GIS-Based Emergency Management Scenario for Urban Petroleum Storage Tanks Muhammad Anjum, Marriyam Rana and Jelena Ivanova Disaster and Emergency Management Graduate Program, York University, 4700 Keele Street, Toronto, Ontario, Canada, M3J 1P3 Abstract— Petroleum storage facilities in the middle of a city, neighboring residential and educational community are a serious risk. This paper presents GIS-based scenario for petroleum storage tank explosion, in a mid of a large city. The scenario investigates data requirements, modeling approach and highlights a wide range of emergency management issues. The paper stresses on the limitations that emergency managers may face using GIS for similar scenarios. It was concluded that as a result of cost/benefit analysis it might not be feasible moving large petroleum storage facilities to the outskirts of cities, given the factor of rapid urbanization. However, emergency managers must realize that mitigation policies for a potential disaster triggered by an oil terminal explosion need to focus on better safety standards and constant training of staff to ensure the quality of terminal operations. Keywords: GIS, Disaster, Emergency, Oil Tanks
I.
INTRODUCTION
Petroleum is a commodity that is scarce and invaluable in this age. While it offers great conveniences and is vast in its scope, from running our vehicles to being used to create plastics, fertilizer, wax and other products; yet, it does not come without a cost. It can also be one of the causal factors of several ecological, environmental, industrial, infrastructural fatal disasters [1]. Since this substance can cause contamination and explosion if not stored and transported safely, it is of utmost importance that we take special care and have emergency measures in place in case something does go wrong; which may result in an upgrading potential hazard to become a full blown disaster. Historically, the chances of successful fire control and extinguishment have been low, especially for larger oil tanks [2]. This makes it even more crucial for Emergency Managers to constantly research ways of mitigation, preparedness, response and recovery in this context. Since petroleum terminals are usually privately owned, there is a limited role in mitigation that municipal emergency managers can perform at the site itself. However, it becomes policy issue in terms of creating a solid and enforceable response plan, which represents a type of mitigation measures that would help prevent a small disaster from becoming one that is potentially catastrophic in nature. It is important to mention that this scenario provides high resolution highly dense urban environment. This magnifies the challenge of emergency management decision makers and enforces the need for coordination with utilities internal
Rifaat Abdalla Defence Research and Development Canada – Toronto, 1133 Sheppard Avenue West, Toronto, Ontario, Canada, M3M 3B9, e-mail:
[email protected]. authorities dealing with safety and emergency management policies and regulations, as well as business continuity professionals in the field. II.
SCENARIO & SUTDY AREA
Our objectives are to use GIS to identify the closest emergency response facilities surrounding the Keele terminal, and this includes police, fires, and EMS. We wanted to calculate routes for the distance and time it would take for these response teams to arrive at the incident site. The scenario was mocked as following: On October 4th at around 5PM the explosion of the oil terminal shook the area around Keele and Finch, across from York University, 4700 Keele Street, Toronto, Ontario, Canada. The reasons for the explosion are still unknown but preliminary statements link it to technical failure in the tank safety system. The most crucial factors that impact such event are aggravating conditions, such as the time of the event, which may impact public transportation and traffic. Both Keele and Finch (the nearby intersection as shown in Figure 1.) have one of the heaviest traffic with the 56-80 seconds delay per vehicle [3]. Therefore number of people that were in the area surrounding the explosion would be much higher than it would have been in other time of the day, the month is also important, whether if schools nearby are populated or not. Another important impact factor is the surrounding infrastructure.
Figure 1. High resolution imagery showing the studay area
III.
DATA
Based on the objectives and the scenario of this study, we have defined three major layers of interest that are essential to the achievement of this research objectives i.e. to assess
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the damage due to oil terminal explosion, identify the location of response units (Fire, Police and Emergency Medical Services “EMS”) and plot the most efficient routs for the response units. DMTI data licensed to York University was used along with layers from the Geography Network and GeoGratis. Data from Toronto Emergency Services (TES) which included fire departments, emergency medical services (EMS) was manipulated based on textual information in TES website, due to issues related to access right of the data. We obtained vector layers for Toronto municipal boundaries, major roads, streets, major highways, educational points, healthcare points, public transport points, utility lines, police, firefighters’ stations and Emergency Medical Services (EMS). IV.
three clips, and “union” tool was used to get the EOC; map the ‘clip ‘function was then used to highlight the risk map from the target map. The ‘clip’ function was also used to show the blocked roads in the risk area to divert the public traffic and to keep the roads free for the emergency vehicles. The cartographic model was run successfully [5]. In creating the cartographic model, it was possible to focus the scope of the research and GIS by creating a 1 km buffer that was divided into red, orange and green. Through this model, It was possible to identify most vulnerable populations and estimate spatial losses and levels of risk in order to respond appropriately. By adding demographic, utility, infrastructural data we were able to satisfy all the earlier stated requirements.
METHODS
A. Creation of Spatial data/ shape files In order to identify any point on the map it is essential to know its precise location, if address is not available, the use of geographic coordinate system (latitude and longitude) is the option in this case. First we obtained the oil terminal address from the internet and identified its latitude and longitude (x, y coordinates) using Google Earth. We did the same for other data which was manipulated from textual information. Then, hospitals, police and fire stations were mapped using the same method, based on MS Excel spreadsheet using the x, y locations data for each emergency service separately and added them to the GIS map attaching relevant symbol. The following step involved converting the Excel data file to a shape file to show the location points on the map. In order to accomplish this, Geographic Coordinate System (GCS_North_American_1983) needed to be linked with the file. Using the same process we created the oil terminal layer and the Emergency Operation Center (EOC). The location of the EOC (a place where coordination of emergency response is managed) has been chosen so that it would be close to the incident but far enough to ensure the safety of the centre as well as close to the major road to be easily accessible. B. Cartographic Model A cartographic model was developed to list the logical sequence of the project. First, we targeted an overall map (target map) of potential explosion site, based on the scenario and the locations of emergency services. Second, we highlighted the risk area (risk map) and identified its parameters and what falls within it. Based on our literature review, we created three zones; a high risk (red) zone of 300 meter radius, a medium risk (orange) zone of 600 meter radius, and a cold (green) zone of one kilometer radius. There is no precedent of damage beyond one kilometer except the smoke that can cover a larger area depending on the winds direction and other environmental factors [4]. Model builder module of ArcGIS 9 was used in addition to ‘spatial join’ function tool eleven times to get all the necessary layers and points on the target map, three buffers,
Figure 2. Impact zones, based on the developed scenario
C. Attribute data processing The following step was to acquire census data to determine the number of people, their demographic details, structural information of the buildings, their usage (“land use classes” whether commercial or residential) and their dollar value. The census data obtained from York map library was coded and it was difficult to understand what data actually related to our target areas. With the help of a dictionary provided by Statistics Canada, we were able to find the codes and chose the two files that were directly related to our required data. These two track files were then added to the base map. V.
RESULTS AND DISCUSSION
Upon completion of all the stages of mapping and information gathering, the analysis of damage was complete. Because the proximity is close to York University, it was possible to visually validate the model whether residential and business buildings are at risk due to their proximity to the simulation scenario. A. Population Based on the information obtained from the census data, it was possible to assess population concentration polygons. One of the polygons had 15% of the area within the buffer zone; polygon two had 20% and 60% of the area of the third polygon. Based on this data we were able to identify 56 individuals i.e. one percent of the total population that falls
within the buffer zone is at high risk, taking into account human ability to move away from the danger i.e., self evacuate. Three educational institutions including, York University with approximately 50,000 students currently enrolled fall within one kilometer of our study area. In addition, there are some businesses, a GO bus terminal (as per data set provided), approximately 5649 individuals, and 2282 building units that are valued at over one thousand million dollars. Out of the above mentioned individuals, we gauged that 56 (1%) can potentially be critically injured and 228 building units (10%) at risk which are worth of more than a hundred million dollars as the direct damage (Appendices C and E). Environmental damage needs another assessment which is beyond our project scope. Mapping the emergency services routes and timing allowed for identifying three stations for emergency services located in the neighboring vicinity. This is in addition to three fire stations, two hospitals, and two police divisions which are located less than 3 km from EOC. (i.e., about 4 minutes with the average speed of 70km/h), whereas one of the fire department falls in the red zone and the other one is less than 8 km and access time to incident site by a private passenger vehicle is 11 minutes as per Google Maps. The utility lines i.e. electricity, natural gas, and water fall under the “high risk zone” 136 meters from the incident with only 27 meters in between the lines. In case of an explosion or fire, these services are at great risk. Service interruption would occur far beyond the area as utility lines are in a network that spread across the area. As a result, there is a risk of deprivation of these utilities for long hours; if fire reaches the gas and electricity pipelines, the damage could go far beyond the 1 km radius around the petroleum tanks. This is causing a ripple effect that could incur a greater loss and would be even more challenging to control and recover from [6]. An additional point of concern is that there are multiple tank farms in the proximity. These other oil storages fall under the orange zone. The utility pipelines in addition with a strong wind can trigger a cascading effect; which could be an uncontrollable disaster. The Hydro Corridor will be affected, specifically, the Richview-Cherrywood line, which has 230kV tower lines which have provision for up to 8 circuits. Apart from the Hydro line, Sarnia Product and Trans-Northern Pipelines run in this Hydro corridor. The short distance between the pipes poses a serious risk to a much larger area than the buffer zone and devastating effects of the fire/explosion in the terminal. Not only is electricity supply to the area in potential danger but also the fact that the pipeline that runs right under Finch Street can be affected leading to a restriction in access to the incident. In addition, 228 building units, i.e. ten percent of the total buildings that are at risk and their respective dollar value 90 million dollars property could be destroyed or damaged other than the oil facility itself.
Figure 3. Damage assessment to utility lines, transportation and displace population in each risk zone.
One of the objectives of this project was to map and analyze the response time and distance for Emergency Medical Services (EMS), Fire and Police. In order to identify the number of Police and Fire units that would be involved at the initial stage of response to the incident it was crucial to get the information on number of fire trucks per division, capacity and staff members. 1) Fire Department: The study area is attached to the following four fire stations: 141, 142, 143 and 146. Proximity is a key identifying factor and according to one of the internal sources, five minutes is the standard time of response, therefore if the building is located more than four minutes away it is usually reattached to a closer Fire station. With regards to the response itself as well as staffing of fire hauls in the GTA, a Fire Fighter has provided the following information: a) Generally, every truck in the GTA has 5 personnel on it, but due to absence (sick, vacation etc) it averages around 4 fire fighters b) the dispatch system: assigned trucks on first alarm c) high risk locations such as the tank farm on Keele street have pre-set response procedures d) in case of an explosion (lightening for example) at the tank farm, there are three potential response stages of response depending on need: First response: 2 pumper trucks, 1 Aerial, 1 rescue and the district fire chief. Second response: 2 additional trucks and support staff. Third response: Additional support as needed. e) There is no general number of trucks per fire haul. Each haul has a different capacity. For example, a haul in a residential area may only house one fire truck (may vary between 1-5 trucks). In light of this information, it was decided to highlight two routes for each fire station identified (as it is not clear which particular station will be assigned by the dispatch system). We ended up with the two – main and alternate routes for each station. The assumption for the alternative route identification is based on the blockage of the two main intersections – Keele/Finch and Finch/Dufferin. Fire route 1 which accounts for the main road paths is 3.9km to the incident site which takes 5 minutes taken the average speed of 60KM/hour. The alternative route from the same fire station to the incident (using the side/inner roads) is 4.6km
which is 9 minutes of traveling time. We do realize that Fire trucks will be travelling with the speed higher than the average private passenger vehicle but we decided to take 60KM/hour which will account for the delay due to traffic [7, 8].
traffic heavy main lanes for the EMS, police and fire to get to the place of the incident. Cleary it was a complicating factor which had to be included in incident projection.
2) Police: Division 31, 32 and 33 will respond to the incident in the scenario. However, two of the divisions were located too far to be considered for the first response to the incident, and were kept in the map for possible back up to the responders but were not included in primary route identification.
AVERAGE DISTANCE (KM)
AVERAGE TIME (MINS.)
Fire Route Alternate Fire Route Police Route Alternate Police Route To NY General Hospital
3.9
5
4.6
9
3.2
5
4.7
8
4.2
7
Alternate to NY Hospital
7.6
Table 1. Estimated travel time for evacuation routes
1 2
NY refers to North York Hospital -Bronson site
Figure 4. Simulation of emergency response for police force
3) Traffic in the area: Detailed information on traffic around the area was obtained from Toronto Transit Corporation (TTC). However, one of the limitations was that it was descriptive data. Therefore, it was impossible processing textual data without ensuring that we incorporated this data in the GIS database.
This model would have benefited significantly if environmental parameters such as air quality and pressure were used. This could have allowed for modeling the wind speed and direction and would have helped identifying the area that would be at a higher risk of fire damage; as the wind would accelerate the spread of the fire towards a particular direction. When air is heated it expands, becoming dense and rises creating an area of low pressure at the surface. As the warm air rises it begins to cool, eventually causing it to sink back to the surface creating an area of high pressure. In general, air flows towards areas of low pressure and away from areas of high pressure [9]. This information would have been definitely valuable addition allowing more specific analysis of pollution and volatile organic compounds in the air, and would allow for smoke plume modeling. Construction data as well could have allowed for detailed risk assessment for the buildings around the oil storage, specifically, assessing the fire susceptibility. In addition, the damage and losses due to explosion could be assessed in greater details if information such as groundwater contamination and/or the network of oil supply from Keele facility could be incorporated the project database.
According to TTC Environmental Assessment report completed by TTC and the City of Toronto, Keele and Finch area is identified as heavy traffic flow area. According to the report Keele street traffic flow ranges from 500 vehicle/hour to the peaking 3000 at 6PM. These numbers are the total for both Southbound and Northbound. For the Finch Ave the trends are similar to Keele Street with minimum of about 600 vehicles per hour at 00 hours and peak of 3600 vehicles at 5:30PM. Clearly, the volume of the traffic especially in the period of 5-6 PM is heavy, therefore if the explosion is going to happen at that time the disruption of the traffic as well as the number of potential casualties may increase. One of the assumptions from the traffic flow that could be considered is that the land use classes in the area are dominated by commercial/business classes of buildings, as such the traffic peaks from 5-6PM, as a result of the end of business day for the majority of business in the city.
Petroleum storage facilities in the middle of a city neighboring residential and educational community are a serious risk. Utility lines passing underneath storage facility should be moved to a safer location. A safety wall around the facility is recommended to be built immediately. The simulated case shows that the emergency containment wall around the tanks were able to hold the fluid controlled in the aftermath of explosion.
One of the critical findings was that right in the perimeter (polygon) of our area of interest between Keele and Finch (where the terminal is located) TTC have identified the internal streets with heavy traffic flow. This fact had to be included into the report not as contributing factor to greater vulnerability for greater number of people, as well as the fact that internal streets would unlikely be used as alternative for
It has been realized that the proximity of petroleum storage facilities is a result of city expansion outwards due to rise in population. The cost/benefit calculation of moving the utility lines will become a factor that would make such project be unattainable. Therefore, emergency managers must realize that mitigation policies for a potential disaster triggered by oil terminal explosion need to focus on better
VI.
CONCLUSION & RECOMMENDATIONS
safety standards and constant training of the staff to ensure the quality of Terminal operation. In addition to that, it is crucial to organize evacuation procedures with the quarterly exercises that would involve staff of the facility as well as residents of the surrounding area. The starting point should be the information dissimilation of the risks and dangers that the oil terminal has and GIS project that we have accomplished can be a good visual aid to make the matter more clear for the stakeholders. From policy side, coordination between emergency management authorities
and local communities are crucial for successful response and future preparedness. This stresses on the importance of documenting lessons learned, specifically in modeling and simulation for future policy auditing.
VII. REFERENCES [1]
Figure 5. Simulation of simultaneous emergency response for emergency services.
Camps, R., Controlling the Danger Zone, in New Scientist. 1993. p. 16. [2] Mebaraki, A., Q.B. Nguyen, and F. Mercier, Structural Fragments and Explosions in Industrial Facilities: Part II - Projectile Trajectory and Probability of Impact. Journal of Loss Prevention in the Process Industries, 2009. 22(4): p. 417-425. [3] Toronto Transit Commision (TTC), Environmental Impact Assessment for the Extension of Spadina-York Subway Line. 2008: Toronto [4] ESRI, Environmental Research Inistitute. GIS for Emergency Management., in White Paper. 1999: Redland, CA. [5] Cova, T.J. and R.L. Church, Modelling Community Evacuation Vulnerability using GIS. I. J. Geographical Information Science, 1997. 11(8): p. 763-784. [6] Paik, J.K. CFD Simulations on Gas Explosion and Fire Actions,” Proceedings of MARSTRUCT 2009. in 2nd Int.Conf. on Marine Structures Analysis and Design of Marine Structures. 2009. [7] Kim, S. Route Planning: Scalable Heuristics. in Proceedings of the 15th International Symposium on Advances in Geographic Information Systems ACM GIS 2007. 2007. [8] Johnson, K. GIS Emergency Management for the University of Redlands. in ESRI International User Conference 2003. [9] Brabhaharan, P., G.K. Bharathy, and R. Lynch. Natural Hazards Risk Associated with Petroleum Storage. in Pacific Conference on Earthquake Engineering,. 2003. New Zealand. [10] Schneider, D., “Lightning sparks explosion; no one hurt ” Online Resource, Available http://www.unitliner.com/news.html. Published in 2007. Accessed Nov 15, 2010.
