Socio-economic implications and environmental effects of oil spillage in some communities in the Niger delta
This study examined the effects of oil spillage on the socio-economic activities of the people and the environment in some communities in the Niger delta. The objectives are to determine the quantity of oil spilled from pipelines, the area of coverage and to assess the effects of oil spillage on the people, soil and water. Data were collected from both primary and secondary sources. The primary data relied on the administration of structured questionnaires; 319 questionnaires were randomly distributed to a sample population (household heads), with 302 retrieved. Secondary data were sourced from published materials. Also, soil samples from four locations and water samples from five locations were collected to determine the pH value of the water, the presence and concentration of heavy metals in the soil and the total hydrocarbon content (THC) of water. Soil and water samples were analysed using the atomic absorption spectrophotometer and gravimetric methods for soil and water, respectively. There was a strong relationship between the volume of oil spilled and the area coverage. Laboratory soil analysis from sampled communities showed a higher concentration of heavy metals (chromium, lead, arsenic, etc.) above the World Health Organization (WHO) permissible levels as well as the figure for controlled site. Similarly, three of the communities studied had THC concentrations of 40,000 ppm exceeding both WHO limit of 1 ppm and controlled site. This has grave implications on the soil, water and socio-economic activities of the people. It is, therefore, important that environmental laws should be strictly adhered to. Compensation should be adequately and promptly paid to the communities, and remedial action should be speedily undertaken whenever there are spills. Finally, the oil companies must involve the communities in the maintenance and monitoring of pipelines with the ultimate goal of improving the quality of life of members of rural communities.
Agro-Ecosystem Diversity in Petroleum and Natural Gas Explored Sites in Assam State, North-Eastern India: Socio-Economic Perspectives
The discovery of oil, drilling of oil wells and exploration of fuels from underground reserves and their transportation has a long worldwide history. As collateral for this, accidents of oil tankers and leakage of pipelines, oil spills and infiltration into the sites of explorations, forest and agriculture lands have accompanied oil production. Its visible impact on agriculture productivity has been observed and explored in different parts of the world, including the biodiversity hotspots of the Indian subcontinent. The degraded land becomes barren and unsuitable for the cultivation of cereal crops for longer periods of time. Cereal and horticultural crops are more sensitive and cannot be grown in such inhospitable soil; therefore, alternative energy crops are fit and efficient substitutes on such degraded land.
Design of reinforced concrete lining in pressure tunnels, considering thermal effects and jointed rockmass
Abstract Jaeger's theory (Jaeger, Rock Mechanics and Rock Engineering , Cambridge University Press, 1972) of the design of the lining for a pressure tunnel applies to a tunnel located in an isotropic, homogeneous and elastic medium. The theory is derived from the elasticity equations for the plane stress condition. In this paper, Jaeger's theory is extended to a plane strain situation. Also included is a discussion of the effects of a uniform increase (or decrease) in the lining temperature, jointed rockmass, cracking of the tunnel lining, and cracking of the rockmass around the opening. Tables are presented for the modulus of subgrade reaction for various rockmass conditions and for rock sharing pressures for various lining conditions. The reduction factor to include the effect of joints in rockmass is derived by the analysis of a numerical model of the lined tunnel by the finite-infinite-interface element method.