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Doctor of Philosophy(PhD) / It is generally accepted that tree roots can reinforce soil and improve the stability of vegetated slopes. Tree root reinforcement is also recognised in riverbanks although the contribution that the roots make to bank stability has rarely been assessed due to the reluctance of geomorphologists to examine riverbank stability by geomechanical methods that allow for the inclusion of quantified biotechnical parameters. This study investigates the interaction between alluvial soil and the roots of four southeastern Australian riparian trees. It quantifies the amount and distribution of root reinforcement present beneath typically vegetated riverbanks of the upper Nepean River, New South Wales, and examines the effect of the reinforcement on the stability of these banks. The ability of a tree to reinforce the soil is limited by the spatial distribution of its root system and the strength that the roots impart to the soil during shear. These two parameters were determined for the following four species of native riparian tree: Casuarina glauca, Eucalyptus amplifolia, Eucalyptus elata, and Acacia floribunda. The four species all exhibit a progressive reduction in the quantity of root material both with increasing depth and with increasing lateral distance from the tree stem. In the vertical direction there are two distinct zones that can be described. The first occurs from between 0 and approximately 15 % of the maximum vertical depth and consists of approximately 80 % of the total root material quantity. In this zone the root system consists of both vertical and lateral roots, the size and density of which varies between species. The second zone occurs below approximately 15 % of the maximum vertical depth and consists primarily of vertical roots. The quantity of root material in this zone decreases exponentially with depth due to the taper of individual roots. The earth reinforcement potential in terms of both geometric extent and the quantity of root material expressed as the Root Area Ratio (RAR) varies significantly from species to species. E. elata exhibited the highest values of RAR in soil zones beneath it while E. amplifolia reinforced a greater volume of soil than any of the other species examined. The increased shear resistance (Sr) of alluvial soil containing roots was measured by direct in-situ shear tests on soil blocks beneath a plantation. For three of the species (C. glauca, E. amplifolia, E. elata) Sr increased with increasing RAR measured at the shear plane, in a similar linear relationship. The shear resistance provided by A. floribunda roots also increased with increasing RAR at the shear plane but at a much greater rate than for the other three species. This is attributable to A. floribunda’s greater root tensile strength and therefore pull-out resistance, as well as its smaller root diameters at comparative RARs which resulted in a greater proportion of roots reaching full tensile strength within the confines of the test. Tree roots fail progressively in this system. Therefore determining the increased shear strength from the sum of the pull-out or tensile strengths of all individual roots and Waldron’s (1977) and Wu et al’s (1979) simple root model, would result in substantial over estimates of the overall strength of the soil-root system. The average difference between Sr calculated in this manner and that measured from direct in-situ shear tests is 10.9 kPa for C. glauca, 19.0 kPa for E. amplifolia, 19.3 kPa for E. elata, and 8.8 kPa for A. floribunda. A riverbank stability analysis incorporating the root reinforcement effect was conducted using a predictive model of the spatial distribution of root reinforcement beneath riparian trees within the study area. The model is based on measurements of juveniles and observations of the rooting habits of mature trees. It indicates that while the presence of vegetation on riverbank profiles has the potential to increase stability by up to 105 %, the relative increase depends heavily on the actual vegetation type, density, and location on the bank profile. Of the species examined in this study the greatest potential for improved riverbank stability is provided by E. amplifolia, followed by E. elata, A. floribunda, and C. glauca. The presence of trees on banks of the Nepean River has the potential to raise the critical factor of safety (FoS) from a value that is very unstable (0.85) to significantly above 1.00 even when the banks are completely saturated and subject to rapid draw-down. It is likely then that the period of intense bank instability observed within this environment between 1947 and 1992 would not have taken place had the riparian vegetation not been cleared prior to the onset of wetter climatic conditions. Typical ‘present-day’ profiles are critically to marginally stable. The introduction of vegetation could improve stability by raising the FoS up to 1.68 however the selection of revegetation species is crucial. With the placement of a large growing Eucalypt at a suitable spacing (around 3-5 m) the choice of smaller understorey trees and shrubs is less important. The effect of riparian vegetation on bank stability has important implications for channel morphological change. This study quantifies the mechanical earth reinforcing effect of some native riparian trees, thus allowing for improved deterministic assessment of historical channel change and an improved basis for future riverine management.

Doctor of Philosophy(PhD) / It is generally accepted that tree roots can reinforce soil and improve the stability of vegetated slopes. Tree root reinforcement is also recognised in riverbanks although the contribution that the roots make to bank stability has rarely been assessed due to the reluctance of geomorphologists to examine riverbank stability by geomechanical methods that allow for the inclusion of quantified biotechnical parameters. This study investigates the interaction between alluvial soil and the roots of four southeastern Australian riparian trees. It quantifies the amount and distribution of root reinforcement present beneath typically vegetated riverbanks of the upper Nepean River, New South Wales, and examines the effect of the reinforcement on the stability of these banks. The ability of a tree to reinforce the soil is limited by the spatial distribution of its root system and the strength that the roots impart to the soil during shear. These two parameters were determined for the following four species of native riparian tree: Casuarina glauca, Eucalyptus amplifolia, Eucalyptus elata, and Acacia floribunda. The four species all exhibit a progressive reduction in the quantity of root material both with increasing depth and with increasing lateral distance from the tree stem. In the vertical direction there are two distinct zones that can be described. The first occurs from between 0 and approximately 15 % of the maximum vertical depth and consists of approximately 80 % of the total root material quantity. In this zone the root system consists of both vertical and lateral roots, the size and density of which varies between species. The second zone occurs below approximately 15 % of the maximum vertical depth and consists primarily of vertical roots. The quantity of root material in this zone decreases exponentially with depth due to the taper of individual roots. The earth reinforcement potential in terms of both geometric extent and the quantity of root material expressed as the Root Area Ratio (RAR) varies significantly from species to species. E. elata exhibited the highest values of RAR in soil zones beneath it while E. amplifolia reinforced a greater volume of soil than any of the other species examined. The increased shear resistance (Sr) of alluvial soil containing roots was measured by direct in-situ shear tests on soil blocks beneath a plantation. For three of the species (C. glauca, E. amplifolia, E. elata) Sr increased with increasing RAR measured at the shear plane, in a similar linear relationship. The shear resistance provided by A. floribunda roots also increased with increasing RAR at the shear plane but at a much greater rate than for the other three species. This is attributable to A. floribunda’s greater root tensile strength and therefore pull-out resistance, as well as its smaller root diameters at comparative RARs which resulted in a greater proportion of roots reaching full tensile strength within the confines of the test. Tree roots fail progressively in this system. Therefore determining the increased shear strength from the sum of the pull-out or tensile strengths of all individual roots and Waldron’s (1977) and Wu et al’s (1979) simple root model, would result in substantial over estimates of the overall strength of the soil-root system. The average difference between Sr calculated in this manner and that measured from direct in-situ shear tests is 10.9 kPa for C. glauca, 19.0 kPa for E. amplifolia, 19.3 kPa for E. elata, and 8.8 kPa for A. floribunda. A riverbank stability analysis incorporating the root reinforcement effect was conducted using a predictive model of the spatial distribution of root reinforcement beneath riparian trees within the study area. The model is based on measurements of juveniles and observations of the rooting habits of mature trees. It indicates that while the presence of vegetation on riverbank profiles has the potential to increase stability by up to 105 %, the relative increase depends heavily on the actual vegetation type, density, and location on the bank profile. Of the species examined in this study the greatest potential for improved riverbank stability is provided by E. amplifolia, followed by E. elata, A. floribunda, and C. glauca. The presence of trees on banks of the Nepean River has the potential to raise the critical factor of safety (FoS) from a value that is very unstable (0.85) to significantly above 1.00 even when the banks are completely saturated and subject to rapid draw-down. It is likely then that the period of intense bank instability observed within this environment between 1947 and 1992 would not have taken place had the riparian vegetation not been cleared prior to the onset of wetter climatic conditions. Typical ‘present-day’ profiles are critically to marginally stable. The introduction of vegetation could improve stability by raising the FoS up to 1.68 however the selection of revegetation species is crucial. With the placement of a large growing Eucalypt at a suitable spacing (around 3-5 m) the choice of smaller understorey trees and shrubs is less important. The effect of riparian vegetation on bank stability has important implications for channel morphological change. This study quantifies the mechanical earth reinforcing effect of some native riparian trees, thus allowing for improved deterministic assessment of historical channel change and an improved basis for future riverine management.

Made available in DSpace on 2015-03-26T13:55:17Z (GMT). No. of bitstreams: 1 texto completo.pdf: 444349 bytes, checksum: f3932e0fa2865322d04c35cf2c173be8 (MD5) Previous issue date: 2010-02-24 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The aim of this study was to determine whether assisted reproductive biotechnologies in vitro fertilization (IVF) and artificial insemination (AI) can interfere on the processes of puberty in young bulls when compared to those generated by natural mating, and measure biometric and seminal parameters of these animals obtained by different techniques applied to animal breeding. There were nine data collections using 189 Gyr animals, ranging in age from one day old to 24 months old. These animals were classified into three categories, according to the reproductive techniques in which they were generated, with groups 1, 2 and 3 were constituted by the animals generated, respectively, from IVF (61 animals), IA (106 animals) and natural mating (22 animals). The animals were raised under pasture conditions with concentrate supplementation and weaned at around 12 months of age. The puberty was determined by means of the physical and morphological characteristics of the semen. There was no significant difference between the three groups regarding age, weight characteristics and testicular biometric during puberty age, demonstrating that the type of biotechnology used in the animal production had no effect on the weight and reproduction development of the same. The young bulls reached puberty at 19.0 ± 2.8 months, weighing 264.0 ± 46.0 kg and 27.4 ± 3.4 cm of scrotal circumference (SC), proving to be sexually late. In this occasion, the groups of animals showed averages and standard deviations of 1.8 ± 1.0 ml for ejaculate volume (VOL), gross motility (TURB) of 0.9 ± 1.0 (0-5), motility (MOT) of 52.3 ± 22.8%, vigor of (VIG) 2.6 ± 0.6 (0-5), sperm concentration in the ejaculate (CONC) of 647.8 ± 858.6 ( x106 spermatozoa), major sperm defects (DMA) of 58.9 ± 31.5%, minor sperm defects (DME) of 13.6 ± 8.3% and total sperm defects (DTotal) of 72.5 ± 34.3 %. It was observed a high and positive correlation between age at puberty (IDPUB), body weight (0.63), IDPUB and PE (0.45), due to the fact that the animals were sexually late. At the age range studied, there was a high correlation between PE and body weight, DM and DTOTAL, and medium to low magnitude with the physical aspects of the semen (MOT, VIG and CONC). Thus, the PE can be used in young animals, as selection criteria for sexual precocity. / O objetivo com o presente trabalho foi verificar se as biotecnologias de reprodução assistida Fertilização in vitro (FIV) e Inseminação Artificial (IA) podem interferir nos processos de puberdade de tourinhos, em comparação aos produtos gerados por monta natural, bem como mensurar os parâmetros biométricos e seminais destes animais, obtidos por diferentes técnicas aplicadas à reprodução animal. Foram realizadas nove coletas de dados, utilizando 189 animais da raça Gir, com idades variando entre um dia de vida a 24 meses. Estes animais foram classificados em três categorias, de acordo com a técnica reprodutiva através da qual foram gerados, sendo os grupos 1, 2 e 3 constituídos pelos animais gerados, respectivamente, por FIV (61 animais), IA (106 animais) e por monta natural (22 animais). Os animais foram criados em sistema a pasto com suplementação concentrada e desmamados por volta dos 12 meses de idade. A puberdade foi determinada por meio das características físicas e morfológicas do sêmen. Não houve diferença significativa entre os três grupos avaliados em relação à idade, características ponderais e biometria testicular por ocasião da idade à puberdade, demonstrando que o tipo de biotecnologia empregado na produção animal não interferiu no desenvolvimento ponderal e reprodutivo dos mesmos. Os tourinhos alcançaram a puberdade aos 19,0 ± 2,8 meses, pesando 264,0 ± 46,0 Kg e com 27,4 ± 3,4 cm de perímetro escrotal (PE), demonstrando ser sexualmente tardios. Nessa ocasião, os grupos de animais apresentaram valores médios e respectivos desvios-padrão de 1,8 ± 1,0 ml de volume do ejaculado (VOL), turbilhonamento (TURB) de 0,9 ± 1,0 (0-5), motilidade espermática progressiva (MOT) de 52,3 ± 22,8%, vigor (VIG) de 2,6 ± 0,6 (0-5), concentração espermática no ejaculado (CONC) de 647,8 ± 858,6 (x106 espermatozóides), defeitos espermáticos maiores (DM) de 58,9 ± 31,5%, defeitos espermáticos menores (Dmen) de 13,6 ± 8,3% e defeitos espermáticos totais (DTotal) de 72,5 ± 34,3%. Foi observada correlação alta e positiva entre idade à puberdade (IDPUB) e peso corporal (0,63) e IDPUB e PE (0,45), devido ao fato dos animais serem sexualmente tardios. Na faixa etária avaliada, verificou-se correlação alta do PE com peso corporal, DM e DTOTAL e de média a baixa magnitude com os aspectos físicos do sêmen (MOT, VIG e CONC). Desta forma, o PE pode ser utilizado, em animais jovens, como critério de seleção para precocidade sexual.

<p>Pojave ekstremnih padavina dovode do stvaranja vi&scaron;ka vode koji utiče na odvijanje stabilne poljoprivredne proizvodnje, ali i na životnu sredinu, ekonomiju i dru&scaron;tvo u celini. Uvođenjem biotehničkih mera u melioracionu praksu, kao dopunske mere na sistemima za odvodnjavanje, posledice prevlaživanja zemlji&scaron;ta mogle bi biti značajno umanjene. Sagledavanjem vremenske i prostorne pojave vi&scaron;ka vode na sistemima za odvodnjavanje primena biotehničkih mera može služiti, pored primarnog cilja, za postizanje povećanja efikasnosti sistema za odvodnjavanje, stabilizaciju obala, pobolj&scaron;anje kvaliteta vode u vodotocima, zatim za ostvarivanje optimalne &scaron;umovitosti, povećanje i stabilizaciju prinosa poljoprivrednih kultura, kao i povećanje biodiverziteta.<br />U radu primenjena je metodologija na osnovu koje je prikazano kako biotehničke mere mogu povećati efikasnost sistema za odvodnjavanje kroz smanjenje vremena potrebnog za evakuaciju sakupljenih i dovedenih vi&scaron;kova vode. Postupak određivanja povećanja efikasnosti podrazumeva odeđene korake. Prvi korak zasniva se na određivanju ključnih kriterijuma koji utiču na odabir lokaliteta za primenu biotehničkih mera. Da bi se dobili pouzdani i realni podaci potrebno je isključivanje subjektivnih ocena. To je postignuto primenom entropije odnosno objektivne metode za određivanje težinskih koeficijenata na osnovu kojih su kriterijumi za odabir pogodnosti lokaliteta izračunati. Sledeći korak podrazumeva određivanje vremena odvodnjavanja na osnovu merodavnih vi&scaron;kova vode koji se formiraju na sistemima pri različitim povratnim periodima. Poslednji korak odnosi se pre svega na zasnivanje biotehničkih mera na osnovu kojih se stvaraju uslovi za povećanje efikasnosti sistema za odvodnjavanje. Rezultati pogodnosti lokaliteta za primenu biotehničkih mera, vreme odvodnjavanja, kao i povećanje efikasnosti svih sistema za odvodnjavanje na teritoriji Vojvodine, izraženo kroz smanjenje potrebnog vremena odvodnjavanja, prikazani su kori&scaron;ćenjem geografsko informacionog sistema u vidu karata.<br />Primenom biotehničkih mera sprovodi multidisciplinaran pristup koji teži da zadovolji zainteresovane strane koje su u teoriji komplementarne, ali u realnosti obično u konfliktu. Dono&scaron;enje odluka gde, kakve i koji obim ovih mera primeniti trebalo bi da bude, od globalnog do lokalnog pristupa, &scaron;to stručnije bez ili sa minimalnim uticajem subjektivnih ocena, kao i sveobuhvatno i objektivno sagledavanje konkretnih i specifičnih problema koji vladaju na svakom sistemu za odvodnjavanje. Iako imaju mane, prednost uvođenja ovih mera ogleda se kroz jednostavnost primene u praksi u okvirima postojeće zakonske regulative, a na osnovu načela integralnosti, prevencije i predostrožnosti, očuvanja prirodnih resursa, održivog razvoja i primene podsticajnih mera.</p> / <p>Occasional extreme rainfall leads to the accumulation of excessive amount of water, which affects the course of the stable agricultural production, as well as the environment, economy and the society as a whole. Introducing biotechnical measures into the land reclamation procedure, as an additional measure in drainage systems, could significantly reduce the consequences of waterlogging. By perceiving the temporal and spatial appearance of excessive amount of water in drainage systems, the application of the biotechnical measures could, in addition to its primary goal, help achieve increased efficiency of drainage systems, stabilization of banks, improved water quality in watercourses, but also in achieving optimal density of area under forests, increase and stabilization of the agricultural crops&#39; yield, as well as increased biodiversity.<br />The methodology applied in this paper, based on which it was displayed how biotechnical measures could increase the efficiency of the drainage systems through reduction of the time needed for the evacuation of collected and imported excessive amount of water. Defining the procedure of efficiency increase includes certain steps. The first step is based on defining key criteria that influence the choice of locality for the biotechnical measures application. In order to obtain reliable and accurate data it is necessary to exclude subjective estimations. That is achieved with the application of the Entropy, an objective method for defining weight coefficients based on which the criteria for determining the suitability of the locality are calculated. Next step is defining the drainage time based on design excessive amount of water formed in systems with different return periods. The last step refers primarily on establishing biotechnical measures on the basis of which the conditions are created for increasing drainage systems&#39; efficiency. The results of suitability of the locality for the application of biotechnical measures, the time of drainage, as well the increase the efficiency of all the drainage systems on the territory of Vojvodina, expressed through the reduction of the necessary drainage time, are shown using Geographical Information System in forms of maps.<br />Application of biotechnical measures means implementing a multidisciplinary approach that strives to please interested parties which are complementary in theory, but in reality are usually conflicted. Deciding where, what kind and in which extend to apply these measures, from global to local approach, should be as professional as possible, without or with the minimal influence of subjective estimations, as well as comprehensive and objective overview of specific and particular problems that command over every draining system. Even though they have certain flaws, the advantage of introducing these measures is reflected in simplicity of practical application within the frame of existing legal regulation, and based on the principle of integrity, prevention and precaution, conservation of natural resources, sustainable development and implementation of incentive measures.</p>

Master thesis aims to assessment of abrasion on banks of valley reservoir Brno. There was photodocumentation done and current conditions of abraded banks assessed during field survey. There was variables required to detect bottom of brasion cliff and maximal teoretical shift of bank line in the solved location calculated. There was suggested totaly nine types of precaution against other shift of bank line in cross-sections of abraded banks.

The aim of this project is design front breakwaters on the valley dam Brno, area Osada. These precautionaries must obviate another destruction of soil on coast, abrasion. The correct design is depending on a definition of abrasion terminant AT, it is point where regress of bank stops. We need elaborate counts of water levels in the dam for last ten years, for the definition of that abrasion point. After that follows definition of the most-count water level Mnmax and definition of a ground elevation bottom of the most highly abrasion crib Va.