Anambra State of Nigeria is ravaged by ecological hazards of gully erosion and landslides. Over 450 active gully and landslide sites with depths ranging from 5 m to over 120 m are concentrated on both sides of the Awk...Anambra State of Nigeria is ravaged by ecological hazards of gully erosion and landslides. Over 450 active gully and landslide sites with depths ranging from 5 m to over 120 m are concentrated on both sides of the Awka-Nanka-Umuchu-Orlu cuesta. The Idemili River and Odo River form the major drainage basins of the area. The geomorphic characteristic of the cuesta/escarpment is a major controlling factor in groundwater recharge and discharge within the drainage basins. Rise in aquifer levels result in hydrogeotechnical implications of gully development and landslides. The calculated values of hydraulic properties of conductivity and transmissivity range from 1.20×10^-1 to 5.93×10^-1 cm/s and 1.15×10^5-13.05×10.3 m^2/s respectively. The values of groundwater velocity and groundwater discharge were 82 m.yearl and 2.96×10^6 m^3.yearl The plasticity index of the soil in the gully prone areas is relatively low ranging from 12.50-36.57%. The unique features of the geologic formations together with obtained aquifer characteristics favour gully/landslide hazards in the area.展开更多
文摘Anambra State of Nigeria is ravaged by ecological hazards of gully erosion and landslides. Over 450 active gully and landslide sites with depths ranging from 5 m to over 120 m are concentrated on both sides of the Awka-Nanka-Umuchu-Orlu cuesta. The Idemili River and Odo River form the major drainage basins of the area. The geomorphic characteristic of the cuesta/escarpment is a major controlling factor in groundwater recharge and discharge within the drainage basins. Rise in aquifer levels result in hydrogeotechnical implications of gully development and landslides. The calculated values of hydraulic properties of conductivity and transmissivity range from 1.20×10^-1 to 5.93×10^-1 cm/s and 1.15×10^5-13.05×10.3 m^2/s respectively. The values of groundwater velocity and groundwater discharge were 82 m.yearl and 2.96×10^6 m^3.yearl The plasticity index of the soil in the gully prone areas is relatively low ranging from 12.50-36.57%. The unique features of the geologic formations together with obtained aquifer characteristics favour gully/landslide hazards in the area.
