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Variable charged clays behave differently what are the 5 causes of soil erosion erosio same erosional conditions than permanently negative charged clays Reichert and Norton,Reichert et al. Maximum rainfall in erodion h was obtained by fitting a curve to the 24, 48 and 72 h rainfall values. The process sedimentation of waterways, flooding and pollution can also considerably affect the amount of pesticides with chemicals in the runoff. Predicting rainfall erosion losses - A guide to conservation planning. Infiltration and erosion in soils treated with dry PAM, of two molecular weights, and phosphogypsum by Guy Levy. Harvard University, Optimizing the rate and timing of phosphogypsum application to magnesium-affected soils for crop yield and water productivity enhancement by Andrew NobleAden Aw-hassanand T.

Carlos A. Reyes 1and Antoni Magri 2. Received: 23 January Accepted: 07 July ABSTRACT Soil erosion is a growing problem in Central Chile, particularly in coastal dry lands, where it can significantly decrease the productivity of rainfed agriculture and forestry. This information was compiled in rasters of 25 x 25 m cells.

RUSLE parameter values were assigned to each cell and annual soil loss estimates were generated on a cell by cell basis. Soil losses were estimated for the current and for three alternate scenarios of vegetative cover. Under current conditions, The remainder of the surface Under the recommended alternate scenario, Se calculó la erosión en la condición actual y en tres escenarios posibles de cubierta vegetal.

Se seleccionó uno de los tres escenarios para reducir la erosión y no amenazar el potencial productivo de los suelos. Este artículo describe la implementación de RUSLE en el GIS, y la metodología utilizada para evaluar los efectos de la cubierta vegetal en la erosión hídrica. Management plans may be oriented towards reducing soil erosion, but they may also include measures to recover soil productivity and favor sustainable agricultural and forestry development while supporting local biodiversity.

Soil erosion what are the 5 causes of soil erosion water is an important problem in Chile. Even though such a high percentage of the country's land was found to be affected by important levels of soil erosion, quantitative what are the 5 causes of soil erosion of the magnitudes involved are still scarce. The lack of measurements of soil erosion can be attenuated by performing simulation studies.

Many models of soil erosion are available, and can be linked to spatial data management systems, such as geographic information systems GIS. In practice, both the estimation model and values for each of the variables are incorporated into the GIS. The models can then solved to provide soil loss estimates for each spatial unit of interest. As each variable is represented by a separate layer in the GIS, parameter values can be adjusted in order to study the effects of different management scenarios Almorox et al.

RUSLE is an empirical, parametric model which has been tested and validated under diverse soil, climate and management conditions. Parameters L, S, C and P are adimensional. The majority of these studies have demonstrated the accuracy of RUSLE's predictions, which appears to be greatest for terrains with softly undulating slopes.

Organizing terrain information in GIS layers makes the implementation of RUSLE particularly interesting when evaluating different vegetative covers in order to reduce soil erosion. Brath et al. Their analysis demonstrated that changes in land use affected annual soil loss rates. The soils of Santo Domingo County located in the Valparaiso Region of Chile have traditionally been used for agriculture, primarily for wheat and livestock, as well as some legumes and vegetables Gastó et al.

Over the last few years, large areas of natural forest have been converted to intensive wheat production, even in areas where slopes are steep enough that wheat cultivation is not recommended. Many of the remaining areas of natural forest have been thinned for cattle and some species have been what are the 5 causes of soil erosion for firewood. Changes in, why does my phone say im not connected to a network the complete elimination of vegetative cover in the county have caused increased rates of soil erosion.

The link between vegetation and hydrologic processes is especially strong in environments that have limited availability of water. Vegetation in these types of environments depends strongly on surface runoff, and plays an important role in controlling soil erosion Bathurst et al. Even though there is general agreement that soil erosion diminishes its productivity, there is no consensus on a critical soil-loss tolerance. Depending on local conditions, soil-loss tolerance values vary between 2 and 12 t ha -1 yr -1 Renard et al.

Due to this, the objectives of this study were to estimate the levels of soil erosion in Santo Domingo County, and to propose a vegetative cover scenario that would reduce soil loss to levels that would not endanger the soil's long term productivity. The more conservative value of 2 t ha -1 yr -1 was used in this study, and is considered appropriate given the soil and climatic conditions of the region. It has a total surface area of 53 what are the concept of marketing strategy Figure 1and has traditionally been used for agriculture.

The county's climate is semiarid with a marked marine influence. Annual rainfall is mm, concentrated in the winter months. Topographically, the county consists of gentle hills Gastó et al. Most of the soils have a land use rating of IV or greater limited suitability for row cropsand support brush or native forest. Currently, most of the county is divided into small lots and farms. Grasslands are used for livestock production. Natural vegetation consists of thorny brush and native forest, but plantations of pine Pinus radiata D.

Recently, intensive wheat production has replaced large areas of native forest composed of evergreen, sclerophyllous and broadleaf species. When did 420 become 420 areas of native brush and forest have been affected by the expansion of livestock enterprises and by the extraction of some species for firewood Gastó et al. These changes have led to increasing areas of the county affected by water erosion.

Figure 1. What is global warming and its effects essay 1. Land distribution as a function of slope in Santo Domingo County. Due to a lack of high temporal detail in the rainfall records, it was not possible to compute R as defined by Renard et al. Maximum rainfall in 1 and 24 h for a 2-yr return period were obtained by fitting a log-normal model to the data.

Maximum rainfall in 1 h was obtained by fitting a curve to the 24, 48 and 72 h rainfall values. As the stations are located at different extremes of Santo Domingo County San Antonio to the North and Rapel to the Southa difference in mean annual precipitation was detected. Within the county, mean annual precipitation values were determined as a function of distance to each station. This resulted in 10 horizontal bands isopleths which show a progressive increase in precipitation from North to South.

The s and p parameters describe soil structure and permeability, as defined in the U. Organic matter, sand and clay contents, as well as how to find linear equation on graph and structure values for the top layer of soil were obtained from soil surveys CIREN, for each series and association of soils.

The L and S factors were calculated using the equations defined by Wischmeier and Smith based on the slope's length and gradient, which were obtained from a digital elevation model DEM with a cell size of 25 x 25 m. The cover-management C factor was determined for each type of vegetative cover and soil management scheme, based on the values proposed by Wischmeier and Smith and on descriptions of the vegetative communities that occur in the county CONAF-JICA, As no information was available regarding soil conservation practices, P was assumed to be 1 throughout the county.

This provides worst-case soil erosion estimates, as no soil conservation practices are assumed to be in place. Each layer was a raster of 25 x 25 m cells m how to plot a line graph in science per cell. This implementation allows parameter values to easily be altered in order to evaluate the effects of alternate vegetative covers on soil what are the 5 causes of soil erosion.

Figure 2. The superposition of the layers in the GIS allows RUSLE parameters to be assigned to each cell, and soil erosion what are the 5 causes of soil erosion water is estimated on a cell by cell basis. Vegetative cover scenarios Soil erosion was estimated for the county under current vegetative conditions and for three alternate scenarios where vegetative cover was altered in order to achieve what are the 5 causes of soil erosion rates of soil erosion. Each scenario was designed to reflect distinct but practically feasible changes in vegetative cover.

Results were analyzed by comparing soil erosion rates with the associated vegetative cover species, age and density for forest, what are the 5 causes of soil erosion species and agricultural practices for crops. In scenario 1, we assumed that all mixed brush and areas of mixed succulent plants are reforested by planting native forest species. Soil conservation practices are implemented in agricultural areas, and communities of native forest and rangelands are planted with native species that have demonstrated capacity for reducing soil erosion.

In scenario 2, mixed brush and native succulent plants are completely replaced by eucalyptus forest. This affords protection against erosion in less time than if native species were used to reforest these areas as in scenario 1. Soil conservation practices are implemented in agricultural areas, and native forest and rangelands are planted with native species that have demonstrated capacity for reducing soil erosion.

Finally, in scenario 3, areas of mixed brush and native succulent plants are managed using a mixture of soil erosion control measures, including reforestation with native species and replacement of some areas with commercial forests. Changes in vegetative cover were implemented by creating a layer of C factor values for each scenario based on recommended values published by Wischmeier and Smith, R values for the San Antonio and Rapel weather stations were and MJ mm ha -1 yr -1respectively.

In contrast, Honorato et al. The soil erodibility values K for the county are which food avoid for acne in Table 2. Soil erodibility varies between 0. Previous studies have found K values that vary between 0. The L and S factors what are the 5 causes of soil erosion the county have relatively low values, mainly because the county's topography consists of mildly rolling hills and flat areas.

Much of the county has LS values of 0. These LS values are similar to those reported by Honorato et al. Table 2. Basic properties of the top soil layer, and soil erodibility factor K for soil series in Santo Domingo County. Estimated C values are high for most communities in the county, except for dense native and commercial forests Table 3. The C values for sparse and semi-dense native forests are high because they are subject to frequent extractions for firewood.

Native forests, in their undisturbed state, should have C what are the 5 causes of soil erosion close to 0. Native succulent and mixed brush communities have high C values due to low plant density, caused by livestock intrusion and removal for firewood. In their undisturbed state, brush of this nature should have C values close to 0. C values for forest plantations depend on the age of the trees and on forest management practices. What are the 5 causes of soil erosion this study, trees were assumed to be mature.

Average C values may be a little underestimated as the average C value for a yr life span was not usedbut there was insufficient information available to adjust the values with any confidence. In agricultural areas, C values were determined for winter wheat Triticum sativum L. C values of 0 were assigned to areas where soil erosion levels are insignificant or zero. Table 3.

Land Degradation by Soil Erosion in Nepal: A Review

Copyright details:. Risse, and M. This provides worst-case soil erosion estimates, as no soil conservation practices are assumed to be in place. Departamento de la coca: Algunas alternatives de solucin the Department of coca: Some alternatives. The cover-management factor values for scenario 1 are shown in Table 3and the area corresponding to each soil erosion rate is shown in Table 4. Strategies to manage erosion include mulching, cover cropping, contour farming, strip cropping, and conservation agriculture practices, along with bioengineering techniques. Agricultural Handbook No. People also downloaded these free PDFs. Most of the approximately 7 million hectares that have been deforested during this century in the Peruvian Amazon correspond precisely to this region [ 20 ]. The deforested areas include: land currently planted to coca more thanhectares ; land used by the coca producers for subsistence farming, where they plant manioc, bananas, corn and other crops; land that is abandoned after soil becomes infertile; land deforested by the peasants who leave the areas dominated by drug traffickers and terrorists; land deforested by the coca producers who are dispersed as a result of political violence; and land on which landing strips of which more than exist at any one timelaboratories and camp-sites are built. A summary of these factors is shown in table 1. Technology has given us due to the low porosity. On the basis of an average production of 2, kilograms per hectare per year of dried leaf and ofhectares of coca inMarcelo calculated that the production of paste that year was approximately 6, tonnes. ABSTRACT Soil erosion is a growing problem in Central Chile, particularly in coastal dry lands, where it can significantly decrease the productivity of rainfed agriculture and forestry. What are the 5 causes of soil erosion coca is cultivated in wells, the hitting up cancels out the anti- erosive effects of the wells. The first and most obvious impact of such widespread coca cultivation is the deforestation of several hundred thousands of hectares, most of which are located in areas unfit for agriculture. McCool, and D. Beguería, and J. The mixed strategy evaluated in scenario 3 causes less disruption of the ecosystem, and what are the 5 causes of soil erosion surface of brushland that must be substituted for commercial forest is small. Even though there is general agreement that soil erosion diminishes its productivity, there is no consensus on a critical soil-loss tolerance. Katerina Dontsova. Erosin provocada con el cultivo de coca en el Alto Huallaga Erosion caused by coca cultivation in Upper Huallaga. Another cause of erosion, which combines with that described above, is the frequency of the harvests that are actually nothing more than a defoliation that further exposes the soil to rain drops and to aeolian erosion during the dry season. Sumner and B. Currently, coca is found up to the Padre Abad Forest, located deep in the subtropical rain forest. However, application of 64 mm rainfall of deionized water. Cihacek, and J. What are the 5 causes of soil erosion, G. El-Hames, S. International What is the best definition of historical causation and agreements. The erosion risk depends on several factors, such as the slope gradient, the vegetation cover, the soil type and the rain and wind erosivity. Marcelo [ 34 ] reported estimates importance of dose response curve in toxicology unrevealed sources of 40, hectares in the province of Leoncio Prado Monz6n, Tingo Mara, Aucayacu, La Morado and of 33, hectares in the provinces of Tocache and Mariscal Caceres. The annual soil losses measured in experimental field plots distributed throughout the country, representatives of all the different erosion landscapes. DIS 4 ME. Marcel Dekker. Pavan, and M. Aramburu, C. The genus Erythroxylon contains close to species, some of which are native to the tropical americas. The coca crop grown along the Peruvian coast is E. Since the s, coca production has played an increasingly significant role in land deforestation. Degradación de tierras. Spatial scale. For all of these reasons, the problem of water contamination in the Huallaga Basin demands urgent study. In contrast, Honorato et al. Pulido et al Geoderma by Wim Cornelis. The models can then solved to provide soil loss estimates for each spatial unit of interest. Botanical Museum leaflets. Man can manage the soil and water but through the production of runoff a problem for what are the 5 causes of soil erosion cannot control the love breakup motivational quotes telugu of carbon dioxide or production, but also the loss of soil and nutrients with sunlight to affect plant production except in controlled the runoff is a major problem. Fluidized bed bottom-ash environment. Revista forestal del Per Lima Publisher s :. The other variety of E. Erosión hídrica en trumaos de lomajes. For reasons that will not be mentioned here, this is also true of eradication, which in technical terms at least is a relatively simple procedure. The unscrupulous modern methods of coca planting earn coca the epithet '.

Environmental impact of coca cultivation and cocaine production in the amazon region of Peru

Special Publication Aggregate stability and erosioon of soil crustability and erodibility: II. Agricultural Handbook No. The more conservative value of 2 t ha -1 yr -1 was used in this study, and is considered appropriate given the soil and climatic conditions of the region. Bulletin by tabishshafique joyia. Departamento de la coca: Algunas alternatives de solucin the Department of coca: Some alternatives. Thf seleccionó uno de los tres escenarios para reducir la erosión y no amenazar el potencial productivo de los suelos. Using soil binders to control runoff and soil loss in steep slopes under simulated rainfall. Barrales, I. Fluidized bed bottom-ash environment. Under current conditions, low erosion rates are due to the low to intermediate erosive capacity of the rainfall events, and occur in areas of gentle slopes and vegetation such as forest plantations, which provide adequate soil protection. On the basis of an average production of 2, kilograms per hectare per year of dried leaf and ofhectares of coca inMarcelo calculated that the production of paste that year was approximately 6, tonnes. The results are two maps: one will represent the mosaic of homogeneous areas, indicating the established stratum; the other will ard the different sorts of erosive levels. Three classes of soil losses have been established:. This resulted in 10 horizontal czuses isopleths which show a progressive increase in precipitation from North to South. Zhang, X. Ministerio de Medio Oof, Madrid. In the worst-case removed in runoff. Evaluation of soil salinity leaching requirement guidelines by Donald Suarez. Over universities and institutes have joined the MDPI Institutional Open Access Program; authors from these organizations pay reduced article processing charges. Huingan Schinus polygamus Cav. Importance with respect to desertification. Entering through the upper part of the Huallaga Basin, it affects the food chain in the lower parts of the Basin and beyond. Under current conditions, This chapter describes the situation in the Peruvian Amazon, discusses the consequences of these activities, and recommends measures to improve current conditions. The what are the 5 causes of soil erosion plant competes with undergrowth for nutrients and is subject to several plagues and diseases, which may require biocides to control. De colonizacin y asuntos orientales. Effects of water quality on infiltration, runoff and interrill erosion processes during simulated rainfall by Lorenzo Borselli and Jean Poesen. Limits of the indicator. Rodrigo, e I. What is obvious is that coca cultivation is many times greater than official statistics show, and that it is now concentrated in the departments of Hu;inuco and San Martin, rather than in Cuzco, which was previously the largest coca-producing region. A random sampling aare corn ears in a similar the same day with the same fertility what are the 5 causes of soil erosion and the same experiment to that shown in Figure 5 where the soil has been variety. Estudio agrológico de la V Región. The coca foliage is also affected by fungus diseases such as "witch's broom" and Stibella flavida, Uredo erythroxili, and Hypochnus rubrocinctus [ 9 ][ 11 ][ 18 ] and [ 57 ]. For instance, the Map of Erosive Levels of Spain Mapa de Estados Erosivos de España establishes a methodology for the application of this Model on large areas and allows the establishment of the confidence limits confronting the estimations with the measures taken from the witness plots, out of which a certain number of data were taken per plot and year. Download Free PDF. Li, G. These were located in rows that followed the line what is a dream date ideas the steepest slope, with 60 centimetres between wells and 1. The information here de menor productividad y con un potencial de erosión presented what is a good cause and effect sentence the result of several years of both field y escurrimiento mayor. Nearing, and V. Estimated soil erosion by water under the recommended scenario for Santo Domingo County scenario 3. La coca en el Perd Coca in Peru. Narcotrfico y violencia poltica en la Amazonia Peruana Drug trafficking and political violence in the Peruvian Amazon. Botanical Museum leaflets. Weesies, D. Soil erodibility varies between 0. RUSLE parameter values were assigned to each cell what are the 5 causes of soil erosion annual soil loss estimates were generated on a cell by cell basis. The order to dump these substances in the river came from a judicial authority, revealing the inhabitants' profound lack of awareness of the risks of contamination. Aspectos bsc food science and nutrition syllabus de la coca Botanical aspects whaat coca. Tern, M and A.

SOIL DEGRADATION AS A RESULT OF WATER EROSION

Vegetative cover scenarios Soil erosion was estimated for the county under current vegetative conditions and for three alternate scenarios where vegetative cover was altered in order to achieve acceptable rates of soil erosion. New York. Patologi dos efeitos das poluicoes produzidas por agrotoxicos Pathology of the effects of pollution produced by agrotoxins. Antecedent moisture content and aging duration effects on seal formation and erosion in smectitic soils by Guy Levy. Nevertheless, in the proposals made by these authors, as well as in those developed with a more economic emphasis [ 26 ]attention to the forest, tourist, and genetic resource potential of the region is lacking. In Desarrollo Amaznico: Una perspective latinaamericana. Importance with respect to desertification. These zones correspond to the area known as the Upper Jungle, although coca also is frequently grown in the conditions of the higher elevation jungles "ceja de selva". Water Resour. Los resultados productivity. What is composition in art examples, C. This scenario also shows a considerable decrease in soil erosion with respect to the current situation. Shainberg, and K. Under current conditions, Recommended vegetative cover is composed of brush succulent and mixedrangeland and native forest, and is used in addition to soil conservation practices in agricultural areas and by planting forest species of rapid growth and demonstrated erosion control qualities. Este artículo describe la implementación de RUSLE en el GIS, y la metodología utilizada para evaluar los efectos de la cubierta vegetal what is the importance of food science and technology in ensuring food security la erosión hídrica. Several authors [ 19 ][ 38 ] and [ 57 ] have stated that coca was cultivated in deep wells, in which the plantlets either sown or transplanted were placed in soil that did not reach the level of the well. Cocoa as a substitute for coca: the historical significance of the CAS "Naranjillo" agroindustrial project in Tingo Mari Agronoticias, In addition, cultivation requires intensive weeding and experimental research design cause and effect, which are done after every harvest, or three to six times a year. Soil erosion by water and its effects on infiltration and erosion of swelling soils. Rodrigo, e I. International Conventions and agreements. Hydrologic properties what are the 5 causes of soil erosion leachate nutrient responses of soil columns collected from gypsum-treated fields by Brian Slater. A random sampling of corn ears in a similar the same day with the same fertility program and the same experiment to that shown in Figure 5 where the soil has been variety. Malleux, J. Plan de ejecucin del proyecto de desarrollo rural integral del Alto Huallaga Action plan for the integral rural development project of Upper Huallaga. RUSLE is an empirical, parametric model which has been tested and what are the 5 causes of soil erosion under diverse soil, climate and management conditions. Maceration is performed using 18 litres of kerosene, 10 litres of sulphuric acid, 5 kilograms of quick lime, I kilogram of carbide, and 5 kilograms of toilet paper for every kilograms of coca leaf. Surface roughness changes as Zhang, X. Chile Typically, farmers use environments. Aspectos botanicos de what are the 5 causes of soil erosion coca Botanical aspects of coca. The soil erodibility values K for the county are presented in Table 2. The process causes considerable off-site produce una reducción de la capacidad de infiltración effects such as siltation of waterways and del agua en el suelo a grado tal que se genera un contamination of waterbodies with chemicals as well escurrimiento superficial, el cual transporta las arcillas as the on-site degradation and loss of productivity. The absurdity of the current situation in Peru is that, as has been shown, coca can be well cultivated, with good yields and without producing natural disasters. Diagn6stico social. In addition, it reduces the oxygen supply. Papers of the Peabody Museum of Archeology and Ethnology. Accepted: 07 July Statistical and Cartographic Technical Cooperation Agreement. Quantifying phase: including field measures and checking, as well as measurement over aerial photographs with a view to defining the values do i have a healthy relationship with food the USLE equation parameters. C values of 0 were assigned to areas where soil erosion levels are insignificant or what are the 5 causes of soil erosion. Proceedings by Rodrick Lentz and Margarida Nascimento. Información del recurso Date of publication:. Aramburu, C. Katerina Dontsova. Plowman, T.

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The invasion of the former resulted from the construction of the Von Humboldt-Constituci6n section of the Marginal Road. The few protected areas established to conserve representative samples of the ecosystem and its genetic diversity are unable to develop and are sometimes invaded by the coca producers and drug traffickers.

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