Protection of the head of the gully can be done by. Through water erosion, approximately 400 thousand gully erosion formations were formed, covering over 500 thousand hectares according to g. Classic gully a channel or miniature valley cut by concentrated runoff into the earth, but. Programs to control erosion in queensland began in the 1950s and have been very successful. Evaluating factors responsible for gully development at. This paper examines gully erosion and its damage, and existing gully control practices in two rural communities, in the northwestern highlands of ethiopia. The gully contains a watercourse which discharges to the te. The criteria used for selecting gully control measures in table 2 are to be used for continuous gullies, gully networks, or multiplegully systems located in deteriorated mountain watersheds. The purpose of gully control is not so much erosion control as an attempt to limit the effects of erosion which is taking place upstream from the gully. Gullies start when fast flowing runoff hits a nick point such as a rabbit burrow, root hole, stockvehicle track, or bare soil.
Even if the proposed treatment cost for the gully is high, it is usually economical to protect the soil from further damage. Flumes flumes are artificial channels that control the flow of water down a slope and release it into an area where its impact is reduced. Erosion preceded by the destruction of the crumb structure due to the impact of falling raindrop on the surface of soil is termed as splash erosion. Data were gathered from measurement of the dimensions of 26 selected gullies in a farmerparticipatory approach. We also appreciate the work of the following national advisory. Gully erosion is the removal of soil along drainage lines by surface water runoff. Disturbing dispersive soils may reactivate the gully and cause more erosion. However, with changes to landuse, grazing, cane production and mining, there has been a significant increase in erosion across the landscape alongside the great barrier reef. The gully edges are pushed into the centre, which is compacted. Several mechanical methods are used to control and prevent erosion. Many conservation practices can be implemented to control wind erosion.
Therefore, in erosion control or gully control, emphasis should be given to. Gross erosion includes sheet, rill, gully and channel erosion, and is the first step in the process of. Although soil erosion is a natural process, it is often accelerated by human activities, for example by the clearing of vegetation, soil tillage or overgrazing. For severe erosion, it is a good idea to get technical advice to find the best solution for your situation. Mechanical control of erosion te ara encyclopedia of new. This sediment would be lost further downslope without this wattle. Without effective erosion controls, we dont really see how storms carry soil away. If the cause of the erosion cannot be reversed, then it may not be appropriate to restore the gully back to its preerosion condition.
It also reduces the speed of water flowing over the land. Conservation practices are designed to either reduce the wind force at the soil surface or. The warke watershed a project paper presented to the faculty of graduate school of cornell university in partial fulfillment of the requirement for the degree master of professional studies mps by birara chekol tarekegn january 2012. The first step of gully erosion control is to fence around gullies. Gully erosion erosion soil and water farm management. Stopping a gully from continuing to erode providing a place for water to move from your field and down into a stream or ditch what is a grade stabilization structure. The department of planning, industry and environment is the custodian of several datasets that show the location and relative severity of gully erosion, which can be viewed on the department data portal. Gully and stream bank erosion are naturally occurring processes. Therefore, readers of this guideline are advised to use the guideline as a learning. In this article we will discuss about how to control gully erosion. Watersheds deteriorate because of misuse of the land man made changes, short intensive rainstorms.
It also serves as a reference material to cascade down similar trainings to development agents and the land users at large. A better understanding of these aspects would allow one to better predict the impact of environmental change, gully prevention and control measures on gully erosion and gully infilling rates at. The lands position, soil type and slope determine how vulnerable it will be to. Do you have a problem with a gully or washout in your field. A free powerpoint ppt presentation displayed as a flash slide show on id. This natural process is caused by the dynamic activity of erosive agents, that is, water, ice glaciers, snow, air wind, plants, animals, and humans. Poor farming practices as well as the trend toward agricultural intensification have. This method was used successfully in the early 1960s at wither hills near blenheim. In pakistan, 75% of the country is affected by water and wind erosion and gully erosion affects 36% of the agricultural area of the country according to g.
Soil erosion can be avoided by using land within its capability. A study of early gullycontrol structures in the colorado. Heede, research forester introduction the control of gullies is an important step in watershed rehabilitation. Gully head treatment is low cost, effective in stopping gully advancement and can be managed by the financial and technical capacities of the local communities. Descriptive statistics and regression were used for data analysis. 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. Surface cover is a major factor to control erosion because it reduces the impact of raindrops falling on bare soils and wind removing soil particles. Ppt gully control measures powerpoint presentation. Gully erosion is more difficult and expensive to control than sheet and rill erosion. Gully control proposals can be appraised by using the costbenefit ratio method, present net value or internal rate of return method. Beginning gully reclamation at an early stage is important.
The tons of soil loss can then be determined by multiplying the volume removed by the unit weight of the soil. Grassed waterways gully erosion can often be controlled with a grassed waterway. Heede, research forester introduction the control of gullies is. The contour of the land is then shaped to spread runoff. This final detailed erosion and sediment control plan can also be provided to the whangarei district council prior to each earthworks season. Erosion risk is significantly reduced when there is more than 30% soil cover. It is the fairly uniform removal of soil in thin layers from the land surface, often scarcely perceptible, especially when caused by wind.
Gully erosion problems in selected areas of edo state. Sieve structures to control gully erosion on the borana. The principles of gully erosion control for reducing gully sediment yield wilkinson et al. Therefore, minimizing surface runoff is essential in gully control. Gully erosion results not only from surface flow but also often from subsurface flow. Slope and topography steeper slopes cause the flow velocity of. Though the region was agriculturally developed relatively recently, it went through high intensity cultivation and fast succession processes within shorttime scales. Preventing and managing erosion environment, land and. Although tillage removes the visible erosion, tillage moves soil into the voided area and loosens soil material for the next rainfall event. The following measures control gullies and other severe erosion problems. Gullies are the landform that are created by running water eroding.
I hope we can do something about this and help the people in the community. The rate of gully erosion depends primarily on the runoff producing characteristics of the watershed, the watershed area, soil characteristics, sizeshape and slope of gully etc. If untreated, the ephemeral gully may develop into a classic. This document provides a specification of the gully erosion control activities that can be undertaken. This manual will assist counties, townships and local units of government by providing guidelines and methods for effective erosion control practices on low volume roads. Introduction gully erosion is defined as the erosion process. The salinity of a soil can affect the amount of groundcover present, limiting the ability for growth and exposing bare areas to erosion.
Costeffectiveness is an important consideration given the extent of gully erosion to be treated in priority areas. The devastating gully erosion in auchi, edo state, nigeria. Estimating soil loss from gully erosion ephemeral or classic definitions ephemeral gully a shallow channel cut by concentrated runoff where soil loosened by mechanical operations is removed, generally between tillage operations. A study of early gullycontrol structures in the colorado front range by burchard h. Ppt gully control measures powerpoint presentation free. In general, this type of gully can be crossed with farm equipment and obliterated with tillage. It is also more spectacular than the other forms of erosion. Local agencies are required to develop erosion control plans. Types of erosion environment, land and water queensland. Infilling can be used where tunnel gully erosion has occurred. Assessment of gully erosion and practices for its control. An ephemeral gully typically erodes to the tilled depth.
The region is the grain production and ecological security base of china where the fertile and productive mollisols are distributed. To check whether the erosion is active, look at the gully head, walls and floor. Gully erosion occurs when running water erodes soil to form channels deeper than 30cm. Classic gully calculating gully erosion the soil loss from concentrated flow, gullies, and other similar types of erosion will be determined by calculating the volume of soil removed from the eroded area. Check whether the erosion is active gully erosion can look dramatic, but if the gully has stabilised it may be better to leave it alone. Only when the bed instabilities are under control can stabilisation of the gully head and banks occur. Subjective observations will continue to be used to satisfy quality criteria in lieu of scientifically defensib le, quantitative methods.
If water flows around wattle and creates rill or feeds gully erosion, fill and compact cuts, extend with additional wattle, rock mulch, etc with slight uphill grade. Once started, gullies will continue to move by headward erosion or by slumping of the side walls unless steps are taken to stabilise the disturbance. Nonscientific methods for accounting for and treating ephemeral gully erosion will. If the cause of the erosion cannot be reversed, then it may not be appropriate to restore the gully back to its pre erosion condition. How to stop gullies on eroded slopes howtopedia english. Effects of erosion control practices on nutrient loss george f. The best way to prevent gully erosion is to maintain good ground cover. Planning gully control can best be attained through a plan that takes into ac count the treatment of the watershed draining into the gully, as well as treatment of the gully itself. Soil erosion is a major environmental problem confronting land and water resources in south africa. Preventing and managing erosion environment, land and water. Gully toolbox a technical guide for the reef trust gully. Even if the proposed treatment cost for the gully is high, it is usually economical to protect the. The energy of the water scours away the soil, undermining the vegetation.
Contrary to sheet and rill erosion, the damage done to land by gully erosion is permanent. Gully erosion is caused when runoff concentrates and flows at a velocity sufficient to detach and transport soil particles. 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. Permanent gully control structures are constructed with the help of permanent materials such as cement, masonry, reinforce, concrete or earth. Repair work done in the early stages of newly formed gullies is easier and more economical than letting the. Addressing gully and stream bank erosion reducing sediment.
May 05, 2015 the devastating gully erosion in auchi, edo state, nigeria. Now that we understand how the wind moves soil and the serious consequences of unchecked wind erosion, lets discuss erosion control. As a result of historical landuse change, there have been. A study of early gully control structures in the colorado front range by burchard h. In upstream watersheds with very steep slopes, the gradient of the main gully channel can easily reach 100 percent or even 125 percent. Soil erosion is the displacement of the upper layer of soil, it is one form of soil degradation.
Soil erosion in south africa its nature and distribution. A waterfall may form, with runoff picking up energy as it plunges over the gully head. It has been common practice to implant concrete or rock barriers into erosion gullies in the hope that a solid barrier will counteract erosive activity and capture sediment. Gully erosion is the destructive and dramatic form of land degradation in northeast china. Understanding the cause of the gully erosion can help in identifying the best treatment option. Gully erosion, subsurface flow, saturation excess, infiltration excess, gully expansion, piezometer, treated area, untreated area, and soil loss. Splash back at the base of the gully head erodes the subsoil and the gully eats its way up the slope bruce, 2006. The rock barriers take the form of check dams made from a wall of rocks, or of gabions created by filling a strong wire cage with rocks. Natural resource management gully control measures richa rai 39 introduction what is gully. This has seen an increase in sediment and nutrient runoff into the reef. Sustainability free fulltext gully erosion control.
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