Crude Oil Spills: Effects on Soil Environment and Land Use Pattern in Acid Sand of Akwa Ibom State, Nigeria

Crude oil spills generate a lot of emotional outburst with, very often, some political undertones. Concerns over the soil environment and land use pattern of increasing oil spillage on land and wetlands have mounted with time since oil prospecting started in Nigeria. Crude oil spillage could result in a number ways. One of such is during the process of drilling an oil well when oil well blowout could occur. The other source of spillage is pipeline leakage or malfunction. This research therefore, aimed at assessing the effects of oil spills on the physical attributes of the soil as its effects the land use pattern in oil producing areas of Nigeria. The soil physical disruption of aggregates following spillage in the field is reflected in the reduced aggregate size and water stable aggregate in the soils. Before the spill, stable aggregates of < 2 mm recorded significantly high resistance to erosion. Whereas, the moment the spill occurred, some locations suffered 250% reduction, while some 14% and others 21%. However, increase in aggregates >2 mm after wet sieving increased the initial Mean Weight Diameter (MWD) by 50, 63, and 81% under, Ikot Udo, Ebe Ekpi and Esit Eket spill sites, respectively. As variations in water aggregates of the soil were recognised, the following results on the magnitude of stable aggregates to water were measured at the sites of recently spilled soils; the least class size (0.25 mm) of stable aggregate at Ikot Udo showed an increase of 3.7 percent stable aggregates, 3.5% stable aggregates were measured at Ebe Ekpi, and 3.2% stable aggregates at Esit Eket, relative to the control site. The fact that this granulated soils severely erode under intense storms that caused high runoff in control site suggests that spilled sites are more important in accentuating runoff by sealing the pore spaces by adsorbed oil and grease from the spills, which consequently decreased infiltration rate.