Helping north coast landholders reduce soil erosion. In turn, unsustainable land use is driving land degradation. Unlike previous studies that dealt with soil erosion as a static process, here we shed light on the impacts of 21st century global land use change on soil erosion. Pollution of water resources from the contamination of. It refers to a special form of soil degradation in arid, semiarid and dry.
Indirect drivers of land degradation in grenada the indirect drivers of land degradation in grenada are the driving forces of the direct causes of land degradation. Land and soil are important components of abu dhabi emirate desert ecosystems and of the wider environment in which all plants and animals live. The human dimension of land degradation and forest degradation 414. Soil erosion is the displacement of the upper layer of soil, it is one form of soil degradation. On land degradation free download as powerpoint presentation.
Soil erosion is a common term that is often confused with soil degradation as a whole, but in fact refers only to absolute soil losses in terms of topsoil and nutrients. The world is losing 10 ha of arable land each minute5 ha to soil erosion, 3 ha from salinity, and 2 ha by other degradation processes. Soil degradation is a critical and growing global problem, with implications for a number of key policy areas, including food security, climate change, flood risk management, drought tolerance, drinking water quality, agricultural resilience in the face of new crop diseases, biodiversity and future genetic resources. Soil erosion is a natural process in mountainous areas, but is often made much worse by poor management practices. With a high rate of population growth, subsistencebased rural economy, and increasingly intense rainfall events in the monsoon season, nepal is prone to several forms of land degradation, such as floods, landslides, and soil erosion. Compaction compaction is where soil particles pack together increasing soil density and reducing pore space. Soil, degradation, salinization, land quality, land rehabilitation, food security introduction land degradation will remain an important global issue for the 21 st centur y because of its. Routing runoff and soil particles in a distributed model with gis. But, in the field, further variables are used as indicators of the occurrence of soil degradation. The result is a loss of land productivity with impacts on livelihoods and the. This site is like a library, use search box in the widget to get ebook that you want. Click download or read online button to get land degradation book now.
Desertification is accentuated by land misuse and soil mismanagement. Rill erosion is common in bare agricultural land, particularly overgrazed land, and in freshly cultivated soil where the soil structure has been loosened. On land degradation environmental degradation erosion. Pdf soil degradation is one of the major global threats. Field research stations report soil losses 35 to 246 tons hayr, and farmers report declining productivity of their fields. Pdf on apr 9, 2014, velibor spalevic and others published land degradation, land use and soil erosion. Land degradation here mainly refers to the loss of lifesupporting land resource through soil erosion, desertification, salinization, acidification, etc. This natural process is caused by the dynamic activity of erosive agents, that is, water, ice glaciers, snow, air wind, plants, animals, and humans. With a high rate of population growth, subsistencebased rural economy, and increasingly intense rainfall events in the monsoon season, nepal is prone to several forms of land degradation, such as.
It is defined as any change or disturbance to the environment perceived to be deleterious or undesirable. Soil on construction sites is also degraded by compaction. Pdf land degradation, particularly soil erosion, is currently a major challenge for nepal. It encompasses physical soil erosion, chemical salinity and alkalinity, pollution and biological deterioration pollution and. Destruction of natural vegetation cover is a major factor responsible for erosion of soils by water and wind. Soil loss from conventionally tilled land exceeds the rate of soil formation by 2 orders of magnitude medium confidence. Careless agricultural practices, pollution and deforestation cause lots of soil degradation in the world. In a typical scenario, large equipment is used to remove topsoil from a construction site. Chapter 2 types of land degradation food and agriculture. Eastern africa including ethiopia has experienced moderate to severe land degradation problems as shown in. Assessment of soil erosion by rusle model using remote. The older agricultural areas of the northeast have long been particularly affected, but the highest soil erosion rates are currently being observed in the western parts of the high lands. Wind erosion is a common cause of land degradation in the arid and semi arid grazing lands of inland queensland. Land degradation explores the substantial decrease in an areas biological productivity or usefulness to humans due to human activities.
Land degradation is the major consequences of direct interference of human activities in the natural phenomenon. While this is a dynamic process that is occurring naturally all the time on a small scale, the results of largescale soil movement can be devastating to soil health and productivity. It is viewed as any change or disturbance to the land perceived to be deleterious or undesirable. Soil degradation is a serious global environmental problem and may be exacerbated by climate change. Watershed degradation is the loss of value over time, including the productive potential of land and water, accompanied by marked changes in the hydrological behaviour of a river system resulting in inferior quality, quantity and timing of waterflow the protection, improvement and rehabilitation of mountain andor upland watersheds are of critical importance in the achievement of.
Land degradation is a process in which the value of the biophysical environment is affected by a combination of humaninduced processes acting upon the land. Leaving more land alone, despite the challenges of a growing population, would really help. By this, the land area affected by soil degradation due to erosion is estimated at 1100 mha by water erosion and 550 mha by wind erosion. Soil is a complex body and forms the thin outer layer of the earth. Principal processes of land degradation include erosion by water and wind, chemical degradation comprising acidification, salinization, leaching etc. According to a united nationsbacked study, a third of the planets land is severely degraded and fertile soil is being lost at the rate of 24 billion tonnes a year. Accelerated erosion by wind and water in drylands is one of many causes of desertification. Environmental degradation is the deterioration of the environment through depletion of resources such as air, water and soil.
United nations convention to combat desertification. Soil science institute of athensnational agricultural. The second edition of johnson and lewiss wellreceived text thoroughly. Significant wind erosion occurs when strong winds blow over lighttextured soils that have been heavily grazed during periods of drought. By giving the current land condition, the soil conservation status fits as an indicator of the land degradation status as defined in the ldn framework cowie et al. Land degradation soil degradation is the decline in soil quality caused by its improper use, usually for agricultural, pastoral, industrial or urban purposes. Loss of vegetative cover has made land more susceptible to erosion. This study takes the degradation of soil resources as its focus. Land degradation is, usually, the result of complex interrelationships between biophysical and socioeconomic issues which affect many people and their land, specially in the tropics and developing countries.
Ethiopia is known for its historic agriculture, but also for the associated, widespread, and ongoing land degradation. Experts suggest rotating pastured land used by the meat and dairy industries so less is being used at once. Soil erosion is one of the factors responsible for lad degradation. Photograph of a compacted zone of soil immediately below the plough layer in a cropping soil. World overview of conservation approaches and technologies. Trafficking by animals as well as by vehicles and cultivation are the primary causes of this form of soil degradation. Land degradation download ebook pdf, epub, tuebl, mobi. The acceleration of soil erosion is generally a symptom of. Future approaches should continue to address these issues while creating a better information flow on the true costs of land degradation and in addition approaches. Several types of soil degradation exist and are a threat to natural forests and planted crops. While losses are uneven this represents a loss of 4 mm of soil a year, twenty or more times.
Estimation of soil erosion risk using the universal soil loss. Land degradation indicators and management options in. Soil erosion and the effects of soil erosion on crop productivity have become emotional issues and have attracted the attention of agriculturists, environmentalists, and the public in general. Land degradation is the temporary or permanent lowering of the productive capacity of land unep, 1992b. Significant wind erosion occurs when strong winds blow over lighttextured soils that have been heavily grazed during periods of. An assessment of the global impact of 21st century land. Soil degradation associated with poor soil fertility management practices is a major factor underlying poor agricultural productivity in subsaharan africa. Soil erosion is the movement of soil, via wind or water, from its original position in the landscape. Water erodes top soil to an extent of around 12,000 million tonnes mt per annum. Soil erosion leads to losses in soil and crop productivity, pollution of land and water resources, and a loss of farm income. For example, the land productivity classes include class i, extremely high.
Taking land out of production would allow soil carbon to rebuild and become stable. A conceptual model of natural land degradation based on regressive pedogenesis in semiarid tropical. Land degradation has long been recognized as a major problem in rwanda, especially impacting the southwest of the country, but important everywhere. Soil degradation is any type of problem that removes soil in an area or makes highquality soil become poor. Here, we modify a physicallybased wind erosion sediment transport model to better represent the vegetation cover using land surface aerodynamic roughness. It can be prevented by formation of ridge and furrow during irrigation which lessens run off. In spite of heavy investments in research and development, the global rates of accelerated erosion are now presumbly higher than ever before. Land degradation is the temporary or permanent lowering of the productive. However, degradation has led to most arable soils having already lost 40 to 60% of their organic carbon. Soil degradation is, in itself, an indicator of land degradation. Soil erosion occurs when soil is removed through the action of wind and water at a greater rate than it is formed soil the soil covering the surface of the earth has taken millions of years to form and we must learn to respect it. Uneps project global assessment of soil degradation glasod was. Introduction soil erosion represents one of the most serious land degradation problems 1.
Sustainable land use can help to reduce the impacts of agriculture and. Erosion rate soil erosion soil loss sediment yield land degradation these keywords were added by machine and not by the authors. Water erosion aspects of land degradation neutrality to. Soil degradation results when the soil is left exposed to the forces of erosion. In accordance with these agents, erosion is sometimes divided into water erosion, glacial. Land degradation indicators and management options. Soil loss from conventionally tilled land exceeds the rate of soil formation by. Causes and impacts of land degradation and desertification. Loss of natural fertility of soil because of loss of nutrients. It is directly or indirectly developed from the mineral constituents of the rocks.
Sustainable land use can help to reduce the impacts of agriculture and livestock, preventing soil degradation and erosion and the loss of valuable land to desertification. Download land degradation or read online books in pdf, epub, tuebl, and mobi format. The decline in quantity and quality of soil it includes erosion by wind and water biological degradation loss of humus physical degradation loss of structure, permeability, compaction chemical degradation reduced fertility, salinisation, changing ph, toxicity if degradation is so severe that land becomes unusable it is termed desertification. An introduction towards one of the massive soil issues. The world is losing 10 ha of arable land each minute5 ha to soil erosion, 3 ha from salinity, and 2 ha by. This includes soil erosion by water and wind, deterioration in soil physical. For example, planting crops at a location with heavy rainfall and steep slopes would create scientific and environmental concern regarding the risk of soil erosion by water, yet farmers could view. Loss of topsoil by wind erosion et, defined as a uniform displacement of the. Degradation of the soil is caused by natural processes as well as by human activities. Deforestation accounts for the major land degradation problem as it results in severe soil erosion, flood, and loss of fertile soil. Causes and features of watershed degradation related to.
Soil physical damage is an increasingly serious problem for agriculture. Soil erosion and degradation on mediterranean type ecosystems. Agents of erosion like wind and water have left vast tracts of land barren. This erosion is the dominant form of soil degradation troeh et al. This is indeed the most visible effect of soil degradation, but does not cover all of its aspects. Grenada land degradation neutrality national report.
Research findings revealed that the rate of soil erosion on cultivated lands across the country was 42 mgha. Different processes of land degradation also confound the available statistics on soil and or land degradation. Rill erosion can be reduced by reducing the volume and speed of surface water with grassed. Efficiency of four different seeded plants and native vegetation as cover crops in the control of soil and carbon losses by water erosion in olive orchards. Soil is subject to a series of induced degradation processes, which humannamely are displacement of soil material, and internal soil deterioration dwivedi, 2002.
Technical report on soil degradation european commission. Introduction watershed is not simply the hydrological unit but also a sociopoliticalecological entity which plays decisive. The present rate of land degradation is estimated at 5 to 7 million hectares per year, suggesting that 0. This process is experimental and the keywords may be updated as the learning algorithm improves. It thus covers the various forms of soil degradation, adverse human impacts on water resources, deforestation, and lowering of the productive capacity of rangelands.
Land degradation as the land use section earlier in this chapter shows, demands on the land for economic development and pressures from a burgeoning population are leading to unprecedented land use change. Deforestation causes fast degradation when the soil is steep sloppy or easily erodible. Land degradation, soil erosion and soil conservation pmf ias. The term land degradation involves both soil and vegetation degradation. May 01, 2019 land degradation soil degradation is the decline in soil quality caused by its improper use, usually for agricultural, pastoral, industrial or urban purposes. The rills can usually be removed with farm machinery. About 65% of the agricultural land is degraded, mainly due to low nutrient application, soil erosion and soil acidification. And degraded lands are also often less able to hold onto water, which can worsen flooding. The soil integrates a variety of important processes involving vegetation growth, overland flow of water, infiltration, land use and land management. Soil erosion in india has a major effect on the agricultural sector, siltation of reservoirs, degradation of soils, etc. Watershed, evaluation, soil erosion, land degradation, soil and water conserva tion, community based watershed management subject areas. T value tolerable erosion equilibrium between soil gains and losses. The health of soil is a primary concern to farmers and the global community whose livelihoods depend on well managed agriculture that starts with the dirt beneath our feet. The human dimension of land degradation and forest degradation.
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