Cause And Effects Of Soil Erosion

Cause And Effects Of Soil Erosion The Latin word erodere,meaning to gnaw away is the origin of the word erosion (Roose, 1996). Soil Erosion is the physical removal of topsoil by various agents, including falling raindrops, water flowing over the soil profile and gravitational pull (Lal 1990). The Soil Science Society of America defines erosion as the wearing away of the land surface by running water, wind, ice or other geological agents, including such processes as gravitational creep (SCSA, 1982). Physical erosion involves the detachment and transportation of insoluble soil particles (sand, silt and organic matter). Removal of soluble material as dissolved substances is called chemical erosion and this maybe caused by surface runoff or subsurface flow where the water moves from one layer to another within the soil profile (Lal 1990). According to ASCE, 1975, the physical processes in soil erosion include detachment of soil particles, their transportation and subsequent deposition of soil sediments downslope by raindrop impact and runoff over the soil surface. Rainfall is the most important detaching agent (Morgan and Davidson 1986; Lal, 1990) followed by overland flow in entraining soil particles (Lal 1990). The process of soil erosion occurs in three main steps, detachment of soil particles, transportation and deposition of soil particles downslope by raindrop impact and runoff over the soil surface (ASCE 1975; Morgan and Davidson, 1986, Lal 1990) followed by overland flow in entraining soil particles (Lal, 1990). Soil erosion reduces soil productivity by physical loss of topsoil, reduction in rooting depth and loss of water. In contrast soil, soil depletion means loss or decline of soil fertility due to crop removal or removal of nutrients by eluviations from water passing through the soil profile (Lal, 1990). Sedimentation however, causes off site effects like degradation of basins, accumulation of silts in water reservoirs and burial of low-lying productive areas and other problems (Lal, 1990). Sediments is the main cause of pollution and eutrophication (Lal, 1990). According to Lal 1990, soil degradation may be caused by accelerated soil erosion, depletion through intensive land use , deterioration in soil structure, changes in soil pH, leaching, salt accumulation, build up of toxic elelments such as aluminum or zinc, excessive inundation leading to reduced soil conditions and poor aeration. Soil Erosion is the most serious and least reversible form of land degradation (Lal, 1977; El-Swaify, Dangler and Amstrong, 1982). Soil erosion and soil loss , according to Lal (1990) have adverse effects on agriculture because they deplete the soils productivity and diminish the resourse base. 2.2 Soil Erosion Process Geologic erosion can be caused by a number of natural agents including rainfall, flowing water and ice, wind and the the mass movement of soil bodies under the action of gravity which cause the loosened or dissolved earthy and rock materials to be removed from a place and eventually deposited to a new location (Lal,1990; Morgan and Davidson, 1986). The Soil Science Society of America (SCSA, 1982) described geologic erosion as the normal or natural erosion caused by geologic processes acting over long periods and resulting in the wearing away of mountains, the building up of flood plains, coastal plains. Etc. The slow and constructive natural soil erosion process has been significantly accelerated by human activities of poor farming practices, overgrazing, ground clearing for construction, logging and mining (Lo, 1990). Accelerated erosion not only affects the soil but also the environment and is the primary cause of soil degradation (Lal, 1990). Agriculture has been identified as th e primary cause of accelerated soil erosion (Pimentel, 1976). 2.3 Soil Characteristics in the Tropics Extremes of climate and wide variety of parent materials cause great contrast of soil properties in the tropics from soils in other temperate regions. In the tropics soils are highly variable and diverse like the vegetation (Sanchez and Buoi, 1975; Van Wambeke, 1992). The main soil types are alfisols, oxisols, ultisols and inceptisols (El-Swaify, 1990). Tropical soils low in weatherable minerals and basic cations (sodium, calcium, magnesium, and potassium) resulted from continuous weathering of parent materials (Lo, 1990). The ability of these soils to keep plant nutrients is largely dependent on the humus content found in plant biomass and the organic matter (Rose,1993). The inactivity of soil mineral constituents (kaolin and sesquioxides) in these soils, causes deficiency in crop nutrients, lowers the capacity to retain basic cations, limits active relationship with organic matter and excessively immobilizes phosphates and related anions, a condition which are highly toxic to plant roots (Lo, 1990). Crop production in tropical soils are constrained by primarily aluminum- derived soil acidity and infertility but generally their physical properties are favourable (El-Swaify, 1990). Tropic soils have moderate to high permeability under natural conditions, but susceptible to slaking and development of impermeable crust upon action of raindrops and as a result runoff increases with continuous cultivation (Lal, 1982). This crusting cause insignificant reduction of filtration rate, increasing water runoff which leads to acceleration of soil erosion (Falayl and Lal, 1979). It is important to note however that heavy and intense rains cause severe erosion in the tropics (Morgan, 1974; Wilkinson 1975; Amezquita and Forsythe, 1975; Lal 1976; Aina, Lal and Taylor, 1977; Bois, 1978; Sheng 1982). 2.4 Soil Erosion on Steep Slope According to Lal 1990, Steeplands refer to lands with a slope gradient greater than 20%. It is important to note however that flat undulating lands have a great potential for crop production and agricultural development. Due to the possibility of soil erosion and the problem of mechanization, the steep areas are considered marginal for agriculture production (Lal, 1990). The difficult topography in steepland agriculture restricts mechanizations of operations thus, reducing all agricultural activities (land preparation, cultivation and harvesting), limiting the farmer in scale and efficiency. Inputs such as fertilizer and pesticides have to be carried manually by the farmer. As a resulted they are used scarcely. Observably any increase in the use of these agricultural inputs will result in decline in he farmers profits from the generally lower agricultural field (Benvenuti, 1988). For all these reasons steepland farmers tend to concentrate in high value crop production of limited scale (Ahmad, 1987; Ahmad 1990). It is important to note however that farmers prefer steepslopes due to cultural hand cultivation, planting and harvesting can be done in an upright fashion (Williams and Walter, 1988). Futher more subsistence farmers are found on steep slopes because of more favourable environmental conditions such as lower temperatures, reduced diseases and h igher reliability of rainfall. (Hurni, 1988). In the tropics, removal of forest vegetation causes excessive leaching and accelerated soil nutrient loss. Being highly weathered soil types , their contained minerals generally have poor ability to retain sorbed nutrients against leaching. Clay soils with high residualmiron contents are considered superior in resistance to runoff caused soil erosion; thus, soils emanated from basic igneous rocks and red soils developed from calcareous rocks are strongly aggregated due to the cementing property of iron oxides, hence, soil erosion is expected to be less than for most other soils. Also soils developed from fragmentary volcanic materials with andic properties are resistant to soil erosion (Sheng, 1986; Ahmad, 1987; Ahmad, 1990; Lal, 1990). Soils formed from shales, schists, phyillites and sandstones are considered highly erodible. Soils produced from these rocks are high in both sand or silt fraction, and clay minerals and iron oxides are generally insufficient as cementing agents for a stable-structured soil. These parent materials are generally rich in muscovite occurring in all soil particle-size fractions. Micah-rich soils are weak-structured, and thus raindrops can easily dislodged the weak aggregates, while the clay fraction dispersed in water. The resulting mica flakes settling on their flat axes in the water film on the soil surface causes soil crusting. The formation of soil crusts further restricts water entry into the soil (Ahmad and Robin, 1971; Sumner, 1995), resulting to disposal of a much greater volume of runoff water, a condition which leads to further disintegration of soil aggregates and transport of colloidal soil material (Ahmad, 1987; Ahmad 1990). Soil crust restricts gaseous exchange leading to anaerobic soil conditions, denitrification, toxic effects due to ethylene production, and mechanical impedance to seedling emergence (Ahmad 1987; Ahmad, 1990). Steep slope cultivation can cause certain instability in the ecological system with both onsite and offsite detrimental impacts (El-Swaify, Garnier and Lo, 1987). Soil, climate, land use and farming systems affect the extent and the degree of severity of soil erosion. However, regardless of soil and climatic conditions, intensively used steeplands in densely populated regions experience severe soil erosion problem. Land use influences the degree of severity of soil erosion on steeplands. Uncontrollable grazing or over grazing, exensive and abusive cultivation, diversified cropping are responsible for severe soil erosion in unprotected arable lands (Roose, 1988; Liao et al 1988). Ahmad (1987;1990) reportd soil loss of approximately 120 t0 180 tonnes per hectare in Tobago Trinidad. In Australia, annual soil loss of 200 t/ha to 328 t/ha has ben reported from sloping sugar cane plantations in central and north Queensland (Sallaway, 1979; Mathews and Makepeace 1981). There are two types of soil erosion associated with the Caribbean region, land slipping and gullying. Land slipping is a manifestation of mass movement associated with steepland agriculture and the severity being strongly influenced by the parent materials. Land clearing (example deforestation) and crop production can influence land slipping particularly in the early portion of the wet season when the cleared soil wets faster due to saturation of the soil above rock. Serious dislocations, crop loss and destruction of any mechanical anti erosion devices can result from this form of mass movements. Due to drastic changes in hydrological conditions experienced by land naturally prone already to slipping and cleared for agriculture for the first time land slippage would be of common experience (Ahmad 1987; Ahmad 1990). Gullying is another common form of soil erosion that occurs on steep land bcause of the terrain involved. This is more common on sandy soils, volcanic soils and vertisols, which are all porous materials. Soils easily attain saturated conditions upon the rapid entry of water, consequently breaking the material and ultimately, leading to the formation of gullies. Agricultural activities enables this soil erosion in steeplands by allowing rapid soil wetting upon the start of the wet season. Farming activities though unsuitably oriented field boundaries, foot tracks and the lack of provision for disposal of surface water are some main causes of gullying, even on soils not prone to this tpe of steepland soil erosion (Ahmad 1987;Ahmad 1990). Since steeplands are traditionally considered marginal for agricultural crop production, most research on soil erosion and soil conservation has been done on either flat land or rolling land with a maximum slope of about 20%'(Lal, 1988). 2.5 Factors Affecting Soil Erosion The causes of soil erosion have been intensively discussed during the past 40 years. Soil erosion is a natural process that is enhanced by human activity (Richter, 1998) and occurs in all landscapes and under different land uses. In addition to human activities, soil erosion processes are also caused by morphometric characteristics of the land surface, the erosive forces of rainfall and the erodibility of soils and soil surfaces. When rainwater reaches the soil surface it will either enter the soil or run off. Runoff occurs when the rainfall intensity exceeds the infiltration capacity of the soil. Water erosion is the result of the dispersion action of rain drops, the transporting power of water and also the vulnerability of the soil to dispersion and movement (Baver and Gardner, 1972). The effects of soil erosion is also classified: definition of gullies and explanation of gully development is given by Morgan (1996), as well as Hudson (1995) who additionally focuses on individual cases of the development of gullies. Toy et al (2002) give detailed definitions of soil erosion features and processes such as sheet erosion and inter-rill erosion, rill erosion, as well as ephemeral and permanent gully erosion. Rill erodibility depends both directly and indirectly on soil properties such as bulk density, organic carbon and clay content, clay mineralogy, cations in the exchange complex, soil pH and experimental conditions such as moisture content, aging of prewetted soil and quality of eroding water (Rapp,1998). Govers (1990) found that runoff erosion resisitance of a loamy material was extremely sensitive to variation in the initial moisture content and to a lesser extent to changes in bulk density. The process of water erosion can be separated into two components, rill and interrill erosion (Young and Onstad, 1978). Interrill erosion (sheet erosion) is mainly caused by raindrop impact and removes soil in a thin almost imperceptible layer (Foster, 1989). In interril erosion the flow of water is generally unconfined, except between soil clods and covers much of the soil surface. As the velocity of flow increases the water incises into the soil and rills forms (Evans,1980). Rill erosion begins when the eroding capacity of the flow at some point exceeds the ability of the soil particles to resistant detachment by flow (Meyer cited by Rapp, 1998). Soil is detached by headcut advance from knickpoints (De Ploey, 1989; Bryan, 1990), rill slide sloughing and hydraulic shear stress (Foster cited by Rapp, 1998) as well as by slumping by undercutting of side walls and scour hole formation (Van Liew and Saxton, 1983). These processes are usually combined into a detachment prediction equation as a function of average shear stress (Foster cited by Rapp, 1998). When the rills develop in the landscape, a three to five fold increase in the soil loss commonly occurs (Moss, Green and Hutka 1982 and Meyer and Harmon 1984). 2.5.1 Vegetative Factors The effects of vegetation can be classified into three catergories: The interception of raindrops by the canopy (DHuyvetter, 1985). Two effects are associated with this. Firstly, part of the intercepted water will evaporate from the leaves and stems and thus reduce runoff. Secondly, when raindrops strike the vegetation, the energy of the drops is dissipated and there is no direct impact on the soil surface. The interception percentage depends on the type of crop, the growth stage and the number of plants per unit area. A well distributed, close growing surface vegetative cover will slow down the rate at which water flows down the slope and will also reduce concentration of water (DHuyvetter, 1985). As a result, it will decrease the erosive action of running water. There is also the effect of roots and biological activity on the formation of stable aggregrates, which results in a stable soil structure and increased infiltration that reduces runoff and decreases erosion (DHuyvetter, 1985). Increased permeability also reduces erosion as a result of in increased water percolation due to better drainage. Stables aggregrates in the topsoil also counteract crusting. 2.5.2 Rainfall Factors Raindrop size, shape, duration of a storm and wind speed interactions controls the erosive power of rainfall (DHuyvetter, 1985). The erosivity of rainfall is expressed in terms of kinetic energy and is affected by various factors. According to Wischmeier and Smith (1965), the intensity of rainfall is closely related tot e kinetic energy, according to the regression equation E = 1.213 + 0.890 log I Where E = the kinetic energy (kg.m/m2.mm) I = rainfall intensity (mm/h) Raindrop size, distribution and shape all influence the energy momentum of a rainstorm. Laws and Parson (1943) reported an increase in median drop size with increase in rain intensity. The relationship between mean drop size (D50) and rainfall is given by: D50:2.23 I 0.182 (inch per hour). The median size of rain drops increases with low and medium intensity fall, but declines slightly for high intensity rainfall (Gerrard, 1981). The kinetic energy of an rainfall event is also related to the velocity of the raindrops at the time of impact with the soil (DHuyvetter, 1985). The distance through which the rain drop must fall to maintain terminal velocity is a function of drop size. The kinetic energy of a rainstorm is related to the terminal velocity according to the equation: Ek = IV2/2 Where Ek = energy of the rain storm I = Intensity V= Velocity of raindrop before impact Ellison (1945) developed an equation showing that the relationship between the soil detached, terminal velocity, drop diameter and rainfall intensity: E = KV4.33 d1.07 I0.63 Where E = relative amount of soil detached K = soil constant V = velocity of raindrops (ft/sec) d = diameter of raindrops (mm) I = rainfall intensity 2.5.2.1 Effect of rainfall intensity on runoff and soil loss According to Morgan (1995), soil loss is closely related to rainfall partly through the detaching power of raindrops striking the soil surface and the contribution of rain to runoff. If rainfall intensity is less than the infiltration capacity of the soil, no surface runoff occurs and the infiltration rate would equal the rainfall intensity (Horton, 1945) as sited by Morgan (1995). If the rainfall intensity exceeds the infiltration capacity, the infiltration rate equals the infiltration capacity and the excess rainfall forms surface runoff. According to Morgan (1995), when the soil is unsaturated, the soil matric potential is negative and water is held in the capillaries due to matrics suction. For this reason, under saturated conditions sands may produce runoff very quickly although their infiltration capacity is not exceeded by the rainfall intensity. Intensity partially controls hydraulic conductivity, increasing the rainfall intensity may cause conductivity to rise so that although runoff may have formed rapidly at relatively low rainfall intensity, higher rainfall intensities do not always produce greater runoff (Morgan, 1995). This mechanism explains the reason why infiltration rates sometimes increase with rainfall intensities (Nassif and Wilson, 1975). 2.5.3 Soil Factors According to Baver et al, (1972), the effect of soil properties on water erosion can be in two ways : Firstly, certain properties determine the rate at which rainfall enters the soil. Secondly, some properties affect the resistance of the soil against dispersion and erosion during rainfall and runoff. The particle size distribution is an important soil property with regards to erodibility. Generally it is found that erodible soils have a low clay content (DHuyvetter, 1985). Soils with more than 35% clay are often regarded as being cohesive and having stable aggregates which are resistant to dispersion by raindrops (Evans, 1980). Evans also stated that sands and coarse loamy sands are not easily eroded by water due to its high infiltration rate. In contrast soils with a high silt or fine sand fraction are very erodible. Erodibility of soil increases with the proportion of aggregates less than 0.5mm (Bryan, 1974). Factors which contribute to aggregate stability include organic matter content, root secretions, mucilaginous gels formed by break down of organic matter, the binding of particles by sesquioxides and the presence of a high Ca concentration on the exchange sites of the colloids instead of a high sodium content (DHuyvetter, 1985). The depth of erosion is determined by the soil profile (Evans, 1980). According to Evans soil horizons below the A horizon or plough layer are often more compact and less erodible. The texture and chemical composition of the sub surface horizon can also have an adverse effect. Normally deep gullies can be cut if the parent material is unconsolidated. If resistant bedrock is near the surface only rills will develop. Soil rich in surface stones are less susceptible to erosion (Lamb, 1950 and Evans, 1980). Stones protect the soil against erosion and also increase the infiltration of the flowing water into the soil. The antecedent soil moisture and the surface roughness are both regarded by Evans (1980) as important soil factors affecting erosion. The ability of a soil to accept rainfall depends on the moisture content at the time of the rainfall event. 2.5.3.1 Factors affecting aggregate stability Soil structure is determined by the shape and size distribution of aggregates. Aggregrate size and strengthe determine the physical properties of a soil and its susceptibility to breakdown due to water forces. Their stability will have a decisive effect on soil physical properties (Lynch and Bragg, 1985). The main binding materials giving stable aggregates in air dry state are the glueing agents in organic matter (Chaney and Swift, 1984; Tisdale and Oades, 1982) and sesquioxides (Goldberg and Glaubic, 1987). 2.5.3.1.1 Aluminium and Iron Oxides The soil used by Kemper and Koch (1966) contained relatively little free iron, although it did contribute to aggregrate stability. Their data show a sharp increase of free iron from 1 to 3%. Goldberg and Glaubic (1987) concluded that Al-oxides were more effective than Fe-oxides in stabilizing soil structure. Al-oxides have a greater proportion of sub-micrometer size particles in a sheet form as opposed to the spherical form of Fe-particles. Shainberg, Singer and Janitzky (1987) compared the effect of aluminium and iron oxides on the hydraulic conductivity of a sandy soil. 2.5.3.1.2 Organic Matter Organic matter can bind soil particles together into stable soil aggregates. The stabilizing effect of organic matter is well documented. Little detailed information is available on the organic matter content required to sufficiently strengthen aggregates with ESP values greater than 5 or 7, and containing illite or montmorrillionite, so as to prevent their dispersion in water (Smith, 1990). High humus content makes the soil less susceptible to the unfavourable influence of sodium (Van den Berg, De Boer, Van der Malen, Verhoeven, Westerhof and Zuur, 1953). Kemper and Koch (1966) also found that aggregate stability increased with an increase in the organic matter content of soils. A maximum increase of aggregate stability was found with up to 2% organic matter, after which aggregate stability increased very little with further increases in organic matter content. 2.5.3 Slope Factors Slope characteristics are important in determining the amount of runoff and erosion ( DHuyvetter, 1985). As slope gradient increases, runoff and erosion usually increases (Stern, 1990). At low slopes due to the low overland flow velocities, detachment of soil particles from the soil surface into the water layer is due to detachment alone (Stern, 1990). Additionally, at low slope gradients, particles are splashed into the air in random directions unlike the case with steeply sloping land where down slope splash occurs (Watson and Laflen, 1985). As slope gradient increases, the ability for surface runoff to entrain and transport sediments increases rapidly until the entrainment by the surface runoff becomes dominant contributing to sediment transport (Stern, 1990). Foster , Meyer and Onstad (1976) presented a conceptual model that showed that at lower slopes, interill transport determined erosion, while at steeper slopes, raindrop detachment determined it. Th uniform bed characteristics of sheet flow transport tend to be replaced by channels because of instability and turbulent flow effects (Moss, Green and Hutka, 1982). There are many empirical relationships relating soil transport by surface wash to slope length and slope gradient. Zingg (1940) showed that erosion varied according to the equation: S = X1.6 tanB1.4 Where S = soil transport cm/yr X = slope length (m) B = slope gradient (%) Studies conducted by Gerrard (1981), showed that plane and convex slopes did not differ significantly in the amount of soil lost by surface runoff, but concave slopes were less eroded. Some researchers such as Zingg (1940) and Mc Cool et al (1987) indicated that soil erosion increases exponentially with increase in slope gradient. The relationship is indicated after Zing (1940) by: E = aSb where E is the soil erosion, S is the slope gradient (%) and a and b are empirical constants. The value of b ranges from 1.35 to 2.0. The other relationship between erosion and slope gradient for inter-rill erosion is given by Mc Cool et al (1987) E = a sin b Q+C Q is the slope angle in degrees A,b and C are empirical constants. However, even if the effect of slope gradient on erosion is well recognized, several studies indicate that the power relationship between slope gradient and soil loss over predicts interrill erosion rate by as much as two or more times (Torri, 1996;Fox and Bryan, 1999), and the relationship is better described as linear. 2.8 Soil Erosion Impacts 2.8.1 Soil Physical Properties Progressive soil erosion increases the magnitude of soil related constraints for crop production. These constraints can be physical, chemical and biological. The important physical constraints caused by erosion are reduced rooting depth, loss of soil water storing capacity (Schertz et al 1984; Sertsu, 2000), crusting and soil compaction and hardening of plinthite (Lal, 1988). Erosion also results in the loss of clay colloids due to preferential removal of fine particles from the soil surface (Fullen and Brandsma, 1995). The loss of clay influences soil tilth and consistency. Exposed subsoil is often of massive structure and harder consistency than the aggregated surface soil (Lal, 1988). Development of rills and gullies may change the micro-relief that may make use of farming machinery difficult. Another effect of erosion is that the manangement and timing of farm operations. 2.8.2 Soil Chemical Properties Soil erosion reduces the fertility status of soils (Morgan, 1986; Williams et al., 1990). Soil chemical constraints and nutritional problems related to soil erosion include low CEC, low plant nutrients (NPK) and trace elements (Lal, 1988; Fullen and Brandsma, 1995). Massy et al (1953) reported an average loss of 192 kg of organic matter, 10.6 kg of N and 1.8kg per ha on a Winsconsin soils with 11% slope. Sharpley and Smith (1990) reported that the mean annual loss of total P in runoff from P fertilized watersheds is equivalent to an average of 15%, 12% and 32% of the annual fertilizer P applied to wheat, mixed crop grass and peanut sorghum rotation practices respectively. Researchers (Massy et al 1953; Lal, 1975) have also reported extensive loss of N in eroded sediments. 2.8.3 Productivity Quantifying the effects on crop yields is a difficult task. It involves the evaluation of interactions between soil properties, crop characteristics and climate. The effects are also cumulative and not observed until long after accelerated erosion begins. The degree of soil erosions effects on crop yield depends on soil profile characteristics and management systems. It is difficult to establish a direct relationship between rates of soil erosion and erosion induced soil degradation on the one hand and crop yield on the other (Lal, 1988). It is well known that soil erosion can reduce crop yields through loss of nutrients, structural degradation and reduce of depth and water holding capacity (Timilin et al, 1986; Lal,1988). Loss of production in eroded soil further degrades its productivity which in turn accelerates soil erosion. The cumulative effect observed over a long period of time may lead to irreversible loss of productivity in shallow soils with hardened plinthite or in soils that respond to expensive management and additional inputs (Lal,1988). 2.8.4 Off Site Effects of Soil Erosion. Effects of erosion include siltation of rivers, crop failure at low lying areas due to flooding, pollution of waterbodies due to the various chemicals brought by the runoff from different areas. Several studies reported the significance of the off site effects of soil erosion on land degradation (eg. Wall and ven Den,1987; Lo, 1990; Robertson and Colletti, 1994; Petkovic et al, 1999) Rainwater washes away materials that originate from fertilizers and various biocides (fungicides, insecticides, herbicides and pesticides) which are applied in large concentrations. They reappear in greatr quantities in the hydrosphere polluting and contaminating the water environment (Zachar,1982;Withers, and Lord, 2002; Verstraeten and Poesen, 2002). Chemical pollution of water mainly by organic matter from farm fields causes rapid eutrophication in waterways (Zachar, 1982;Zakova et al, 1993; Lijklema, 1995). 2.8.5 Soil Erosion Models Modelling soil erosion is the process of mathematically describing soil particle detachment, transport and deposition on land surfaces (Nearing et al, 1994). Erosion models are used as predictive tools for assessing soil loss and project planning. They can also be used for understanding erosion processes and their impacts (Nearing et al 1994). There are three main types of models, empirical or statistical models, conceptual models and physically based models (Morgan 1995, Nearing et al 1994, Merritt et al 2003). It is important to note however that there is no sharp difference among them. 2.8.5.1 Physically Based Models These models are based on solving fundamental physical equations describing stream flow and sediment and associated nutrient generations in a specific catchment (Merritt et al ., 2003). They are developed to predict the spatial distribution of runoff and sediment over land surfaces during individual storms in addition to total runoff and soil loss (Morgan, 1995). Physically based models are also called process based models (Morgan, 1995) as they rely on empirical equations to determine erosion processes. These models use a particular differential equation known as the continuity equation which is a statement of conservation of matter as it moves through space over time. The common physically based models used in water quality studies and erosion include : The Areal Non-Point Source Watershed Environment Response Simulation (ANSWERS) (Beasley et al., 1980), Chemical Runoff and Erosion from Agricultural Management Systems (CREAMS) (Knisel, 1980), Griffith University Erosion System Temp late (GUEST) (Misra and Rose, 1996), European Soil Erosion Model (EUROSEM) (Morgan, 1998), Productivity, Erosion and Runoff, Functions to Evaluate Conservation Techniques (PERFECT) (Littleboy et al., 1992) and Water Erosion Prediction Project (WEPP) (Laflen et al., 1991). 2.8.5.2 Empirical Mode

Racism in Brazil

Introduction Racial disparity and discrimination is not a new concept to any nation. In fact, many were built on the back of slave labor, whether the slaves were indigenous peoples or imported bodies. While many nations have undertaken measures to overcome racial disparity, others have encouraged racial democracy. Brazil, a modern and industrialized nation, suffers from racial discrimination based on their position in the world economy and built on the Ideology of the past.History Brazier's history is rife with racism and slavery, dating back to Its discovery by Pedro Allover Cabal In 1500. Brazil was originally settled with the Intention of harvesting Broadloom. However, over time the profits from that were supplanted by sugar, Brazil became the leading producer of sugar In the Atlantic world. The production of all these exports meant cheap labor was needed. During this time, the Portuguese were sending between 4,000 and 5,000 slaves per year to Brazil from Angola and West Africa: b y the 18th century, one million slaves had been imported (117).The continually shifting landscape meant that Brazier's exports continued to shift. By the time the 1 9th century came around, Brazier's major export was coffee as sugar reduction had shifted to the Caribbean Islands. The continued influx of European slaves and citizens resulted in an uneven population. European labor was generally more skilled and slowly began to overtake slave labor. Around this same time, the abolition of slavery happened in 1888, resulting in a decline in the slave population.By 1888, it was estimated that only a half-million people were slaves, compared to the one-and-a-half million slaves in 1872 (117). This is in part due to the fact that the coffee production process became more and more elaborate, requiring those with pesticides skills to take over. Coffee production soon fell into the hands of a wave of European immigrants, not freed slaves (122). The slaves that were freed often became vagrant s, homeless, Jobless and penniless (Roach, â€Å"Analysis: Brazier's ‘racial democracy†). The history of Brazil continues to inform the current day Brazil.The current day population of Brazil tops 160 million, with about half of that being black. Yet, the black population is nearly absent from all levels of power, meaning â€Å"government, congress, senate, the Judiciary, the higher ranks of the civil service and he armed forces† (Roach, â€Å"Analysis: Brazier's ‘racial democracy†). In 1999, the Minority Rights Group International reported that â€Å"black and mixed race Brazilian still have higher Infant mortality rates, fewer years of schooling, higher rates of unemployment, and earn less for the same work.Black men are more likely to be shot or arrested as crime suspects, and when found guilty, get longer sentences† (Roach, â€Å"Analysis: Brazier's ‘racial democracy†). Racism Persists There are many theories as to why racism continues to persist In modern day Brazil. One thing to look at Is their placement wealth the greater world economy. 22). When the Portuguese settled Brazil, they created a line of trade that focused on Portuguese and the plantation owners became very wealthy, all at the expense of the nearly three million black and mulatto slaves.A truly capitalist world is one that where each countries worth is weighed in terms of their strengths (military, trade, financial, production) and what they can contribute. A superpower such as the United States is naturally more diverse, which means that tolerance and racism are not tolerated as easily in modern day society. Core countries are those that have the retreat strengths and the peripheral countries are the ones that are expendable. Phillips says â€Å"the peripheral countries were exploited by the core, and ‘semi peripheral' countries were exploited by the core and exploited peripheral countries.The relations between these three geopoli tical units are ones built on inequality' (122). Phillips goes on to say that â€Å"similar to the inequality that can be seen in a class system within a country, this template is now spread around the globe to view inequality on a world scale† (122). In other words, Brazil is treated with discrimination based on their trade abilities and overall contribution. This has trickled down so that individuals are also being treated with the same discrimination.It is also important to note that â€Å"racism is fundamentally rooted in processors class structures, historically shifting modes of production, distribution, and consumption, and increasingly, in the unequal exchanges that tie local political economies to the global processes of capitalism† (Phillips 122). Brazier's history of racial prejudice and discrimination has established a mode of living and ideology that persists to this day. It would be too easy to blame slavery on the world economy, but it is safe to say tha t he capitalist world economy has helped perpetuate racial prejudice and discrimination.Slavery existed long before profit was exchanged for labor. As Brazil has grown, â€Å"the means to social mobility after emancipation was closely guarded by the Brazilian white ruling class, who allowed for a pool of relatively less expensive labor consisting mainly of Brazilian natives and other European immigrants† (122). The influx of cheap European labor resulted in the black and mulatto population being pushed aside. After Brazil abolished slavery, the ex-slaves were left with two hoicks: work under the same conditions as when they were slaves or Join the masses of unemployed (Phillips 122).They had additional challenges; they were competing with native Brazilian and European immigrants for a limited number of jobs where the new economic order was wage labor (122). Racism played a major role after the emancipation of the slaves as many of the ex-slaves were discriminated against in t he free Job market. While the shift has been to the detriment of blacks and mulattos, racism has not helped the white population of Brazil (123). Despite the racism running rampant, there is no black movement in Brazil. There is seemingly no racial tension or conflict.Blacks that live in Salvador, who make up 80% of the population, say they feel safer in that environment than they do in the US (Roach, â€Å"Analysis: Brazier's ‘racial democracy'). It is speculated that this is because appearances matter more in Brazil than heritage. In the US, one drop of black ancestry means you are black, while in Brazil, if you appear white, you are perceived as white (Roach, â€Å"Analysis: Brazier's ‘racial democracy'). It can also be noted that the US has a history of violent racism where oppressed populations were treated harshly. Those past grievances have not been forgotten, and in some cases, not forgiven freedom.It would seem as though the US operates under a shadow of racis m, attempting to sweep it under the rug and pretend that equality is real. Brazil does not operate under such false pretenses. Racism is alive and acknowledged. As of the 2010 census, 51% of Brazil identifies itself as black or brown. The government estimates that the income of white Brazilian is more than double that of black or brown Brazilian and that blacks are at a distinct disadvantage in relation to education and access to healthcare (â€Å"Brazilian 2010 Census Highlights Racism Problem†). The racial divide in Brazil is based on a social pyramid.Many will argue that the black community is poor because class, not race, stratifies their society. However, there are many that would disagree. According to Mario Theodore, an activist for social equality believes that â€Å"slavery legacy of injustice and inequality can only be reversed by affirmative action policies, of the kind found in the United States† (â€Å"Race in Brazil: Affirming a Divide†). Yet, it i s also fair to note that in the US, there are many of different races that are in positions of great power and that social class is often dictated by wealth.The history of the US supports the advancement of the white race, but progress is showing that race is beginning to take a backseat to skill set and overall acumen. In Brazil, the race line is well drawn. Most of those in the public eye, such as TV news anchors, doctors, dentists, fashion models, and lawyers are all white. The majority of black and mulatto's are working in the â€Å"blue collar† trade, often deemed the unskilled labor pool. The salary disparity is even more telling. By 2011, the average black or brown worker was earning of what the average white worker made (â€Å"Brazilian 2010 Census Highlights Racism Problem†).Statistics do not differentiate between gender, only race, though it can be assumed that the same problem occurs between gender lines. Affirmative Action Brazil, once considered a â€Å"r acial democracy' is fighting hard to shed that moniker. Racial democracy, in relation to Brazil, is defined as the thought that compared to other nations; racism was actually very minimal in Brazil (Tells, â€Å"Discrimination and Affirmative Action in Brazil†). However, today, most Brazilian concur that Brazil is victim to racial prejudice and discrimination.Blacks and mulattos are the major cities of widespread police violence and often earn half the income of their white counterparts. In addition, television and advertising portray Brazilian society as one that is almost entirely white (Tells, â€Å"Discrimination and Affirmative Action in Brazil†). This is because the working class and elite are almost entirely white, so the melting pot of races exists only in the working class and poor. According to Antonio Riser's, a sociologist, â€Å"It's clear that racism exists in the US. It's clear that racism exists in Brazil.But they are different kinds of racism† ( â€Å"Race in Brazil: Affirming a Divide†). He continues to argue that the racism itself is nefarious and veiled, unlike the racism that used to run rampant in the US. In Brazil, there was never a UK Klux Klan or enforced segregation or even a ban on interracial marriage (â€Å"Race in Brazil: Affirming a Divide†). Affirmative action is often put into place to attempt to create a racially diverse atmosphere. Most often this is in correlation to the workplace where employers do not discriminate based on race, gender, or religious affiliation.In Brazil, the new affirmative action can be most notably seen in the university setting. By 2008 almost 50% of Brazilian universities have a race-based affirmative action attend a university, students were required to pass a standardized test. Now, leading universities are mandated to allow a fixed percentage of nonwhite students to attend. In addition, they have quotas for indigenous peoples and for the disabled (Tells, â€Å"Dis crimination and Affirmative Action in Brazil†). Even though affirmative action was put in place to help, it is not without controversy.Those that oppose the policies include â€Å"much of the media, private school students, their parents and the schools themselves, scholars and artists who alee the racial democracy ideal and even black students who believe in meritocracy' (Tells, â€Å"Discrimination and Affirmative Action in Brazil†). They maintain that affirmative action does nothing to further racial equality; instead, it merely promotes racial equality without any substance. In addition, many academics are fighting against affirmative action in schools and campaigning against quotas.They argue that enforcing affirmative action is, in itself, inherently an act of racism. It divides people into arbitrary color categories; a feat, which is not as easy as it seems nice much of Brazil, is a country of mixed race (â€Å"Race in Brazil: Affirming a Divide†). They a lso argue that it undermines the equality of the admissions process, even though in the past, nepotism and whom you know have been the quickest routes to advancement (â€Å"Race in Brazil: Affirming a Divide†).Despite these arguments, studies have shown that many of the â€Å"quota† students are performing academically as well or better than their white counterparts. This can be attributed to the fact that many of those white students were admitted because they had the means and money to prepare for the entrance exam (â€Å"Race in Brazil: Affirming a Divide†). The next target is the labor market, a place where affirmative action could show positive benefits. In the United States, only 12% of the population is black, yet we have a black president, numerous black politicians and millionaires.In contrast, Brazil has a limited number of black people in positions of power. Because of this, some private sector companies are making racial diversity a requirement in th eir recruiting process (â€Å"Race in Brazil: Affirming a Divide†). But again, the same problem occurs that showed up in the university setting. Just because a person is off different race does not mean they are qualified for the Job at hand. It often follows that work production and quality decline because employers are hiring based on color, not skill level.Unlike the US, affirmative action in Brazil is being done in a very Brazilian way. There is little to no government interference or enforcement. Universities and private companies are making their own policies. The Supreme Court is involved, but is slow to act in hopes that society will figure out their own issues (â€Å"Race in Brazil: Affirming a Divide†). Society is moving fast though. Businesses and advertisers are now targeting black populations, but changing the minds of the consumer sector is n easy task compared to changing the mindset of racism ingrained after years and years of overt racism.Many Brazilia n assume that blacks and browns belong on the bottom of the social ladder, making the push for proactive change difficult (â€Å"Race in Brazil: Affirming a Divide†). Solution? In order for Brazil to pull down the racial divide and move beyond racial democracy, the boundaries between black and white need to be weakened. There is but despite this, the racial division is not nearly as rigid as they are in the US. An interesting note is that most Brazilian perceive their culture to be an example how ace and culture can coexist peacefully.Despite this somewhat astonishing claim, it is still believed that 90% of the white population is prejudiced against the black and mulatto population. However, their idea of racism differs greatly from person to person so it is difficult to Judge what this really means. In a recent event in Brazil, a six-year-old boy was kicked out of a pizza polar supposedly for the color of his skin. According to the restaurant manager, he mistook the young bo y as a local street boy. The boys parents have since then filed a complaint with the local police department ND are also considering taking legal actions.This story launched a huge race-debate in Brazil (Phillips â€Å"Does Brazil Have a Race Problem†). While stories like this continue to gain traction, it is hard to figure out where Brazil goes from here. Affirmative action plans seem like a step in the right direction, but that will not be enough to change 500 years in ingrained behavior. Brazil will need a complete economic and social shift if it wishes to eradicate racism. If the US is a learning curve, Brazil has a lot of work to do, and so does the US when it comes down to reality. ConclusionMany people around the world see Brazil as a country full of racial diversity where racism Just simply does not exist, where as others claims Brazil suffers from invisible racism where blacks earn less, live less, and are educated less. Although blacks make up for most of the popula tion in Brazil they are still grossly under-represented in higher education, media, and politics. The continued racial divide will only be removed when government and individuals work together to not only acknowledge the problem, but find a way to move above and beyond racism and look at the individual for the value, not their skin color.

Fundamentals of Anatomy & Physiology (9th Edition)

Exam 1 Review Guide: (Introduction to Anatomy, Chemistry, Cell) Note: 90 % of the exam will come from this review guide. 10% will come from masteringaandp. com, the text or material covered in the lecture and not posted on the lecture slides. Introduction to Anatomy †¢ What is the definition of anatomy? †¢ What is the definition of physiology? †¢ What is homeostasis? †¢ What are the two ways in which homeostasis is maintained? †¢ What are the directional terms used to find things in the body? o For example, what are the medical terms for the following? o Up/down o Right/left o Close/far Closer to the midline/farther from the midline o Same side/opposite side o Face up/face down o Etc. (maybe more) †¢ What are the major cavities of the body? †¢ What are the planes of the body? †¢ What are the body regions? o For example, what are the medical terms for the following? o Arm o Forearm o Wrist o Hand o Fingers o Thumb o Elbow o Front of elbow o Poin t of elbow o Thigh o Knee o Knee cap o Leg o Calf o Foot o Sole of foot o Head o Neck o Chest o Lungs o Heart o Groin o Pelvis (front) o Low back o Buttocks o Etc. (maybe more) †¢ What are the four abdominal quadrants and what major organs are found in each quadrant? What are the levels of organization and what is the order? Chemistry †¢ What are the four major elements of the body? †¢ What are the lesser or trace elements of the body? †¢ What are the three subatomic particles and what charge do they carry? †¢ What is an isotope? †¢ What is the difference between an atom and an element? †¢ What are the three major types of chemical bonds? How do they differ? o Give examples for each. †¢ What three atoms are associated with hydrogen bonding? †¢ What are the two major types of chemical reactions? †¢ Do you make or use energy when you make a bond? Break a bond? What is the difference between a catalyst and an enzyme? †¢ What is the major atom/element contained in organic compounds? †¢ What is an acid? †¢ What is a base? †¢ What is pH the measure of? †¢ If aspirin is a weakly acidic drug, where is it most likely to be absorbed in the gastrointestinal tract? Why? †¢ Is lemon juice an example of an acid or a base? †¢ Is household chlorine an example of an acid or a base? †¢ What are the four major types of organic compounds? †¢ What are examples of monosaccharides, disaccharides, and polysaccharides? †¢ What are examples of lipids? †¢ What are examples of proteins? What are the building blocks of proteins? †¢ What do proteins contain that carbohydrates and lipids do not? †¢ What are the two major types of nucleic acids? †¢ What are the two major types of purines? †¢ What are the three major types of pyrimidines? †¢ Which purines are bonded to which pyrimidines? How many hydrogen bond hold them together? †¢ What is DNA? †¢ What i s RNA? †¢ What are the nucleotides (chains of nucleic acids) composed of? †¢ What are the two major parts of metabolism? †¢ What are the high compounds which store energy? Cells †¢ What is the plasma membrane composed of? What is the function of the plasma membrane? †¢ What are the two different types of plasma membrane proteins? †¢ What are the three functions of membrane proteins? †¢ Where are glycolipids only found? †¢ What are the three major types of membrane junctions? o What are their functions †¢ What is osmosis? †¢ What is diffusion? †¢ What are the two major types? †¢ What is active transport? †¢ What are the major types? †¢ What is endocytosis/exocytosis? †¢ What are the different types of endocytosis? †¢ What is phagocytosis? †¢ What is pinocytosis? †¢ What is clathrin-mediated/receptor-mediated endocytosis? What is the cytoplasm? Cytosol? †¢ What are the major organelles of th e cell? †¢ What are their functions? o For example, what is the function of the following organelles? o Mitochondria o Peroxisomes o Lysosomes o Edoplasmic reticulum ? Smooth ? Rough o Golgi apparatus o Cytoskeleton o Centrioles o Ribosomes o Etc. (Maybe more) †¢ What are cilia? †¢ What is the nucleus? What does it contain? †¢ What is chromatin? †¢ What is the cell cycle? †¢ When is DNA replicated? †¢ What does the cell undergo cell division? †¢ What is mitosis? †¢ What are the phases of mitosis? What occurs during each phase? What is meiosis? How does it differ from mitosis? †¢ What are the phases of meiosis? †¢ What is transcription? From what to what? †¢ What is translation? From what to what? Tissues †¢ What makes up tissues? †¢ What are the 4 different types of tissues? †¢ What are the different types of epithelial tissues? †¢ How do you name the epithelial tissues? o Simple o Stratified o Pseudostr atified o Transitional o Squamous o Cuboidal o Columnar o Etc. (look for more) †¢ Where are these epithelial tissues located? †¢ What are the major functions of each? †¢ What is the difference between exocrine and endocrine glands? Where do you find goblet cells? †¢ What is the function of goblet cells? †¢ What are the different types of exocrine glands? (Structures) †¢ What is the difference between merocrine and holocrine glands? †¢ What are the different types of connective tissues? o Loose o Areolar o Adipose o Reticular o Dense o Regular o Irregular o Cartilage (Hyaline, Elastic, Fibrous) o Bone (Osseous) o Blood †¢ What are their (above) functions and where are they found? †¢ What 3 structural elements make up connective tissue? †¢ What are the characteristics of nervous tissue? †¢ What are the 3 different types of muscle tissue? What the differences? What are the similarities? †¢ What are the characteristics for each ? †¢ What happens in tissue repair? Skin Tissue †¢ What are the 3 major regions of the skin? †¢ What are the 4 cells of the epidermis? What are their functions? †¢ What are the 4 or 5 layers of the epidermis? †¢ Where do you find stratum lucidum? †¢ What is also called the basal layer? What is also called stratum germinativum? o What do you find in this layer? †¢ What is also called the prickly layer? o What do you find in this layer? †¢ What is also called the granular layer? o What do you find in this layer? What is also called the clear layer? o What do you find in this layer? †¢ What is also called the horny layer? o What do you find in this layer? †¢ Is the epidermis vascular? †¢ What are the 2 major divisions of the dermis? o What do you find in each layer? †¢ What do you find in the hypodermis or subcutaneous layer? †¢ What are the 3 pigments that contribute to skin color? †¢ What are the 4 different types of sweat glands? Where do you find each? †¢ What are sebaceous glands? †¢ Where do you find hair? o What is its function? o What is its structure? o What is the hair follicle? What are the 2 different types of hair and when or where are they found? o What is alopecia and what are some ways to treat it? †¢ What are nails? o What is its structure? †¢ What are some of the functions of the integumentary system? †¢ What are the 3 major types of skin cancer? o What are the degrees of severity? o What is the most dangerous? o What is the ABCD rule? †¢ What are burns? o What is a first degree burn? Example? o What is a second degree burn? Example? o What is a third degree burn? Example? o What is the rule of NINES? Bone Tissue †¢ What type of tissue is cartilage? o Structure? Function? †¢ What makes up cartilage? o Ground substance? o Fibers? o Cells? †¢ What are the 3 different types of cartilage? o Where do you find each type? †¢ What are the different types of growth for cartilage and which direction do they occur? o Appositional o Interstitial †¢ Is cartilage vascular? †¢ What are the 2 major divisions of the skeleton? †¢ What are the 4 major shape classifications for bone? †¢ What are some major functions of bone? †¢ What are the major bone markings and how are they described? o Tuberosity o Crest o Trochanter o Line o Tubercle o Epicondyle o Spine o Process Head o Facet o Condyle o Ramus o Meatus o Sinus o Fossa o Groove o Fissure o Foramen †¢ What is: o Diaphysis? o Epiphysis? o Metaphysis? o Epiphyseal line? o Periosteum? o Medullary cavity? †¢ Is bone vascular? †¢ What type of tissue is bone? o Structure? o Function? †¢ What makes up bone tissue? o Ground substance? o Fibers? o Cells? †¢ What types of bones contain spongy bone? †¢ What is the function of red bone marrow? o In infants? o In adults? †¢ What is the function of yellow bone marrow? †¢ What is the functional (or basic) unit of the bone? †¢ What are Haversian systems (or osteons)? What are: o Lamella o Haversian (central) canals o Volkmann’s canals o Canaliculi o Osteocytes o Osteogenic cells o Osteoblasts o Osteoclasts †¢ What do you find in lacunae? †¢ What is endochondral ossification and where does it occur? o What are the 5 stages? †¢ What is intramembranous ossification? Example? †¢ What are the functional zones in long bone growth? o What are the 3 zones? †¢ How does growth hormone (GH) affect bone growth before puberty (and epiphyseal growth plate closure)? †¢ How does growth hormone (GH) affect bone growth after puberty (and epiphyseal growth plate closure)? What are the two hormones released at puberty? o What type of closure occurs as a result? o What type of growth does this closure end? †¢ What is the difference between bone deposition and resorption? †¢ What is calcium used for? †¢ What is the function of calcitonin? o Where does it come from? †¢ What is the function of parathyroid hormone? o Where does it come from †¢ What is Wolff’s law? †¢ Fractures? o Comminuted o Compression o Spiral o Epiphyseal o Depressed o Greenstick †¢ What are the stages of bone healing? †¢ What is: o Osteomalacia o Rickets o Osteoporosis o Paget’s disease

The Battle Of Gettysburg And The Civil War Essay - 1448 Words

On July 1, 1863, the bloodiest, most gruesome war in American History began. The Battle of Gettysburg was fought in the small town of Gettysburg, Pennsylvania. The Union Army under the command of General George G. Meade faced the Confederate Army led by General Robert E. Lee. They clashed for a long, tragic, three days, but at a costly expense of human life. The American Civil War was one of the most significant battles that the United States has ever been engaged in. On the lines, there were brothers lined up across from one another, fighting against each other. Over the course of the five years of war, a total of 620,000 American lives was lost. This was one of the most tragic events that our nation has ever been involved in, that our own people were killing each other for what they believe in. On the first day of the Battle of Gettysburg, isolated units of the Army of Potomac and the Army of Northern Virginia began to engage. Union General, John Buford, was in command of two briga des of cavalry. These were the first troops to arrive at Gettysburg. Upon arriving, Buford dismounted his troops on foot and set them up in a defensive position on McPherson’s Ridge. He knew that his troops could not hold off an attack from the Confederates, so â€Å"his main goal was to buy some time until the rest of the Union Army could arrive.† (Foster 1). A few skirmishes erupted and quickly became more and more intense. The next day, battles emerged all over the Union’s lines. One of the mostShow MoreRelatedThe Battle Of Gettysburg And Civil War1375 Words   |  6 PagesThe Battle of Gettysburg occurred July 1-3, 1863 in and around Gettysburg, Pennsylvania and was one of the most significant battles of the American Civil War. Union forces of the North, commanded by Major General George G. Meade met and fought the Confederate forces of the South, commanded by General Robert E. Lee. Many historians believe the battle was a large turning point in the Civil War in favor of the Union (Woodworth, 2008). However, this is disputable. The battle was also significantRead MoreThe Battle Of Gettysburg And The Civil War Essay1434 Words   |  6 Pagessmall town of Gettysburg, Pennsylvania, was awoken to the beginning of what was to be the turning point of the Civil War for the Union. It began as a small skirmish, but by its end it involved so many Americans to which would become one of the bloodiest battles ever taken place on Unites States soil. The Battle of Gettysburg was not only a turning point in the war. From July 1st to July 3rd, 1863, the most famous and most important Civil War Battle took place in the small town of Gettysburg, PennsylvaniaRead MoreThe Battle Of Gettysburg And The Civil War970 Words   |  4 Pagesago, our fathers brought forth on this continent a new nation, conceived in liberty and dedicated to the proposition that all men are created equal†. One of the most well-known and 16th president of the United States stated these words at the Battle of Gettysburg. A two-minute speech that made such an emotional and passionate impact on the men then and future. He created a dramatic tone to empower, motivate, and engage in the new found nation where men were created equal. A purpose of his speech wasRead MoreBattle Of Gettysburg : Gettysburg Of The American Civil War1465 Words   |  6 PagesShaJuan Ervin Dr.Seamen MIS 303-01 2/24/16 Battle of Gettysburg Day 3 The Battle of Gettysburg is widely known as the largest battle of the American Civil War. This crucial battle occurred over three days, July 1st to July 3, 1863 surrounding the town of Gettysburg. In this battle, General Robert E. Lee tactfully awaited the forces of General Meade’s Union. On July 1st the Confederates were exploited by the Union resulting in a loss. The following day, the Confederates gained ground by conductingRead MoreThe American Civil War: The Battle of Gettysburg985 Words   |  4 PagesGettysburg was fought during the Civil War between the Union Army of the Potomac led by General Meade, and the Confederate Army commanded by General R.E. Lee. The battle only was waged over the course of three days, but it would prove to be the most costly of the entire Civil War. In this paper, we will show how the Confederacy failed to identify certain principles of war, which lead them to incorrectly conduct a center of gravity and critical vulnerability analysis on t he Union. Because of thisRead MoreThe Battle Of Gettysburg And American Civil War924 Words   |  4 PagesThe Battle of Gettysburg was fought over the first three days in July 1863, in and around the town of Gettysburg, Pennsylvania, by Union and Confederate forces during the American Civil War. Confederate General Robert E. Lee led the Army of Northern Virginia, while Union Major General George Gordon Meade commanded the Army of the Potomac. The Battle of Gettysburg involved the largest number of casualties of the entire war and is often described as the war s turning point. With his army in highRead MoreThe Battle Of Gettysburg During The Civil War847 Words   |  4 Pagesin which Family members fought on opposing sides of the war, for example: the Culp Family from Pennsylvania, Crittenden Family from Kentucky. Even President Lincoln’s wife had members of her family that fought on opposing sides. This is the perfect example of people fighting for their own cause not just because there was a line drawn on a map. Before the Battle of Gettysburg even started many soldiers had fought side by side in multiple battles as US Soldiers, where many friendships were born. OnceRead MoreThe Battle Of Gettysburg And The American Civil War1993 Words   |  8 Pagesagree that the Battle of Gettysburg was the turning point in the American Civil War. Some even go as far to as to call it the â€Å"high water mark† of the Confederate States. What is known is that it represented the last time a coherent Confederate Army threatened northern soil. In fact, from Gettysburg forward, the Confederation of Southern States would be fighting a defensive/fighting retreat. Gettysburg was one of the bloodiest battles of the war, but there were many bloody battles during the AmericanRead More The Battle of Gettysburg as the Turning Point of the Civil War1603 Words   |  7 Pages  Ã‚  Ã‚  Ã‚  Ã‚  Gettysburg was the turning point of the American Civil War. This is the most famous and important Civil War Battle that occurred over three hot summer days, July 3, 1863, around the small market town of Gettysburg, Pennsylvania. More importantly Gettysburg was the clash between the two major American Cultures of their time: the North and the South. The causes of the Civil War, and the Battle of Gettysburg, one must understand the differences between these two cultures. The Confederacy had anRead MoreThe Battle Of Gettysburg As A Turning Point Of Civil War1048 Words   |  5 PagesResearch question: Why was the Battle of Gettysburg considered a tur ning point of Civil War and what are the economics impacts of the event during the time? I. Introduction This purpose of this paper is to show why the Battle of Gettysburg was considered a turning point in Civil War and what are the economics influences of the outcome during the time of the event. The influences on both North and South’s markets are studied and will be shown whether any changes were made during the turning point