Erosion is a major problem, and, poses serious environmental hazards in many parts of anambra state, nigeria. Each type is associated with the progressive concentration of runoff water as it moves downstream. Pdf evaluating the stability of gully walls in agulu. Performance of gully erosion control measures in southeastern. Pdf an assessment and mapping of gully erosion hazards in. The study was conducted in agulunankaoko area within river odo catchment of southeastern nigeria. The gully, which began to form in the 1850s, is now approximately 1,100 square kilometers large. Water erosion of land surface is of two types namely sheet erosion and gully erosion. Nanka gully erosion the agulu nanka gully erosion has the potential for an ecological disaster, because the erosion causes frequent landslides. Application of groyne as a sustainable solution to agulunanka erosion problem the paper aims at highlights the natural and anthropogenic impact in gullyerosion geostructural failures. Nwajide and reijers 1996 and umeji 2003 studied the type locality and other gully sections, road cut exposures reference.
The nanka gully is part of the region of agulu within the nigerian state called ambra. These channels vary in size from small rills that can be backfilled to gullies large enough to seriously threaten the environment. Factor analysis of soil spatial variability in gully erosion. Application of groyne as a sustainable solution to agulu. A study into the effects of timely delivery of construction project on economic development of nigeria a case study of some selected project supervisors from julius berger nigeria plc and marlum nigeria plc, uyo offices. Geological, geotechnical, gully erosion, grainsize distribution, shear. Unfortunately, until now, most researchers are confined only to the factors causing gulling and control measures, keeping the losses sustained and other social and economic effects suffered by the affected people aside. The popular or infamous agulunanka gully erosion sites started from the head waters of streams and slopes of awkaorlu upland region. There is no significant relationship between the social and the economic effects of gully erosion in agulu nanka areas. Photo 1 urban gully erosion migrating along a constructed stormwater drain qld photo 2 rural gully erosion migrating through pastoral land sa. Crop yields have been reduced, thus creating problem in the green rev. The issue of gully erosion is of major concern in the southeastern part of nigeria. Palynology, source rock potential and thermal maturity of. The first is that present control measures are not entirely satisfactory in particular, a more detailed understanding of the mechanisms of different kinds of gullies is.
Ajaero and mozie 2011 in their assessment of gully erosion menace in agulunanka area reported that agulunanka gully erosion area represents a wide area being eaten away gradually and continuously by landslide cum gully advancement processes covering the entire aghori basin, which covers many communities in the region. Nwajide and reijers 1996 and umeji 2003 studied the type locality. Statistical analysis of variability in properties of soils in gully erosion sites of agulu nanka oko area, southeastern nigeria. Factor analysis of soil spatial variability in gully.
Oct 26, 2016 an assessment of the socioeconomic impacts effects of agulunanka gully erosion, anambra state, southeastern nigeria ea9cbd uploaded by 15projects oct 26, 2016 soil erosion is the systematic removal of soil including plant nutrients from the land surface by various agents of denudation. Implications of hydrogeophysical investigations of the agulu. General definition gully treatment is the stabilization of active gullies by vegetative or structural measures or a combination thereof. The first is that present control measures are not entirely satisfactory in particular, a more detailed understanding of the mechanisms of different kinds of gullies is needed so that treatments can be designed to suit. An assessment of the socioeconomic impacts effects of agulunanka gully erosion, anambra state, southeastern nigeria sold by ibitayo damaris principals management behaviour and examination malpractice in senior secondary schools. Gullies of about 120m depth and 2km width have been recorded in this area. Gully erosion is the process whereby runoff water accumulates and often recurs in narrow channels and, over short periods, removes the soil from this narrow area to.
The application of groyne modelplacement as sustainable solution which minimizes the control cost and guaranttees bed load as well as suspended load sediment. Archives vol 43 no 2 2007 articles statistical analysis of variability in properties of soils in gully erosion sites of agulunankaoko area, southeastern nigeria cc osadebe eg akpokodje doi. The incidence of gully erosion in agulunanka area of anambra state has assumed alarming proportions thereby gaining national recognition as an ecological. The aim of this study was to rehabilitate the gully erosion site and reduce longer term erosion vulnerability in agulunanka community. Gully erosion in the agulunanka region of anambra state. Pdf the agulunanka gully erosion menace in nigeria. Southeastern nigeria to study the gully patterns in relation to catchment characteristics. Gully erosion, the most impressive and striking erosion type, has been recognized as one of the major global environmental problems. A study on the effects of gully erosion on auchi settlement. This activity was carried out through some civil works such as construction of concrete drainage system, culverts and silty basin, spikes, rock chutes and stabilization of gully. Target oriented procedure for erosion control in the nanka. An assessment of the socioeconomic impacts effects of. Crosssection analysis shows that a nesw profile closely corresponds to the length of. Pdf 2014 scienceweb publishing evaluating the stability of.
Gully erosion, however, can also occur within a watercourse, typically within the upper reaches, and typically resulting from an active headcut migrating rapidly up the valley. This paper highlights the social and economic impacts of gulling in the area. Application of groyne as a sustainable solution to agulu nanka erosion problem. Agulu nanka, erosion, damages, gullies, socio economic life. What does the future hold for the population at risk. Geological and geotechnical studies of gully erosion at ekwulobia. Many states in nigeria are currently under the threats of this phenomenal process, southeastern part of the country being the most affected. Devastated landscape showing intercalation of red earth and unconsolidated whitish sand at nanka and oko gully sites.
Anambra is famous with its agulunankaoko ekwulobia gullies. It is a sequence of unconsolidated or poorly consolidated sand, 305m thick, underlain by. Gully erosion in the agulunanka region of anambra state, nigera. Implications of hydrogeophysical investigations of the agulunanka. The most active and dangerous spots occur at agulu, nanka, alor, oraukwu, oko and parts of udi, enugu and ukehe in anambra state. Nankaagulu axis is a major erosionhit area in the state, where gullies have taken. In the nanka community, ekentai in amako village, was reported to be a flourishing slave market during the period of the trafficking in human cargo and popularized by ezenwenwe. Sheet erosion is the removal of thin sheet of soil in an area while gully erosion is that which forms incised channels. The development of gully and other forms of erosion have become the greatest environmental problem facing the people of southeastern nigeria.
Erosion caused by concentrated flow begins where overland flow converges to channelized flow conditions. The popular or infamous agulu nanka gully erosion sites started from the head waters of streams and slopes of awkaorlu upland region. Probably the most notorious area of gully erosion in eastern nigeria is near the villages of agulu, nanka and oko in awka division, onitsha. The incidence of gully erosion in agulu nanka is not new, as it has formed a subject for research. Pdf an assessment and mapping of gully erosion hazards. An engineering design was used for the erosion gully intervention which. Evaluating the stability of gully walls in agulunankaoko gully. These areas happen to be the most ravaged by gully erosion. Unuehs institute for environment and human security climate change and migration. Anisotropic type determination and soil structure evaluation.
Gully erosion accelerates the loss of soil and decreases the productivity of agricultural land. Jan, 2014 findings are that the adverse social and economic effects of agulu nanka erosion on the residents in the erosion affected areas differ significantly from the social and economic situation in the unaffected areas and there is no significant relationship between the social and economic effects of gully erosion in agulu nanka areas. The genesis and location of this particular gully site on the landscape is similar to numerous other gully sites in the region. Modelling of gully erosion site data in southeastern nigeria. The impacts and implications of anthropogenic forces on. Findings are that the adverse social and economic effects of agulunanka erosion on the residents in the erosion affected areas differ significantly from the social and economic situation in the unaffected areas and there is no significant relationship between the social and economic effects of gully erosion in agulunanka areas. Five 5 gully locations and nine 9 gully profiles were selected for the investigation.
Ajaero and mozie 2011 in their assessment of gully erosion menace in agulu nanka area reported that agulu nanka gully erosion area represents a wide area being eaten away gradually and continuously by landslide cum gully advancement processes covering the entire aghori basin, which covers many communities in the region. Gis analysis of drivers of erosion and gullying in southeast. Statistical analysis of variability in properties of soils in gully erosion sites of agulu nanka oko area, southeastern nigeria cc osadebe eg akpokodje. Civil and environmental research issn 22245790 paper issn 22250514 online vol. The gully is situated on unconsolidated, friable, collapsible sandstones capped in some places by lateritic overburden. For example, 27 studied the agulunanka gully complex in anambra state southeast nigeria, they observed that the primary control of the gullies was the hydrogeological and. The science of the total environment, 53 1986 217232 217 elsevier science publishers b. These areas lie within the nanka formation in the anambra basin and are underlain by the tertiary bende ameki formation. This study adopts geographic information systems gis as a tool to identify and study gully erosion hazards in abia state. The objectives of the present study are to investigate and carry out water budget analysis of agulu lake areas and the underlying aquifers and relate these to the gully erosion problems. An assessment of the socioeconomic impacts effects of agulunanka gully erosion, anambra state, southeastern nigeria soil erosion is the systematic removal of soil including plant nutrients from the land surface by various agents of denudation.
Other catastrophic gullies occur at amucha, isuikwuato, ohafia, abriba and arochukwu in imo state, and in parts of uyo and calabar in cross river state. Gully erosion is best characterised as a bed instability that subsequently causes in bank instabilities. The aim of this study is to assess the adverse social and economic implications of gully erosion hazards in agulunanka communities of anambra state, southeastern nigeria. Soil erosion is the systematic removal of soil including plant nutrients from the land surface by various agents of denudation. An assessment of the socioeconomic impacts effects of agulunanka gully erosion, anambra state, southeastern nigeria ea9cbd uploaded by 15projects oct 26, 2016 soil erosion is the systematic removal of soil including plant nutrients from the. Mitigation measures against erosion gullying hazards in nigeria. Application of groyne as a sustainable solution to. To identify the adverse social effects that resulted from gully erosion in agulu nanka. Erosion control in the erosionravaged area of nanka adazi. Pdf 2014 scienceweb publishing evaluating the stability. Pdf evaluating the stability of gully walls in agulunanka. The agulu nanka o ko gully erosion complex is selected for this study due to its devastating nature that has attracted wide attention over the years.
Nwosu2 1 department of geological sciences, and 2 department of industrial microbiology, anambra state. Spatial database for erosion sites was created using. The availability of farm land for agricultural production and construction activities have, been greatly reduced due to soil erosion. Evaluating the stability of gully walls in agulunanka. Ephemeral and classic gully erosionworksheet forms of erosion by water include sheet and rill, ephemeral gully, classic gully and stream bank. The unconsolidated, loose, friable and uncemented properties of nanka formation facilitate the concentration of gully erosion sites on it more than other geologic formations fig. Hydrogeologieally, the agulu nanka gully complex comprises a. The agulunanka gully complex area forms a part of anambra river. The study areas are located in agulu, nanka and urualla gully erosion sites within longitude 7o00 to 7 o 15e and latitude 5 o 56 to 6 o 15n figure 1. The mechanisms, failure processes and the hydrogeological factors leading to the enlargement of nanka gully, one of the biggest landslide sites in nigeria, were investigated. Ushaped gully showing unconsolidated sediments and gully floor slope at oko gully site. Geotechnical investigation of soil around mbaukwu gully.
Hydrogeologieally, the agulunanka gully complex comprises a series of aquifers separated by aquitards. Seasonally, figures put active erosion sites in imo and anambra states to about 1. Assessment of treatment options soil is a resource best used insitu, not in transit. This paper addresses the gully erosion problems of the nanka agulu area of anambra state, nigeria. Findings are that the adverse social and economic effects of agulu nanka erosion on the residents in the erosion affected areas differ significantly from the social and economic situation in the unaffected areas and there is no significant relationship between the social and economic effects of gully erosion in agulu nanka areas. Pdf the effects of agulunanka erosion on the socioeconomic. Statistical analysis of variability in properties of soils in. Feb 05, 2015 civil and environmental research issn 22245790 paper issn 22250514 online vol. This study is set to apply poisson and negative binomial regression models to identify the major factors that contribute. Nwosu2 1 department of geological sciences, and 2 department of industrial. This paper addresses the gully erosion problems of the nankaagulu area of anambra state, nigeria. Active gully erosion sites across the country are put at 2000 sites jaiyebo, 2002. The nanka sands constitutes the agulunankaekwulobiaorlu escarpment significant in the hydrogeological and geohazards studies of the area. Gis analysis of drivers of erosion and gullying in.
Anambra is famous with its agulu nanka oko ekwulobia gullies. The aim of this study was to rehabilitate the gully erosion site and reduce longer term erosion vulnerability in agulu nanka community. This paper examines the spatial variability of soil properties and factors contributing to the general pattern of variability in agulu nanka oko gully complex, southeastern nigerian. There is no significant relationship between the social and the economic effects of gully erosion in agulunanka areas. Statistical analysis of variability in properties of soils. An assessment of the socioeconomic impacts effects of agulu nanka gully erosion, anambra state, southeastern nigeria. Evaluating the stability of gully walls in agulunanka oko.
To identify the adverse social effects that resulted from gully erosion in. Harmattan that runs through the months of october to march, and the rainy season that begins in march and ends in october. Emenike department of geological sciences, anambra state university of. Introduction gullies can be prevented by such measures as increasing the absorptive. The southward moving sahara desert air mass causes the dry season which is associated with extreme aridity, a dusty atmosphere, lowering of. Mitigation measures against erosiongullying hazards in nigeria. Nanka agulu axis is a major erosion hit area in the state, where gullies have taken. Analysis and assessment of agulunnaka erosion impact on. The effect of soil characteristics on gully development and distribution has made it desirable to determine the spatial variability of its physical and chemical properties. Modelling of gully erosion site data in southeastern.
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