scholarly journals Geotechnical evaluation of gully erosion and landslides materials and their impact in Iguosa and its environs, southern Nigeria

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Godwin Okumagbe Aigbadon ◽  
Azuka Ocheli ◽  
Ernest Orji Akudo
Keyword(s):  
Human Activities ◽  
Internal Resistance ◽  
Liquid Limit ◽  
Soil Samples ◽  
Steep Slope ◽  
Mitigation Measures ◽  
Drainage Systems ◽  
Coefficient Of Permeability ◽  
Southern Nigeria ◽  
Geotechnical Evaluation

Abstract Background Detailed field surveys and geotechnical evaluation of soils in Iguosa and its environs, Southern Nigeria, were undertaken to determine the root causes, mechanisms, and impacts of landslides and gully erosion. This was done to suggest appropriate mitigation measures to reclaim the affected land and prevent future occurrences in the study area. Results Field study revealed high elevations, a steep slope, high rainfall and inadequate drainage systems. Also, human activities and socio-cultural activities have contributed to the large lateral extents in depths and widths of the landslides and gullies in the study area. The geotechnical analyses reveal that soil samples from SB1, SB2, SB6 and SB7 lithological units are mainly sandy clay with a coefficient of permeability ranging from 3.5 × 10−4 to 4.2 × 10−4 cm/s, the cohesion ranges from 27 to 28 kƿa and angle of internal resistance ranges from 27° to 30° respectively. The plastic limit ranges from 2 to 4, and liquid limit ranges from 33 to 38, and the plasticity index ranges from 30 to 36. Ajali sand units SB3, SB4, SB8 and SB9, consist of coarse-grained sand with no plasticity. The coefficient of permeability ranges from 2.8 × 10−4 to 3.2 × 10−4 cm/s, the cohesion range from 10 to 18 kƿa, angle of internal resistance 24° to 26°, respectively. The soil samples from SB5 and SB10 lithological units are silty-clay with a coefficient of permeability of 4.6 × 10−4 to 4.8 × 10−4 cm/s. The cohesion of 45 to 46 kƿa, and angle of internal resistance of 37° to 40°, respectively. The plastic limits ranges from 35 to 36, and liquid limit is 76, and the plasticity index ranges from 40 to 41. Conclusion Field survey and geotechnical evaluations of the soils revealed that high elevation, a steep slope and the geotechnical properties of the soils were the initial conditions that initiated landslides and gully developments in the study area. This has also been influenced by rainfall, poor vegetation, inadequate drainage systems, and human activities as well as socio-cultural activities. Over four hundred and thirty-two houses and farmlands and other properties have been damaged and abandoned in the study area. Covering the landslide areas with impermeable layers/materials, diverting surface water away from the landslide areas, enacting laws to prevent the erection of structures on landslide prone-areas, sound drainage systems, the use of biotechnical slope and bioengineering methods, afforestation and re-vegetation were the proposed mitigation measures to tackle this menace in the study area.

Geotechnical Evaluation of Gully Erosion and Landslides Materials and their Impact in Iguosa and its Environs, Western Anambra Basin, Nigeria.

2021 ◽  
Author(s):  
Godwin Okumagbe Aigbadon ◽  
Azuka Ocheli ◽  
Ernest Oji Akudo
Keyword(s):  
Internal Resistance ◽  
Liquid Limit ◽  
Gully Erosion ◽  
Slope Instability ◽  
Geotechnical Parameters ◽  
Anambra Basin ◽  
Landslide Hazards ◽  
High K ◽  
The Mean ◽  
Geotechnical Evaluation

Abstract Background: Field survey and geotechnical evaluation was done to determine the soil characteristics of the gullies and landslides materials and their impact in Iguosa and its environs, Western Anambra Basin. This was done to explain and evaluate the root problems, causes, mechanism of the continuous gullies and landslides in the study area.Results: The field study reveals that the geomorphological characteristics, weakly developed structures, slope steepness, wrong use of the land and poor vegetation cover coupled with intense and prolonged rainfall contributed to the origin, causes of gullies and landslides in the study area. Geotechnical parameters for soil samples in the study area shows that the mean liquid limit (LL) of 40, mean plastic limit (PL) of 8.30, mean plasticity index (PI) of 21.20, mean coefficient of permeability (K) of 3.65 × 10cm/sec, mean cohesion and mean angles of internal angles between grains of 2.56 kƿa and 23.70 respectively. The low PL, low LL and low PI values of the Ajali sand, low cohesion (poor compaction) and low angle of internal resistance between grains of the soil, high K of Ajali sand coupled with the swelling and shrinking nature of the clay beds beneath the Ajali sand, resulted to easily weathering of the Ajali sands, erosional and continuous landslide activities in these affected areas.Conclusions: The origin, mechanism and impacts of landslide hazards have been investigated in Iguosa and its environs, Western Anambra Basin, Nigeria. Field observation reveals that the geomorphological characteristics, weakly developed structure, high slope instability, wrong use of land, as well as the steepness of the slope and intense and prolonged rainfall contributed to the origin of landslide as well as the gully erosion in the study area. The unconsolidated nature of the soil, less cohesion, high permeability, and weak plasticity of the soil that occurs under and above the clay lithologic units (gliding planes) contributed to landslide and gully erosion. Possible prospective implications of the gully erosion and landslides in the study areas are land degradation, destruction of houses and other properties, farm lands and roads. The following suggestions have been made to solve these problems by covering the landslide areas with impermeable layers/materials, diverting surface water away from the landslide areas, enacting laws to prevent erection of structures on landslide prone areas, the use of biotechnical slope techniques and bioengineering methods. The application of these recommended methods will go a long way in solving the problem of landslide hazards in the study area.

scholarly journals THE OLVIOS, RETHIS AND INACHOS DRAINAGE SYSTEM EVOLUTION AND HUMAN ACTIVITIES INFLUNCE OF THEIR FUTURE EVOLUTION

2017 ◽  
Vol 43 (2) ◽  
pp. 548 ◽  
Author(s):  
Th. Anagnostoudi ◽  
S. Papadopoulou ◽  
D. Ktenas ◽  
E. Gkadri ◽  
I. Pyliotis ◽  
...  
Keyword(s):  
Coastal Area ◽  
Human Activities ◽  
Drainage System ◽  
Physical Factors ◽  
Drainage Systems ◽  
System Evolution ◽  
Corinth Gulf ◽  
Future Evolution ◽  
Tectonic Regime ◽  
Flow Element

Olvios, Rethis and Inachos Rivers are multistory drainage systems that occur in Northern Peloponnesus, and at the present day they have and a reversed, North to South, flow element. Dervenios, Skoupeikos and Fonissa Rivers are the misfit streams of Olvios and revealed as juvenile streams and discharge to the Corinth gulf. Agiorgitikos River is the misfit stream of Rethis River and Seliandros River is the juvenile stream. Asopos, Nemeas and Rachiani Rives are the misfit streams of Inachos River and they also discharge to the Corinth gulf. Asopos River characterized as re-established stream. Physical factors such as tectonic regime (active and inactive faults), lithology, erosion and distance from the source influenced the three drainage systems evolution and could be influence them also in the future. The increase of human activities both in their southern parts and in the distal parts close to the coast could be change the physical evolution of the studied drainages, producing a new wind gap in the coastal area and a lake or a lagoon backwards of the coastal area, destroying villages and towns.

scholarly journals Appraisal of Geotechnical Characteristics of Ormara Soil, Baluchistan, Pakistan

2019 ◽  
Vol 10 (3) ◽  
pp. 22-26
Author(s):  
Abdul Jabbar Khan ◽  
Naveed Ahsan ◽  
Muhammad Sanaullah ◽  
Gulraiz Akhter
Keyword(s):  
Triaxial Compression ◽  
Liquid Limit ◽  
Soil Samples ◽  
Engineering Properties ◽  
Clay Layer ◽  
Compression Tests ◽  
Geotechnical Characteristics ◽  
Density Values ◽  
Construction Plans ◽  
Triaxial Compression Tests

Ormara is located 240 km west of Karachi which is a coastal and port city (25° 16' 29N, 64° 35' 10E) ofPakistan. Present study evaluates engineering properties of soils of Ormara for future construction plans and possibleexpansions in the area. Fifty bore holes were done in study area at depths of 20m, 40m and some (10 bore holes) were60m deep. The study area was divided into three major zones i.e. Foot hills, on-shore and off-shore. Groundwater wasencountered at depths of 2.75m on onshore and offshore zones and at 3.65m depth in foothill zone. Laboratory testingi.e. moisture content (12 to 38 %), liquid limit (from 26 to 34), plasticity index (10 to 18) of soil samples indicate thatsoils are low plastic to moderate plastic in nature. Soil samples of granular soils indicate angles of internal friction (ø)varying from 260- 36ºin upper sand layers while 260 to 30º in lower silt layers (encountered after the clay layer) andCohesion ranges 0 to 0.04kg/cm2 in all three zones. Further, unconsolidated undrained triaxial compression tests on aclayey soil sample indicated an undrained cohesion value of 28 kPa. Density values ranges from 1.6 to 2.05gm/cm3.Consolidation (Cv = 0.20 to 0.40 cm2/minute, Cc = 0.149 to 0.17) has been calculated for clay layer. Chemical testscarried out on soil samples indicated that soil and water both are reactive aggressively and may cause corrosion to steeland concrete disintegration.

Managing the Impacts of Human Activities on Fish Habitat: The Governance, Practices, and Science

2015 ◽  
Keyword(s):  
Human Activities ◽  
Habitat Management ◽  
Fish Habitat ◽  
Risk Assessments ◽  
Mitigation Measures ◽  
Policy Makers ◽  
Habitat Features ◽  
Science Advice ◽  
Governance Practices ◽  
Management Approaches

<em>Abstract.</em>—The landscape for policy and management of fish habitat is changing. The historic focus on evaluating environmental impact assessments for large projects, and issuing (or not) permits for small projects is being supplanted by new expectations for habitat managers and policy makers. Many of these new expectations are rooted in the adoption of an ecosystem approach to management of diverse human activities, including fisheries, in aquatic ecosystems, combined with a growing emphasis on integrated management of those human activities, in turn aided by spatial planning and spatial management approaches in many fields. These new expectations placed on habitat managers and policy makers create the need for expanded support from a new blending of habitat and population sciences. Historically, it may have been sufficient to use science advice based on relative indices of habitat quality and carefully assembled expert opinion as the basis for many tasks in habitat policy and management. Such tools now must be augmented by much more quantitative science advice, to allow for setting operational objectives for managing habitats, assessing the quality and quantity of critical or essential habitat for protected or exploited fish populations, conducting risk assessments of projects and mitigation measures, making siting decisions about marine protected areas and other spatial zoning measures, and many other tasks in which habitat managers and policy makers must participate. Science advice now must be able to quantify the relationships between habitat features and population status and productivity, as well with community properties such as resilience and vulnerability. This advice has to capture the uncertainty in the relationships and data sources, in forms that fit comfortably into risk assessments. Tools for forward projection of the habitat consequences of management options are needed, as are tools for cost-benefit analyses of tradeoffs among different types of habitats for different groups of aquatic species. None of these analytical challenges is beyond the scope of modern statistical and modelling capabilities, and current ecological concepts. Few of them can be met by existing tools and data-bases however. Moreover, many of the conceptual approaches to aquatic habitat management have been imported from terrestrial habitat management. They may have served adequately for management of riverine and marine benthic habitats, but some of the fundamental conceptual starting points are being questioned for marine and lacustrine habitats more generally. The paper brings out both some promising opportunities and some difficult challenges for the science needed to support contemporary habitat management and policy.

scholarly journals Management of erosion hazard with the agro technology in watershed aie limau kambiang on the upper watershed tarusan

2018 ◽  
Vol 229 ◽  
pp. 04016
Author(s):  
Aprisal ◽  
Bambang Istijono ◽  
Reski Permata Sari
Keyword(s):  
Soil Erosion ◽  
Random Sampling ◽  
Soil Loss ◽  
Plant Density ◽  
Surface Flow ◽  
Soil Samples ◽  
Steep Slope ◽  
Soil Infiltration ◽  
Infiltration Capacity ◽  
Soil Loss Equation

One of the hazards of the erosion is soil infiltration capacity is decreased in the place of occurrence of erosion and increasing the volume of surface flow. It will also lead to the occurrence of the superficiality of the river due to the deposition of materials of soil erosion. These hazards need alternative agrotechnology which could reduce the rate of soil erosion. This research is to know the hazard of soil erosion in the upper watershed of the Aie Limau Kambiang and find out the alternative agrotechnology for reducing the soil erosion. This research was conducted. Soil samples collected was taken in purposive random sampling based on a unit of land. The data were analyzed using the universal soil loss equation. The research results of the largest erosion threat come from the land use of traditional gardens and plant density is low. The highest erosion 151,012.00 ton/ha/year was founded on the plantation blended that have a steep slope over 35% LS value of 9.5. The better of agrotechnology with increasing plant density, that could reduce erosion to 503.40 ton/ha/year. This means that the hazard of soil erosion could be controlled with land management and selected of the better agrotechnology.

scholarly journals Possibility of use Artemisia austriaca Jacq. as an indicator of environmental pollution by certain heavy metals

2020 ◽  
Vol 10 (1) ◽  
pp. 24-39
Author(s):  
Yulia M. Kanibolotskaya
Keyword(s):  
Heavy Metals ◽  
Plant Communities ◽  
Human Activities ◽  
Negative Impact ◽  
Weather Conditions ◽  
Active Species ◽  
Soil Samples ◽  
Anthropogenic Factors ◽  
Industrial Enterprises ◽  
State Of The Environment

Due to the increasing negative impact of anthropogenic factors on the state of the environment in man-made regions, the possibility of using Artemisia austriaса Jacq. as an indicator of contamination of industrial areas by some heavy metals and transformation of plant communities under the influence of human activities is being considered. In order to achieve the objective of the study, the content of heavy metals (Ti, Mn, Cr, Fe, Ni, Cu, Zn, Pb, Sr); in plant metals (A. austriaса) and soil samples selected in the suburbs of Pavlodar and Aksu (Pavlodar region, Kazakhstan) is analyzed at different distances from existing industrial enterprises. Geobotanic studies have also been carried out (using classical methods). A. austriaca, being a digressive-active species, under human-induced conditions often becomes a dominant or subdominant in plant communities (in regions where it has historically been represented in little abundance). Therefore, its capacity to accumulate some heavy metals (according to our research results – Zn and Cr) can be used (taking into account the distance from the source of emissions, age of plants, features of nanorelief and weather conditions) to determine the presence of contamination of industrial (or adjacent) areas, especially in areas of operation of metallurgical enterprises.

scholarly journals Geotechnical Characterization of soils for Use as Landfill Liner: A case study of soil samples from the Paynesville Sandstone and Farmington River Formation, Liberia

2018 ◽  
pp. 70-75
Author(s):  
Y. C. Baysah ◽  
R. S. Ngumbu ◽  
A. K. Fayia ◽  
A. S. Moore ◽  
J. T. Toe Sr ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
Waste Management ◽  
Liquid Limit ◽  
Soil Samples ◽  
Natural Material ◽  
Sanitary Landfill ◽  
Landfill Liner ◽  
Mean Values ◽  
Healthy Environment ◽  
Geotechnical Investigations

In Liberia, waste management is one of the main challenges faced by municipal authorities, environmental technicians and public health practitioners in their quest to maintain a clean, safe and healthy environment. The construction and operation of a sanitary landfill ensures adequate waste management and, by extension, the protection of both the environment and human receptors. This study presents the results of geotechnical investigations conducted on soils from two sedimentary units of Liberia: Paynesville Sandstone and Farmington River Formation. The intent of the study was to assess the suitability of the soil for use as landfill liner. Three soil samples were collected from each of the two sedimentary units and, using B.S 1377 (1990), soils characteristics such as particle size distribution, permeability, liquid limit, plastic limit, plasticity index and hydraulic conductivity were measured and presented as mean values. Hydraulic conductivity of a sanitary landfill liner is the most important parameter to consider in materials selection. The results of hydraulic conductivity obtained from the study showed that only the samples from Farmington River Formation met the USEPA (1994) and CGRM (2007) requirement of ≤ 1x10-9 m/sec suitable for use as landfill liner. The mean soil permeability results for the Paynesville Sandstone and Farmington River Formation were 2.5 mL/hr and 0.05 mL/hr respectively; implying that the samples from the Paynesville Sandstone are more permeable and, thus, more susceptible to leaching and groundwater contamination if used as a bottom liner in a landfill design. Based on the findings of this research, it can be concluded that the sample from the Farmington River Formation is more suitable for use as a natural material for landfill liner. The quality of the sample should, however, be improved by addition of small amounts of bentonite.

scholarly journals Implementation of Artificial Neural Network to Predict the Permeability and Solubility Models of Gypseous Soil

2021 ◽  
Vol 29 (1) ◽  
Author(s):  
Imad Habeeb Obead ◽  
Hassan Ali Omran ◽  
Mohammed Yousif Fattah
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Prediction Models ◽  
Soil Samples ◽  
High Rate ◽  
Soil Behavior ◽  
Coefficient Of Permeability ◽  
Artificial Neural ◽  
High Level ◽  
Gypseous Soil

The objective of the present study is to make a database that describes the leaching-permeability behavior of collapsible gypseous soil. The data will be implemented to develop ANN prediction models for predicting the saturated coefficient of permeability and percentage of solubility by weight. The complex soil behavior and tedious and time consume in soil testing have driven researchers to use Artificial Neural Network (ANN) as tool for prediction. The objectives of the study were to investigate leaching-permeability behavior of collapsible gypseous soils and to develop ANN models for estimating the saturated coefficient of permeability and solubility of the soils. The MATLAB R2015a software was used to predict the saturated coefficient of permeability and the solubility percentage by weight of gypseous soils. The dataset used in this work included (513) records of experimental measurements extracted from leaching-permeability tests conducted on gypseous soil samples taken from Baher Al-Najaf in Iraq. Four input variables were investigated to have the most important influence on the permeability and solubility percentage by weight. According to the achieved statistical analysis, the ANNs model have a reliable capability to find out the predictions with a high-level of accuracy. The gypseous soils exhibited a high rate of dissolution of soluble minerals content, which caused increase in the coefficient of permeability as the soil samples reach the state of long-term full saturation.

scholarly journals Land Use Activities and Their Effects on Soil Erosion on the Slopes of Kajulu Hills, Kisumu County, Kenya

2019 ◽  
Vol 11 (2) ◽  
pp. 68
Author(s):  
Otieno, J. ◽  
Otieno, A. C. ◽  
Tonui, K. W
Keyword(s):  
Land Use ◽  
Soil Erosion ◽  
Human Activities ◽  
World Wide ◽  
Arable Land ◽  
Mitigation Measures ◽  
Natural Phenomenon ◽  
Mountainous Regions ◽  
The World ◽  
The Hill

Soil erosion is a natural phenomenon, but human activities accelerate it between ten to forty times the natural occurrences. It therefore calls for mitigating measure to curb the effects of erosion since soils form at a slower rate than they are destroyed. A study on land use activities and their effects on soil erosion was conducted in the upland ecosystem in Kenya, Kajulu hills. The study assessed the effectiveness of the mitigation measures adopted by the residents to ease the effects erosion on the hill slopes. A sample size of 295 households out of 1600 households engaged in various mitigating practices was used. The study collected data on the magnitude of soil (kg) lost from the arable lands using collector ditch technique. The data were analyzed using frequency distribution tables and Man U-test. The result showed a double amount (1.198kg/m2) of soil lost on the arable land without mitigation measures as compared to plots under cut off ditches (0,615kg/m2) and vegetative strips (0.904kg/m2) with Man U=7. These findings were above the world wide estimation of soil erosion on arable mountainous regions which range between 1.3-40.kg/m2/year (13-40T/Ha/year) as it was based on one rainy season.

scholarly journals GEOTECHNICAL INVESTIGATION OF PAVEMENT FAILURE; CAUSES AND INHERENT SOLUTIONS FOR SUSTAINABLE HIGHWAY CONSTRUCTION IN SUB-SAHARAN AFRICA

2020 ◽  
Vol 35 (4) ◽  
pp. 103-114
Author(s):  
Omowumi Ademila ◽  
Abel Idowu Olayinka
Keyword(s):  
Clayey Soil ◽  
Triaxial Compression ◽  
Road Construction ◽  
Liquid Limit ◽  
Soil Samples ◽  
Sub Saharan Africa ◽  
High Plasticity ◽  
Coefficient Of Consolidation ◽  
Geological Investigation ◽  
Undisturbed Soil

Engineering geological investigation of some unstable and stable sections of the Ibadan-Iwo-Osogbo highway was undertaken to unravel the intrinsic reasons responsible for continuous pavement failure along this road. Eighty disturbed and forty undisturbed soil samples were collected at different depths from twenty test pits of six selected failed sections (FS) and two stable sections (SS). Road construction analysis was done on these soil samples using standard methods. Liquid limit (22 - 64% and 32 - 40%), plasticity index (13 - 41% and 12 - 18%) and percentage fines (47 - 59% and 32 - 41%) indicated fair to poor and fair to good subgrade materials of FS and SS respectively. Medium to high plasticity and high clay content of soils of FS are indicative that the soils possess medium to high swelling potential. The activity of clay in soils of FS was approximately 0.3 – 1.2 and classified as inactive to normal clay. High linear shrinkage (> 10%), low compacted density and predominance of fines in soils of FS caused the instability. Exposure to excessive moisture led to strength reduction of the soils. Triaxial compression showed cohesion (72.6 - 127.0 kN/m2) and internal friction (12.7° - 33.3°) indicating moderate to good shearing strength of the soils. A coefficient of compressibility of 0.1 – 0.5 kN/m2 indicated incompetency of the soils for road construction and the coefficient of consolidation was 0.01 – 0.30 m2 /year. The subsoil of the FS is impervious with a relatively low coefficient of permeability, indicative high saturation in the region. Thus, the pavement failure was caused by water absorbing clayey soil, poor geotechnical parameters of the soils and a poor drainage network.

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