The causes and impacts of the gully erosion menace in the Auchi community of Edo State, Nigeria, have been investigated. It was established that various factors bordering on anthropogenic and natural causes which include excessive rainfall, underlying geology of Auchi, nature of the soil at the affected sites, deforestation, practices by residents in the area that encourage run-off, lack of good drainage systems, absence of tangible erosion control measures by Governments at various levels, were major causes of the gullying in the Auchi gully sites; that have led to the death of several people and destruction of settlements and other facilities. But the natural causes of the gullying far outweigh the anthropogenic ones. Three methods of data collection were adopted in this study. These are the remote sensed data, data acquired from field observations and responses from questionnaires. Digital Elevation Model data was also used to delineate the boundary of the contributing watershed upstream of the site. After appraising the causes of gullying in Auchi and its impacts on the residents, recommendations which include adoption of concerted measures by Governments at all levels to address erosion menace in the area, enactment of relevant laws to discourage factors that promote erosion and expanding gullying in Auchi, putting in place specific reclamation measures, deliberate efforts by the relevant Federal Ministries to refill and construct a proper drainage system for the area that will be channelled to a safe discharge points down steam, among other feasible recommendations, have been proffered to curb the menace of gully erosion and its ravaging impacts on the community.
The empirical variation of earthquake parameters such as frequency, focal depth and energy had been used in the past by seismologists to estimate the magnitude of large historic earthquakes from existing intensity maps. The Engineering geologists often need it to predict the intensity, focal depth and energy of earthquakes on the basis of maximum possible magnitude for a certain return period. The generalized earthquake scaling relations derived by Gutenberg and Richter  were used to determine the intensity and earthquake energy of individual events. The following were investigated: Frequency-magnitude variation; Focal depth’s variation with intensity, magnitude and energy; Earthquake intensity’s variation with energy of earthquakes; Magnitude’s variation with intensity and energy of earthquakes.
The earthquake energy, intensity and magnitude decrease with increase in focal depth and maxima at shallow focal depth on the African plate.
The seismic energy radiated from the earthquake focus could be used as the earthquake magnitude and intensity predictor.
Most of the beaches are covered by vegetated sand dumps called sand dunes, built up through dry beach sand blown inland and trapped by plants and other obstructions. As sand accumulates, the dunes become higher and wider. Stable sand dunes play an important role to protect the coastline. They act as a buffer against wave damage during storms, protecting the land behind from salt water intrusion. This sand barrier allows the development of more complex plant communities in areas protected from salt water inundation, sea spray and strong winds. Plants play a vital role in this process, acting as a windbreak and trapping the deposited sand particles. A characteristic of these plants is their ability to grow up through the sand and continually produce new stems and roots as more sand is trapped and the dune grows. To form the sand dune in the coastal belt and their morphological characteristics always depends mostly on three conditions like supply of sediments, bearing capacity of air and plant covering. The present attempt is to explore the formation and morphological characteristics of coastal dune in the estuarine part with massive deposition of sediments throughout the year in the shore, presence of wide beach and off-shore wind through the vegetation processes estimation which may significantly helps the nature to prepare the coastal sand dune.
The study of hydrogeochemical processes using rare earth elements was carried out using water samples from weathered basement aquifers in Oban Massif and environs. A total of only 29 as number water samples were collected from boreholes, streams, springs and river sources. Physical parameters (pH, Eh, Ec, TDS and turbidity) were measured insitu using standard equipments. Anions (NO3-, SO42-, HCO3-, PO43-, Cl-) were measured in the laboratory using titration and chromatography, major cations (Mg2+, Ca2+, K+, Na+) were analysed using inductively coupled plasma argon emission spectrometry while the rare earth elements were assayed using inductively coupled plasma mass spectrometry. Speciation modeling for solution complexation and saturation indices was done using the software VISUAL-MINTEQ3.1. Results showed that low to medium pH(5.61-7.20) range and Fluorine mean value 20.08 ppm is common in the area which are not within WHO (2006) recommended values of 6.5-85 and 1.5 respectively for potable water. Rare earth elements exhibited very low values with exception of Ce (0.98 ppb), Gd (0.13 ppb), La (0.56 ppb), Nd (0.66 ppb), Pr (0.15 ppb) and Sm (0.11 ppb) that recorded appreciable concentrations compared to Dy (0.09 ppb), Er (0.05 ppb), Eu (0.02 ppb), Ho (0.02 ppb), Lu (0.011 ppb), Tb (0.01 ppb), Tm( 0.01 ppb) and Yb (0.04 ppb). Trilinear plot showed that the water type is dominantly Ca+Mg, Cl+SO4. Rare earth elements concentrations are within permissible limits for potable water. Light rare earth elements had dominance over heavy rare earth elements. Rare earth elements were higher in groundwater than surface water. The dominant complexing ligand in groundwater is Carbonato complex ligand (LnCO3)3 while surface water is dominated by free ionic REE species. Oversaturated rare earth minerals at S>1 are dominantly light REE phosphates (PO43-). In surface water both light and heavy rare earth elements minerals of phosphate ligand were supersaturated. Normalized rare earth elements to granite of Honkong and PAAS showed more enrichment of HREE. Two water types classified as recharge (type1) and discharge (type 2) were identified in the area. Rare earth elements levels are not toxic and within permissible level for potable water. Minor treatment of water to reduce acidity should be expedient and a research on bioavailability of REE in humans within the area is important.
Geo-spatial techniques play a vital role in hydrological investigations that are needed for proper management of drainage basins. This study aimed to determine and characterize tropical river basin for its suitability for diverse use and sustainable agro-economic development using the Jibwa catchment in Minna – Niger State, Nigeria as the region of interest. The data sets used includes: multi-date satellite imagery (Landsat TM 1987, Landsat ETM 2001), and the topographic map covering the study area at a scale of 1:50,000 from which the drainage network and contour were extracted. The hydro-basin was delineated and the output subjected to different hydro- morphometric computations using geo-spatial techniques and automated hydro geo-statistical GIS extensions. The result of this study showed that the Jibwa basin has a fourth-order dendritic stream network with a total of 173 streams and a drainage density of 1.42 per sq. km which indicates the presence of at least 2 streams per square kilometer of the study area. The average bifurcation ratio and slope of the basin is 5.26 and < 2% respectively. The study revealed the area to have adequate surface runoff which makes the area suitable for fishing, irrigation and an all year crop cultivation.