BUILDING INTEGRATED ASSESSMENT TOOL FOR DAMAGE CAUSED BY OIL SPILL ON VIETNAM'S COAST Hoa Nguyen Thi Thaia and Long Bui Tab a
Graduate student, Institute of Environment and Resources, Vietnam national university Hochiminh city,
142 To Hien Thanh str., Dist. 10, Hochiminh city, Vietnam, Tel. 884 – 8 – 38651132#31, E-mail:
[email protected] b Assoc. Prof. Dr.S., Institute of Environment and Resources, Vietnam national university Hochiminh city, 142 To Hien Thanh str., Dist. 10, Hochiminh city, Vietnam, Tel. 884 – 8 – 38651132#31, E-mail:
[email protected]
KEYWORDS: Oil spill, Modeling, GIS, Environment Information System, Mike ABSTRACT. Vietnam's seas are focused of oil and gas fields currently operating with high intensity. Exploration and exploitation take place on many seas of the country, so risk of oil spills is highly. In fact, from 1997, Vietnam has more than 50 oil spill accidents; on average each year more than three accidents and the majority of accidents are not compensated. It shows the necessary to have a reliable simulation tools for supporting the rescue and can quickly assess the damage, provided the basis for damage caused by incidents. Outstanding results of this paper is built the tools SOSPCET (Simplified Oil Spill Prediction and Cost Estimation Tool), combined model Mike 21/3 SA with damage assessment model to support the managers quickly identify the contaminated areas to take right decisions when problems occur and estimate the damage caused by the incident. This is the basis for the decision to impose sanctions and compensation. 1
INTRODUCTION
The economic and social development in all countries around the world depends heavily on petroleum materials. Therefore, exploitation and transportation of crude oil and petroleum products is increasingly, and from which the risk of oil spill is increasing too. According to statistics from NOAA - National Oceanic and Atmospheric Administration, these agency responses to 150 oil spill accident annually, this is a huge amount. The loss of socioeconomic and environmental due to oil spill accidents is very high, so there are many studies about forecasting methods for tracing the movement of oil after the accident and environmental damage assessment methods. The results predict the movements of oil spill are used as the basis for the rapid deployment rescue, it is effective and less costly. The results of the environmental damage assessment help the agency for determining the exact areas affected and the appropriate recovery method, there is also the basis for competent authorities to force the ones who make the accident happening compensate for the losses they caused. In this area, which include oil spill simulation module Mike21/3 PA/SA in Mike from the Danish Hydraulic Institute building (DHI, 2007a, 2007b). Damage assessment method caused by oil spills and damage assessment process were developed by NOAA and were apllied by many countries around the world. This process includes three steps: First step, pre-assessment, this stage given the information necessary to 1
decide whether it is necessary to assess damage and plan recovery or not. This step also makes the initial assessment, data collection and analysis and development plan preliminary damage assessment. The second step - recovery plan be carried out to assess the damage or loss, the recovery method. The third step is deploying the recovery operation. This step is implementing activities according to plan and carry out the compensation demanded by accident. This process is carried out by many experts in many different areas, with long and large amount of information data, the accuracy of the method is very high. That is why the process is more applicable over the world. However, the application process for Vietnam is facing many difficulties due to lack of data as well as the lack of specialists. Environmental Protection Agency built a rapid assessment of economic losses and social environment from oil spill accidents called BOSCEM (Basic Oil Spill Cost Estimation Model). BOSCEM based on analysis synthesis of oil spill accidents that happened in history on the side: the rescue, economic and social damage to environmental resources. In addition, BOSCEM also incorporates the elements and methods of evaluation of environmental losses, such as compensation costs of Washington (Geselbracht and Logan, 1993) and compensation fees of natural resources from sources in Florida (Plante, et all., 1993). The methods, standards and cost coefficient to assess the social and economic damage, including the impact on the tourism sector in particular and the region as a whole, the loss of use value of parks, recreational areas, conservation areas ... are taken from previous studies as well as the methods used in other studies (Pulsipher, et al., 1998; U.S. Army Corps of Engineers, 2000a, 2000b). 2 2.1
METHODOLOGY Oil spill analysis module Mike 21 and Mike 21/3 PA/SA
Figure 1. Solving oil spill problem based on module Mike 21 and module Mike 21/3 PA/SA.
Currently there are many oil spill analysis model used all over the world. Model selecting is very important in the calculation process, this work is based on the researched goal and databases collected. In this study, MIKE software has been selected, using module Mike 21 Mike 21/3 PA/SA is shown in Figure 1. 2.2
Topographical and boundary data •
Preparing the topographical data for Mike21 2
Currently the data used to calculations is posted on the Internet, so users could exploit this data source. Subjects examined in this study are the coastal province of Ba Ria - Vung Tau. Terrain data base is taken from google earth.Water level data are taken from http://www.waterforecast.com/globaltide/. For solving oil spill problem, the authors selected data from offshore. With such data, the calculation will be larger and makes the computing time increases. This will be processed in two steps. Firstly, build the terrain for large areas with large grid steps, then build the terrain for smaller areas with smaller grid step. This way will solve the accuracy of the data. Data are taken from Google Earth will be processed in Surfer and MapInfo software to obtain terrain data file as required by the Bathymetry Editor of Mike. Data after preprocessing is included in the Bathymetry Editor of Mike21 to create terrain. The topography of large areas - to get the water level - and small areas - to calculate a more accurate spreading. •
Prepairing boundary data
On the bottom boundary and right boundary of the area, some points are determined along the boundary, then take the coordinates of points into http://www.waterforecast.com/globaltide/ page to retrieve the parameters amplitude and phase of waves M2, S2, K1, O1, N2, P1, K2, Q1; using these parameters to interpolating the water level data. Based on water at a point on the boundary, taking the average value of these points to get water level data on that boundary. 2.3
Hydraulic model Mike 21 HD
This is the core modul and most important of Mike21. The parameters chosen for the hydraulic calculations are given in Table 1. Table 1. The parameters are chosen to run Mike 21 HD
No. 1 2 3 4 5
Parameter name Value Bathymetry is prepared above Boundary conditions is prepared above Simulated time 1:00:00 – 19:00:00 01/03/2011. Rough 32 Other defaul parameters The results from the hydraulic model Mike 21 HD is shown in Figure 2 - Figure 3
Figure 2. The hydraulic results on the large area
2.4
Figure 3. The hydraulic results on the small area
Module Mike 21/3 PA/SA
Module Mike 21/3 PA/SA based on Lagrange approach, the movement of all molecules of pollution was calculated at the same time rather than the transmission - diffusion in Eulerian 3
approach. The molecules of oil pollution under the impact of diffuse flow and movement disorders. The diffusion of the flow is taken from the results of hydraulic model - Mike 21 HD assuming motion puppet controlled by the coefficient of dispersion. The molecules of oil pollution is characterized by the physical quantity such as density, evaporation, melting point, ... the Mike 21/3 PA/SA has noted the change of volume of oil spill by weathering processes such as emulsification, evaporation, precipitation and dissolution. Module Mike 21/3 PA/SA solving diffuse transmission through Langrange method and solve the weathering processes through the equations of spreading, evaporation, vertical dispersion, dissolution, emulsion, heat exchanger, the influence of physical characteristics and chemistry of the oil. 2.5 Damage assessment model
Figure 4. Model oil spill damage assessment (Source: EPA)
Effection of factors such as amount of oil spilled, oil properties, socioeconomic and cultural value and sensibility of affected area … etc to some kinds of response cost is presented in Figure 4. Total damage caused by oil spill accident is estimated by spill response cost, socioeconomic and environmental damage and these kinds of cost are represented in following formula: Total damage = total response cost + total socioeconomic damage cost + total environmental damage cost. Each operand is determined as follow: Total response cost = pergallon response cost x medium modifier Í effective response modifer Í spill amount; Total socioeconomic damage cost = per-gallon socioeconomic cost Í socioeconomic cost modifier x spill amount; Total environmental damage cost = per-gallon environmental cost Í 0.5 (freshwater modifier + wildlife modifier) Í spill amount. 3
RESULTS AND DISCUSSION
From the methodology described above, the author made a specific oil spill scenario. Oil spill simulation results from Mike 3 PA/SA was associated with damage assessment model (Fig. 4) and given the amount of damage to the incident to illustrate the simulation and rapid damage assessment of pollution.
4
The scenario chosen is described as follows: the oil spill is Buoy 0 in Ganh Rai bay, Ba Ria-Vung Tau. This is where passing ships customs procedures so the risk of oil spill occurring at this location is very high. Type of oil was diesel oil (oil used in transportation waterway), the simulation parameters are given in Table 2. Table 2. The parameters to run Mike 3 PA/SA
No 1 2 3 4 5 6 7 8 9
Parameter name Spilled source: Drift signal 0 Oil spill volume Sea temperature Salinity Air temperature Wind speed at 10m above mean sea level Horizontal diffusion coefficient Vertical diffusion coefficient Other default model parameters
Value
Dimension
800 25 33 28 4–6 4 4
m3/ngày o C o /oo o C m/s m2/s m2/s
Result from Mike 3 PA/SA is shown on Figure 5 - Figure 6.
Figure 5. Simulation results fifteen hours after the incident – oil streaks spreading along the coastal.
Figure 6. Simulation results sixteen hours and thirty minutes after the incident – affected area expanding.
Calculation results show the range affected by the oil spill in the area of Front Beach, Vung Tau city. This area focuses restaurants and luxury hotels, parks and an attractive place for tourists. Here are the sensitive areas, high value economically as well as meet the needs of entertainment and relaxation of people. From the nature of the affected areas and the oil spill is assumed above; the authors propose the parameters of the damage to affected areas in Table 3. Table 3. The parameters of the damage and losses estimated for incident
Parameters
Selected value 154 $ 1 1 220 $ 1.7 40 $ 1 1.5
Per-gallon response cost Medium modifier Effective response modifer Per-gallon socioeconomic cost Socioeconomic cost modifier Per-gallon environmental cost Freshwater modifier Wildlife modifier 5
From the parameters chosen in Table 3, combined with a rapid assessment of damage has been discussed in the section 2, the cost of rescue, socioeconomic costs, environmental costs and losses due to incidents are showed in Table 4. Table 4. The costs and total damage estimates for incidents
Cost types Total spill response cost Total socioeconomic cost Total environmental cost Total damage
Value ($) 32546 79040 10567 122153
Thus, with the damage parameters are chosen, along with the damage model was quickly determined the damaged by oil spills. These results allow us to determine the damage quickly and conveniently. 4
CONCLUSION
The results of this work showed the feasibility and effectiveness of combining software Mike and economic model of environmental damage assessment of oil spill on the coast of Vietnam, to support the rescue and determine of damage as the basis for the compensation. For the results more reliability and legality, need of data on topography, meteorological .. are measured and explored, as there should be additional research on the effects of oil spill to socioeconomic and environment to build the data fit the actual conditions in Vietnam. This is what the authors wish to develop in the future. Through this paper, the authors hope to get many discuss and can be applied to the problem of oil spill on concerned countries 5
REFERENCES [1]. DHI, 2007a. Mike21 flow model FM. Hydrodynamic model. User Guide. 74 pp. [2]. DHI, 2007b. Particle Analysis and Oil Spill Analysis Module. User Guide. 108 pp. [3]. Geselbracht, L., and Logan, R., 1993. Washington’s marine oil spill damage compensation schedule – Simplified resource damage assessment. Proceedings of the 1993 International Oil Spill Conference: pp. 705 – 709. [4]. Plante, K.J., Barnett, E.L., Preble, D.J., and Price, L.M., 1993. Florida’s Pollutant Discharge Natural Resource Damage Assessment Compensation Schedule – A rational approach to the recovery of natural resource damages. Proceedings of the 1993 International Oil Spill Conference: pp. 717 – 720. [5]. Pulsipher, A., Tootle, D., and Pincomb, R., 1998. Economic and Social Consequences of the Oil Spill in Lake Barre, Louisiana. Louisiana State University Center for Energy Studies/Louisiana Applied and Educational Oil Spill Research and Development Program/Minerals Management Service. Technical Report Series 98-009. 27 pp. [6].
US Army Corps of Engineers. 2000. Civil Works Construction Cost Index System. EM 1110-2-1304. US Army Corps of Engineers, Washington, DC.
[7]. US Army Corps of Engineers. 2000. Economic Guidance Memorandum 01-01: Unit Day Values for REC., Fiscal Year 2001. US Army Corps of Engineers, Washington, DC. November 2001. 10 pp. 6
