Seasonal Variations in Heavy Metal Status of the Calabar River, Cross River State, Nigeria

The study examined heavy metal status of the Calabar River in Cross River, Nigeria. Surface water samples were collected during the wet and dry seasons for ten months across five stations and analyzed for heavy metal parameters using standard methods. Result showed that the concentrations of iron (Fe), zinc (Zn), manganese (Mn), copper (Cu), lead (Pb) and total hydrocarbon (THC) in the dry and wet seasons were low and within WHO and FEPA tolerable limits The proportion of copper (Cr), cadmium (Cd), barium (B), nickel (Ni), vanadium (V) and mercury (M) were not detected indicating the absence of these metals in the sampled stations. The low levels of heavy metal contents across the sampled stations showed they were not polluted and as such suitable for aquatic live. Independent samples test result indicated seasonal difference in the proportion of Fe, Zn, Cu, Pb and THC (p<0.01).The study identified runoff from industrial, agricultural and residential areas as sources of heavy metal pollution in the wet season and effluent discharges from industrial and municipal wastes as major sources of pollution of the Calabar River in the dry season. To sustain the ecological status of the Calabar River, waste management practice of waste re-use through the use of retention ponds is encouraged

Sediment Loss Responses to Rainfall on Different Surfaces in Obudu, Cross River State, Nigeria

The amount of runoff generated relative to different surface types given an amount of rainfall is very important in hydrogeomorphological studies. This study is aimed at examining sediment yield responses to rainfall on different surfaces in Obudu, Cross River State, Nigeria. Data were collected on rainfall amount, intensity, duration and sediment loss from three run off plots on natural vegetation surface, mulched and bare surfaces. The data collected were analyzed using Pearson’s moment correlation and multiple regression statistical techniques. The results revealed that rainfall amount correlated positively with sediment loss on vegetated, mulched and bare surfaces with r-values of 0.58 (p<0.01), 0.57 (p<0.01) and 0.95 (p<0.01) respectively. Rainfall intensity correlated positively with sediment yield on the vegetated, mulched and bare surfaces with r-values of 0.75 (p<0.01), 0.65 (p<0.01) and 0.60 (p<0.01) respectively. The negative correlations between rainfall duration and sediment loss suggests that sediment loss decreases on all the surfaces considered with r-values of - 0.15 (p<0.01), - 0.21 (P<0.01) and -0.06 (p<0.01) on vegetated, mulched and bare surfaces respectively. The study further revealed that the predictive variables explain 62.7%, 50.8 and 60.8% of sediment yield on bared, vegetated and mulched surfaces respectively as rainfall directly influences sediment loss, though the importance of surface types cannot be discarded

Spatial Variability of Soil Properties in the Obudu Mountain Region of Southeastern Nigeria

Abstract This study examined the spatial variability of soils in the Obudu Mountain regions of southeastern-Nigeria. Data for this study were obtained from direct field measurements, topographic maps and laboratory analysis of the area. Twelve soil samples were collected from six topographic gradients (2.5, 27.5, 22.5, 17.5, 12.5 and 7.