sorbent material for oil spill response operations from SS waste.

Estimation of Airborne Vapor Concentrations of Oil Dispersants COREXIT™ EC9527A and EC9500A, Volatile Components Associated with the Deepwater Horizon Oil Spill Response and Clean-up Operations.

The Deepwater Horizon (DWH) drilling unit explosion above the Macondo oil well on 20 April 2010 caused the release of approximately 4.9 million barrels (779 million L) of oil into the Gulf of Mexico. As part of a larger spill response and clean-up effort, approximately 1.84 million gallons (6.81 million L) of chemical dispersants COREXIT™ EC9500A and COREXIT™ EC9527A were applied to the resultant oil slicks through spraying on the water surface by plane and by vessel and through injection at the release source near the seabed. The GuLF STUDY is investigating the health effects of workers involved in the oil spill response and clean-up after the DWH explosion, and estimates of possible exposure to chemical dispersants were needed. Exposures were estimated to the volatile components of COREXIT™ EC9500A [petroleum distillates, hydrotreated light, and propylene glycol (PG)] and of COREXIT™ EC9527A [2-butoxyethanol (2-BE) and PG] using two of AIHA IHMOD2.0© mathematical modeling tools along with the dispersants' chemical and physical properties. Monte Carlo simulations were used to reflect uncertainty in input parameters with both the two-box, constant emission model and the near and mid field plume model for indoor and outdoor activities, respectively. Possible exposure scenarios considered various evaporation rates, sizes of the dispersant pool, wind speeds, and ventilation rates. For the two-box model, mean near field exposure estimates to 2-BE ranged from 0.9 to 5.7 ppm, while mean far field estimated exposures ranged from 0.3 to 3.5 ppm. Estimates of mean near field plume model exposures ranged from 0.01 to 3.7 ppm at 2.5 ft from the source, and <0.01 to 0.3 ppm at 10 ft from the source. Estimated exposures to PG were approximately 10% of the calculated 2-BE exposures and exposures to petroleum distillates about 40% higher than the 2-BE estimates. Results indicate that compared with current occupational exposure guidelines, overexposure to petroleum distillates and PG probably did not occur in our study, but under some conditions, for short periods, exposure to 2-BE may have exceeded the limits for peak exposures. These estimates were developed for use in job-exposure matrices to estimate exposures of workers having contact with dispersant vapors for the GuLF STUDY.

The Role of Human Factors in Maritime Environmental Risk Assessment: A Case Study of Oil Spill Response

Human error is one of the significant factors attributed to marine accidents. This paper aims to assess the potential contribution of human errors in improving maritime environmental risk management. Success Likelihood Index Method (SLIM), has been adopted to systematically estimate human error potentials for designated tasks in pollution prevention, along with fuzzy sets to deal with subjectivity in the process of using experts’ judgments. An oil spill response operation was investigated due to its considerable risks for the marine environment. Environmental factors, familiarity, and fatigue were observed as having a high impact on human performance. Besides its theoretical insight, the paper provides practical insights into the prevention of marine pollution. This study is presented as a reference providing a contribution to estimating the impact of human errors on maritime accidents. The paper is also intended to contribute to other risky industries where human errors can lead to fatal consequences.

A data-driven binary-classification framework for oil fingerprinting analysis

A marine oil spill is one of the most challenging environmental issues, resulting in severe long-term impacts on ecosystems and human society. Oil dispersants are widely applied as a treating agent in oil spill response operations. The usage of dispersants significantly changes the behaviors of dispersed oil and consequently challenges the oil fingerprinting analysis. In this study, machine learning was first introduced to analyze oil fingerprinting by developing a data-driven binary classification framework. The modeling integrated dimensionality reduction algorithms (e.g., principal component analysis, PCA) to distinguish. Five groups of biomarkers, including terpanes, steranes, triaromatic steranes (TA-steranes), monoaromatic steranes (MA-steranes), and diamantanes, were selected. Different feature spaces were created from the diagnostic index of biomarkers, and six ML algorithms were applied for comparative analysis and optimizing the modeling process, including k-nearest neighbor (KNN), support vector classifier (SVC), random forest classifier (RFC), decision tree classifier (DTC), logistic regression classifier (LRC), and ensemble vote classifier (EVC). Hyperparameter optimization and cross-validation through GridSearchCV were applied to prevent overfitting and increase the model accuracy. Model performance was evaluated by model score and F-score through confusion matrices. The results indicated that the RFC algorithm from the diamantanes dataset performed the best. It delivered the highest F-score (0.871) versus the lowest F-score (0.792) from the EVC algorithm from the TA-steranes dataset by PCA with a variance of 95%. Therefore, diamantanes were recommended as the most suitable biomarker for distinguishing WCO and CDO to aid oil fingerprinting under the conditions in this study. The results proved the proposed method as a potential analysis tool for oil spill source identification through ML-aided oil fingerprinting. The study also showed the value of ML methods in oil spill response research and practice.

Oil Spill Combat Strategy &amp; Lesson Learnt of Balikpapan Spill

Among many discussions on effective response strategies during oil spill response operations at sea, this paper elaborates comprehensive information on oil spill combat strategy and lesson learnt from Balikpapan Spill incident. The author tries to shown the effectiveness of assessment and surveillance prior to oil spill response operation, oil spill response strategies and monitoring after oil spill response operation. The paper point out strategies used by OSCT Indonesia as National Oil Spill Response Organization on responding the oil spill incident. Focusing on taking tactical response according to experience gained from previous oil spill incident, the paper also mentions the importance of unified command between local authorities and company for easier coordination. Other than strategies and effective response, wildlife response become one of the difficulties faced onsite the field due to diverse wildlife and lack of wildlife response knowledge and trained experts. Learn from this recent oil spill experience, may enrich the knowledge on responding to such oil spill incident at similar condition and area.

Step by Step to Implement SCAT during an oil spill response operation in Southeast Brazil

ABSTRACT Despite the best efforts of an on-water response to a large oil spill at sea, the likelihood is that at least some of the spilled oil will eventually reach the shoreline. When shoreline impact occurs, or is likely to occur, shoreline assessment is a critical component of the response and provides essential information for setting objectives, priorities, constraints and endpoints for an effective shoreline response.

Synthesis of photochemical transformations of oil in the sea

Abstract: In this presentation and article, we synthesize findings from a workshop about our understanding of the interplay between crude oil photochemical oxidation and oil spill response, emphasizing how this understanding has evolved since the 2010 DWH spill. Our discussion is guided by one overarching questions: what role does photochemical oxidation play towards informing effective oil spill response operations? We show that prior to the DWH spill, our understanding of the relative importance of oil weathering processes, specifically photochemical weathering, was incomplete. We further explore how accounting for photochemical changes to oil's properties (physical and chemical) could improve the effectiveness of oil spill response operations, specifically chemical dispersant applications. Lastly, we identify priority knowledge gaps related to this guiding research question.

Volunteers as an Integrated Part of the Oil Spill Response Capacity in Finland

ABSTRACT: Responding to a major oil spill is a labour intensive operation and involves several governmental and regional authorities, agencies and voluntary organisations. In Finland, The Finnish Border Guard is the competent pollution response authority that conducts the response measures in the event of an oil spill on the open sea. The RFRSs are in charge of oil spill response operations both in coastal and inland waters. The environmental agencies assist the RFRSs in executing the response operation e.g. by providing expertise in nature protection prioritisation. Along with the authorities, several non-governmental institutions as well as voluntary organisations are involved. Especially the Voluntary Oil Spill Response Troops of the World Wide Fund for Nature (WWF) Finland are prepared to assist in responding to an oil spill contaminating shorelines. The response capability of the WWF voluntary troops is based on long-term training and pre-education. Today, the troops consist of over 9000 volunteers, 3000 of which have completed response training and can easily be integrated into an authority driven operation. The collaboration between authorities and volunteers is regularly tested by means of co-operation exercises and real spill response cases. This paper studies the collaboration framework of the voluntary troops and the RFRSs and the benefits of the pre-established system.

Interactions between microplastics and oil dispersion in the marine environment

Microplastics (MPs) and spilled oil are both major concerns in the marine environment. In this study, we investigated if and how MPs would interact with crude oil and potentially reduce the effectiveness of oil dispersants applied during oil spill response operations. With the addition of dispersant, MPs and oil (covered by dispersants through their hydrophobic tails) formed MPs-oil-dispersant agglomerates that were found to exist from the surface layer to the bottom of the seawater column. Their resurfacing and sinking led to a decrease in oil dispersion effectiveness. Effects of MP concentration, MP aging, and dispersant-to-oil volumetric ratios (DORs) on oil dispersion were examined. We found that the dispersion effectiveness of light oil and heavy oil decreased 38.26 % and 38.25 %, respectively, with an increased MP concentration. The dispersion effectiveness of light oil and heavy oil was 82.86 ± 10.87 % and 40.39 ± 4.96 % with pristine MPs and increased up to 109.75 ± 0.71 % and 58.30 ± 0.00 % when using MPs aged for 56 days. MPs reduced oil dispersion effectiveness under different DORs. The findings of this first report to understand the interactions among MPs, oil and dispersants have provided fundamental insights that may influence future decision making on the selection and use of oil spill response strategies.

An integrated offshore oil spill response decision making approach by human factor analysis and fuzzy preference evaluation

Human factors/errors (such as inappropriate actions by operators and unsafe supervision by organizations) are a primary cause of oil spill incidents. To investigate the influences of active operational failures and unsafe latent factors in offshore oil spill accidents, an integrated human factor analysis and decision support process has been developed. The system is comprised of a Human Factors Analysis and Classification System (HFACS) framework to qualitatively evaluate the influence of various factors and errors associated with the multiple operational stages considered for oil spill preparedness and response (e.g., oil spill occurrence, spill monitoring, decision making/contingency planning, and spill response); coupled with quantitative data analysis by Fuzzy Set Theory and the Technique for Order Preference by Similarity to Ideal Solution (Fuzzy-TOPSIS) to enhance decision making during response operations. The efficiency of the integrated human factor analysis and decision support system is tested with data from a case study to generate a comprehensive priority rank, a robust sensitivity analysis, and other theoretical/practical insights. The proposed approach improves our knowledge on the significance of human factors/errors on oil spill accidents and response operations; and provides an improved support tool for decision making.