Page 1 of 1 Towards Efficient Disaster Management in Oil Pipeline Corridors: Example from Nigeria Omonisini, E.O Institute of Ecology and Environmental Studies Obafemi Awolowo University, Ile-Ife, Nigeria esfunmi@yahoo.com Eludoyin, A.O Department of Geography Obafemi Awolowo University, Ile-Ife, Nigeria oaeludoyin@yahoo.com Salami, A.T Institute of Ecology and Environmental Studies Obafemi Awolowo University, Ile-Ife, Nigeria asalami@yahoo.com Introduction In 1956, Shell British Petroleum (now Royal Dutch Shell) discovered crude oil at Oloibiri, a village in the Niger Delta, Nigeria, and commercial production began in 1958. Today, there are about 606 oil fields in the Niger Delta, of which 360 are on-shore and 246 offshore (Nigeria Country Analysis Brief, 2005). These have been parcelled out to the oil multinationals for extraction (Egberongbe, 2006). Nigeria was one of the world's largest oil exporters; the country is now the largest oil producer in Africa and the sixth largest in the world, averaging 2.7 million barrels per day (bbl/d) in 2006. As a result of the numerous small fields, an extensive and well-developed pipeline network has been engineered to transport the crude. In general, Nigeria has a total network of about 5,001 kilometres of oil pipelines, consisting of 4,315 km of multi-product pipelines and 666 km of crude-oil pipelines (Brume, 2002). These pipelines criss-cross the country and inter-link the twenty two petroleum storage depots strategically dispersed across the country; including the refineries at Port Harcourt, Kaduna and Warri, the off-shore terminals at Escravos and Bonny, and the four jetties at Okrika, Atlas Cove, Warri and Calabar. For reasons of safety and security, these pipelines are buried about one metre beneath the surface along a 25-metre wide Right of Way (ROW), specifically acquired by Government for the purpose. This ROW is regularly cleared by the host community acting as contractors (Nigeria Country Analysis Brief, 2005). Pipelines and their associated facilities pose potential environmental pollution risk that could be of security concern for the vulnerable communities. Pipelines are required to meet all environmental pollution risk hazardous waste management standards. Hazardous wastes related to the transport process of oil and gas in pipelines is fully covered by environmental pollution risk regulations for the control of hazardous material. Today advances in information systems, satellites imaging systems and improved software technologies have led to opportunities for a new level of information products from remote sensed data. The integration of these new products into existing response systems can provide a wide range of analysis tools and information products that were not possible before. Using the higher resolution imagery and change detection analysis pipeline situational awareness and damage assessment can be conducted rapidly and accurately. Power utility infrastructure and system wide evaluations over a broad area could also be addressed using remote sensing data sources (Rustamov et al., 2006). In Nigeria, a combined team of PPMC, Community Leaders, Police and local security outfit provide surveillance to guard the pipelines. Regular aerial surveillance of critical sections of the pipelines is also carried out by PPMC/NNPC (Nigeria Country Analysis Brief, 2005). In spite of these security measures, statistics on oil pipeline vandalisation remain staggering. According to Nwalo et al., (2005) about 50 per cent of the cases of oil spillage are due to corrosion, 28 per cent to sabotage and 21 percent to oil production operations. Only 1 per cent of the cases have been adduced to problems associated with engineering drills, inability to effectively control oil wells, failure of machines, and inadequate care in loading and unloading oil vessels. In all the forms, it has been gathered that the significant number of cases of spillage (outside the current militia sabotage in the last one year in the Niger Delta area). By international standards, oil pipes ought to be replaced after 15 to 20 years, but most pipelines in use in Nigeria are about 20 and 25 years old, making them vulnerable to corrosion and leakage. In some cases, the pipes are laid above ground level without adequate surveillance, exposing them to wear and tear and other dangers (Oyem, 2001). Anderson (2005) also noted that most of the facilities were constructed between the 1960s and early 1980s to the then prevailing standards). The oil pipeline in the coast of Lagos that was buried upon lying is now exposed to the surface by the process of erosion (Fig. 1). Settlements as well as farming activities have encroached on the ROW. In most cases, information about these vulnerable settlements and land use is scarce and are rarely noticed until a number of victims perish after a disaster. The main objective of the present study is therefore to demonstrate the application of Remote Sensing and Geographical Information System in creating efficient scenario towards the management of oil spillage induced fire disaster in the study area. The study was with the view of introducing the policy makers to the potentials of the technologies of RS and GIS in providing a spatial decision support information/   Figs 1a and b: Photographs showing an exposed oil pipeline (a) and oil leakage from the pipeline in one of the communities (Ilado) in Amuwo-Odofin LGA, Lagos, Nigeria Study Area Amuwo-Idofin LGA is located along the Badagry Creek of Lagos in south-west Nigeria and lies between 6° 24'N3° 20'E and 6° 26' 00? N 3° 22' 30? E (Fig. 1). It experiences two rainy seasons, with peaks in April -July and October -November. There is a brief relatively dry spell in August and September and a longer dry season from December to March. Monthly rainfall between May and July averages over 300 mm, while in August and September it is down to 75 mm and in January as low as 35 mm. The main dry season is accompanied by Harmattan winds from the Sahara Desert, which between December and early February can be quite strong. The average temperature in January is 270° C and for July it is 25° C. On average the hottest month is March; with a mean temperature of 29° C; while July is the coolest month. The study area is in the neighborhood of oil pipeline and comprises of settlements such as Ilado-Odo, Ifako, Igbo-Alejo, Inuegbe, Tomaro, Akaraba, Igbo-Iu, Okonta, etc. The major occupation includes fishing, farming, trading etc. The general land use in the study area is as shown in Fig 2. Information from the 2003 Landsat ETM+ image showed that the predominant land cover of the study area is built up. The built-up area covers about 39.8 % (5352.65 ha of the total 13459.49 ha) of the total land use. The built-up areas in the classification consist of buildings as well as bare ground. The high forest covers 7.8 % (1052.44 ha), while the light forest covers 10.6 % (1427.61 ha). About 3379.29 ha (25.1 %) and 2247.5 ha (16.7 %) is covered by water body and utilities respectively (Fig 3). The length of the pipeline is 11.851919 km while the digitized road network covers 56.545 km. The road network criss-crossed the built up areas in the north of the study area, perhaps to overcome the transport problem that could be associated with the riverine communities. An important island in the LGA is Ilado Island that is made up of some communities. The island is linked with others including the Tin Can Island (where the Tin Can port is situated) – which is Nigeria’s busiest port, by the bridges. Settlements in Ilado Island are not accessible; leaving only speed boats and canoes as only viable means of accessibility.  Fig 1: A 2002 Landsat ETM + of Amuwo Odofin LGA, as an insert in the Map of Lagos State in Nigeria  Fig 2: A 2002 Landsat ETM + classified image of Amuwo-Odofin LGA, showing the distribution of the land use types in the area  Fig 3: Area extents of the land cover in Amuwo – Odofin LGA, Lagos State, Nigeria (Source: Extracted from Landsat ETM+ 2002) Material and Methods Sampling design, collection and field observations The study was primarily conducted using the 2002 Landsat ETM + and 1:25,000 topographical map of the study area. A handheld Global positioning system (GPS) (Magellan model; accuracy level = ± 10m) was used to identify the coordinate of obvious (well dispersed) benchmarks as training samples for geo- referencing and identification on the satellite imageries that has been acquired. From the satellite imagery, a subset of the study area was extracted from the original satellite image. Subset extraction, spectral enhancement and georeferencing were done using the Erdas Imagine (9.2) and ArcGIS (9.2) software. Using the Erdas Imagine, a false colour composite (FCC) was created to increase the contrast of the image in order to obtain better spectral resolution, Erdas Imagine 9.2 and ArcGIS software were used. Supervised classification was done using the maximum likelihood algorithm. The parametric method was used as a decision rule where it operates in a continuous decisions space which allows the entire pixel on an image to be identified. Five broad land cover classes were identified. They are vegetation, water body, settlements, utilities and bare ground. These features of interest were then extracted from the image by digitizing. Spatial analysis was performed using the ‘buffer operation’. ‘Buffer operation’ was used to determine the topology and proximity of the pipeline to other land uses. The buffer operation creates a new polygon data set, where a specified distance is drawn around specific features within a layer. The distances varied based on the stipulated attribute values. For this study, buffer zones were created at 25 m, 50 m, 100 m and 500 m around the pipeline. This was overlaid by the vector map layer containing the cartographic database of the selected communities in the studied LGA. The results of the overlay operation of the vector based cartographic (location) database on the result of the buffer operation were used to determine the extent of the vulnerability of the settlements in the oil pipeline corridor. In addition, the suitability analysis inherent in ArcGIS 9.2 was used to determine the appropriate range of the Right of Way (ROW) to be located for effective monitoring of oil pipelines. This is expected to be useful in providing a geo-spatial database for monitoring of oil pipelines. This was done using the query builder. In this study, ‘0’ was used to connote ‘not suitable’ and ‘1’ for ‘suitable’. The results were presented in map and table forms. Results and Discussion This investigation was aimed at mapping the oil pipeline in Ilado area of Amuwo-Odofin LGA of Lagos to determine the settlements that are at risk and vulnerable to pipeline related disasters. An analysis of the 2003 Landsat ETM+ image of the area showed that some settlements in the LGA lie within the pipeline corridor, making them vulnerable to fire disaster and associated problem during oil spill and / or explosion. At 25 m within the pipeline corridor, Inuegbe settlement was vulnerable (Fig. 4a). The spatial analysis revealed that this settlement gradually encroached on the pipeline ROW placed by the government. The Inuegbe was also the first and worse affected by the oil pipeline explosion in 2006, among the communities in the LGA. During this period, a number of people, farmlands, mangrove vegetation and aquatic life suffered. Aquatic lives such as fishes and periwinkles, which were usually a vital source of income to residence of Ilado communities, were destroyed. Similarly, oil spillage causes oiling stress in the environment (Ewa-Oboho, 1988; 1994).. In addition, the result of the vegetation cover analysis revealed that light mangrove vegetation is predominant within 500m radius of the oil pipeline (Table 1). This position was validated with a field survey. It was observed that light forest is the vegetation type found around the pipeline as well as farmlands. Most of the residences in the settlements have their farmlands around the oil pipeline. Some of these farmlands have encroached on the ROW. The presence of light forest and farmlands in a previously dense mangrove forest suggests that the original vegetation has been degraded, with the antecedent consequences (e.g. Adesina, 1989; Ekanade et al., 1996; Salami, 2001).  Fig. 4: Results of the ‘overlay’ of the vector cartographic database and the buffer zones, within (a) 25, (b) 50 and (c) 100 and 500m of the pipeline corridor in Amuwo –Odofin LGA, Lagos, Nigeria  Conclusions and Recommendations This study has chosen to demonstrate the use of a geospatial technology to provide decision support information for oil pipeline prone disaster monitoring and management. This study has used Erdas Imagine ArcGIS software to do this. The objectives included the mapping and characterization of the settlements that were close to the pipeline corridor in Amuwo-Odofin LGA in Lagos Sate; creating spatial databases for the management of oil pipelines in the study area; and demonstrating data manipulation, retrieval and other spatial analyses, with the view of providing spatial decision support information. The study has shown that the pipeline is exposed; and made vulnerable to vandalization and that some of the settlements have intruded into the pipeline corridor, making them vulnerable. A decisive application of geoinformation technology, for example, the suitability analysis carried out on the study area clearly showed that Inuegbe settlement is not suitable in its present location, having extended to 25 m of the pipeline corridor (Table 2). The presence of this settlement and farming activities within the pipeline corridor further suggested that the pipeline will still be vulnerable to vandal attack. Although it was reported by the residence that a Police Post exist in this settlement, it is not evident that this could stop the vandalization of the oil pipeline as well as the resultant fire. Field study also revealed that the pipeline was still being vandalized as at the time of this study as evident in a number of hollows, containing oil (Fig 2b) exist few meters away from the pipeline. In addition, the terrain where the oil pipeline in Ilado is located is not accessible by road. It is only accessible by speed boat, and this could pose a challenge for efficient monitoring by the officials of responsible organisation. This may not be same for vandals, who are likely pirates or used to movements along the coastlines. Again, although there is a Police Post in Inuegbe (the closest settlement to the pipeline) the vandalization of oil pipeline was not prevented. It is therefore recommended that the ROW should be adequately monitored and prevented from use for farming activities and the likes. Such corridor should also be monitored by heavy security. This should also be implemented in places where activities of vandals have posed a high security risk. Finally, it is recommended that the residences of Inuegbe and other settlements that pose such ecological risk be relocated to a safe environment. Table 2: Suitability Analysis of the showing the extent of the investigated settlements within the oil pipeline corridor in Amuwo-Odofin LGA, Lagos State, Nigeria  Note that ‘buffer distance’ is in meters |