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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

An integrated soil conservation program and its impact on the annual soil loss of the Dumpul (Indonesia) subwatershed

Siswomartono, Dwiatmo. January 1982 (has links) (PDF)
Thesis (M.S. - Soils, Water and Engineering)--University of Arizona, 1982. / Bibliography: leaves 81-83.
2

Avaliação do potencial de produção de sedimento na sub bacia hidrográfica do rio Pirajibu-Mirim /

Bochichi, Diego da Cruz. January 2018 (has links)
Orientador: Antonio Cesar Germano Martins / Banca: Roberto Wagner Lourenço / Banca: Darllan Collins da Cunha e Silva / Resumo: A perda de solos em bacias hidrográficas pode causar prejuízos ambientais e comprometer os usos múltiplos potenciais desta bacia. Ações como desmatamento, atividades agrícolas, entre outras, expõem o solo aos agentes naturais (precipitação, vento) e estes desprendem e carreiam o solo para as porções mais baixas na bacia, promovendo o assoreamento dos corpos d'água. Estudos sobre o tema são importantes para auxiliar na gestão, manejo e entendimento destes ambientes e mitigação do fenômeno. Neste sentido, este trabalho tem como objetivo estimar a perda de solo na sub-bacia do Pirajibu-Mirim. Para isto, foram utilizadas ferramentas de análise de imagens e de dados da bacia para calcular a Equação Universal da Perda de Solos (EUPS) definida por Wischmeier & Smith (1978). A sub-bacia está inserida no município de Sorocaba-SP e tem uma área de aproximadamente 54 km². Para compor a equação, todas as variáveis foram levantadas separadamente para então calcular a EUPS em ambiente SIG para os anos de 2000 a 2016. Os resultados indicaram que os anos de 2003 e 2012 apresentaram os maiores valores de perdas de solo acima de 200 ton/ha.ano e em 2013 os menores valores de perdas de solo acima de 200 ton/ha.ano. Outra informação importante foi que no período estudado, aproximadamente 50% da área tem perdas de solo abaixo de 15 ton/ha.ano, indicando boa preservação do solo. / Abstract: The loss of soil in watershed can cause environmental damage and compromise the multiple potential uses of this watershed. Action as deforestation, agricultural activities, among others, expose the soil to natural agents (precipitation, wind) that causes the release of these soils to lower portion of watershed, promoting silting of the water bodies. Studies about the theme are important to improve the management and understanding of these environments and phenomenon mitigation of silting. Therefore, this work had as aim the estimation of soil loss in sub basin Pirajibu-Mirim. For this, tools of image and data analysis were used to estimate the Universal Soil Loss Equation (USLE) defined by Wischmeier & Smith (1978). The sub basin is inserted in Sorocaba city, São Paulo state and has an area 54km². To compose the equation, the variables were obtained separately and then the USLE was calculated from 2000 to 2016. The results indicated that the years 2003 and 2012 demonstrated the highest values of soil loss above 200 ton/ha.a and 2013 the lowest value of soil loss above 200 ton/ha.a. Other important information is that in studied period, almost 50% of the area had soil lower than 15 ton/ha.a, indicating satisfactory soil preservation. / Mestre
3

Evaluation of the universal soil loss equation on a selected reclaimed eastern surface mine area

Hockman, Edwin Leon January 1981 (has links)
Fifteen field plots were installed on a "Mountain Top Removal" type of surface mine near Beckley, West Virginia to evaluate the the predictability of the Universal Soil Loss Equation for a selected eastern surface mine spoil. Comparison of predicted and measured soil losses indicated significant error. For slopes greater than 20% the equation overpredicted for all predictions. Predictions for erosion losses greater than three tons/acre were significantly more accurate than those for losses less than 3 tons/acre. Comparison of soil characteristics of unmined and reclaimed areas indicated the reclaimed areas had significantly greater amounts of clay and silt present, and had greater bulk density. The reclaimed areas also had significantly lower infiltration rates, organic matter, very-fine sand and total sand. The erodibility factor, K, was also greater for the reclaimed area than for the unmined area. / Master of Science
4

A study of the practicability of the photometer method in making soil loss measurements

Fleshman, William Turner 07 July 2010 (has links)
The following conclusions may be drawn from this investigation: (1) The photometer is an accurate and dependable device for measuring light absorption by turbid soil and water solutions when the soil particles are of nearly constant size. The tests made with the soil that had passed through a 100-mess sieve proved this fact, also, the tests made with the composite soil gave vary accurate results. (2) the composite runoff soil samples from the three slopes must have contained particles of approximately the same size. This is shown by the accuracy of the results obtained with this soil. / Master of Science
5

Approximating Soil Loss Calculations with Satellite Data and Multivariate Regression Analyses

Marr, Paul Gerard 12 1900 (has links)
Digital satellite remote sensing and Geographic Information Systems (GIS) have been used effectively to determine the Universal Soil Loss Equation (USLE) output for a number of North Texas watersheds. This method involves determining the values of each of the USLE factors and using these factors as information layers within the GIS.
6

Estudo da vulnerabilidade à erosão com a aplicação da Equação Universal de Perda de Solo na alta bacia hidrográfica do rio Jacaré Pepira, utilizando SIG/SPRING /

Costa, Ana Lúcia Carneiro da. January 2005 (has links)
Orientador: Carlos de Almeida Nóbrega / Banca: Luiz Roberto Cottas / Banca: Henry Lesjak Martos / Resumo: A expansão territorial do agronegócio e da área urbana na Alta Bacia Hidrográfica do Rio Jacaré Pepira impacta a preservação de seus recursos naturais. A erosão se destaca como um processo do meio físico que possui uma relação estreita com o uso do solo. Para estudo da vulnerabilidade à erosão realizou-se uma análise segmentada dos fatores naturais e antrópicos, apoiando-se no modelo matemático da Equação Universal de Perda de Solo (EUPS). O meio físico foi compartimentado nas sub-bacias que estão parcial ou totalmente inseridas na Área de Proteção Ambiental (APA) de Corumbataí. As sub-bacias foram consideradas como unidades de análise, com a medição de parâmetros morfométricos. Para estudo dos fatores antrópicos, realizou-se levantamentos de campo para caracterização do uso e manejo do solo praticado nas principais explorações agropecuárias com a identificação de feições erosivas lineares. As informações de ocupação do solo foram extraídas da classificação automática de imagens de satélite dos anos de 1988 (TM/Landsat) e 2004 (CBERS) com controle de campo. O trabalho apresentou como resultado o zoneamento da área quanto à susceptibilidade natural, vulnerabilidade e adequação ao uso do solo. As informações integradas em um banco de dados em SIG/SPRING permitem fornecer instrumentos para trabalhos de gerenciamento ambiental. / Abstract: Territorial expansion of agrobusiness and urban areas in the Jacaré Pepira River watershed impact its natural resources. Erosion stands out as a physical environment process that has a close relationship with land use. The study of erosion vulnerability was accomplished on a natural and human factors segmented analysis, based on Universal Soil Loss Equation (USLE) model. Physical environmental was shared on the sub-basin belong to APA de Corumbataí (Corumbataí Environmental Protection Area). Sub-basins were considered as units of analysis, witch the morfometric parameters measurements. Field work was used on human factor study, aiming the management characterization for main crops, including the identify of areas affected by gullies. Data about land use were obtained by automatic classification of 1988 (TM/Landsat) and 2004 (CBERS) satellite images with field control. Zoning of the area was accomplished based on natural erosion potential (PNE), erosion vulnerability and wishing land use. Data input to a GIS/SPRING database can provide tools for environmental management. / Mestre
7

Evaluation of the USLE (Universal Soil Loss Equation) to estimate soil loss from hobby farms and commercial pastoral properties around Murrumbateman, NSW, Australia

Son, Vo Thanh, n/a January 1993 (has links)
This thesis is an evaluation of the use the USLE to estimate soil loss from two pastoral land uses - commercial properties and "hobby farms" in Murrumbateman. Sensitivity analysis was used to evaluate the USLE components. Sediment measurement in farm dams was taken to estimate sediment yield from several sites, as an alternative approach to study soil loss. The annual soil loss from entire study area was 0.25 t/ha/year whilst these figures from commercial properties and hobby farms were 0.29 t/ha/year and 0.21 t/ha/year, respectively. The annual average sediment yield from three catchments in hobby farms was 0.3 t/ha/year. The USLE was found to be highly sensitive to slope steepness, ground cover and stocking rates. The critical values were 16% for slopes, 35% for the ground cover and 19 Dry Sheep Equivalent/ha for stocking rate. I tentatively conclude that the USLE is sufficiently sensitive to detect differences in soil loss between the two land uses. There is, however, a need to improve the operation of the model in some respects. The use of farm dams for estimating sediment yield also shows promise.
8

Estudo da vulnerabilidade à erosão com a aplicação da Equação Universal de Perda de Solo na alta bacia hidrográfica do rio Jacaré Pepira, utilizando SIG/SPRING

Costa, Ana Lúcia Carneiro da [UNESP] 11 November 2005 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:26:11Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-11-11Bitstream added on 2014-06-13T19:13:07Z : No. of bitstreams: 1 costa_alc_me_rcla.pdf: 2147425 bytes, checksum: 989559e2911176da648ab906f9e027e0 (MD5) / A expansão territorial do agronegócio e da área urbana na Alta Bacia Hidrográfica do Rio Jacaré Pepira impacta a preservação de seus recursos naturais. A erosão se destaca como um processo do meio físico que possui uma relação estreita com o uso do solo. Para estudo da vulnerabilidade à erosão realizou-se uma análise segmentada dos fatores naturais e antrópicos, apoiando-se no modelo matemático da Equação Universal de Perda de Solo (EUPS). O meio físico foi compartimentado nas sub-bacias que estão parcial ou totalmente inseridas na Área de Proteção Ambiental (APA) de Corumbataí. As sub-bacias foram consideradas como unidades de análise, com a medição de parâmetros morfométricos. Para estudo dos fatores antrópicos, realizou-se levantamentos de campo para caracterização do uso e manejo do solo praticado nas principais explorações agropecuárias com a identificação de feições erosivas lineares. As informações de ocupação do solo foram extraídas da classificação automática de imagens de satélite dos anos de 1988 (TM/Landsat) e 2004 (CBERS) com controle de campo. O trabalho apresentou como resultado o zoneamento da área quanto à susceptibilidade natural, vulnerabilidade e adequação ao uso do solo. As informações integradas em um banco de dados em SIG/SPRING permitem fornecer instrumentos para trabalhos de gerenciamento ambiental. / Territorial expansion of agrobusiness and urban areas in the Jacaré Pepira River watershed impact its natural resources. Erosion stands out as a physical environment process that has a close relationship with land use. The study of erosion vulnerability was accomplished on a natural and human factors segmented analysis, based on Universal Soil Loss Equation (USLE) model. Physical environmental was shared on the sub-basin belong to APA de Corumbataí (Corumbataí Environmental Protection Area). Sub-basins were considered as units of analysis, witch the morfometric parameters measurements. Field work was used on human factor study, aiming the management characterization for main crops, including the identify of areas affected by gullies. Data about land use were obtained by automatic classification of 1988 (TM/Landsat) and 2004 (CBERS) satellite images with field control. Zoning of the area was accomplished based on natural erosion potential (PNE), erosion vulnerability and wishing land use. Data input to a GIS/SPRING database can provide tools for environmental management.
9

Řešení protierozní ochrany na modelovém povodí - Malče Budský potok. / Solution of soil protection from erosion in model catchment - Malče Budský stream.

RADA, Václav January 2009 (has links)
The aim of this thesis is to assess and evaluate the erosion phenomena at the model catchment of Malče Budský stream. This site is located on the cadastral areas Besednice, Soběnov and Malče. This survey was conducted in aspects of pedology, hydrogeology and climate. Further evaluations were rain amount for the nearest meteorological station, which is located in Soběnov. To evaluate and calculate erosion parameters for a given locality the methods of universal soil loss equation by Wishmeier and Smith and modified universal soil loss equation by Williams and Berndt have been used. The CN method was used for calculations and following evaluation of soil loss. The result of this thesis is designing, generalization and refinement of individual factors in solved area.
10

Εκτίμηση μοντέλου διάβρωσης και στερεοπαροχής στον ταμιευτήρα του φράγματος Πηνειού νομού Ηλείας

Βιδάλη, Μαρία 11 October 2013 (has links)
Είναι ευρέως γνωστό ότι οι διαδικασίες της διάβρωσης του εδάφους επηρεάζονται από ένα πλήθος βιοφυσικών και ανθρώπινων παραγόντων και εμφανίζονται με διαφορετικές εντάσεις σε διαφορετικά περιβάλλοντα. Εντούτοις, οι χωρικές και χρονικές κλίμακες των διαδικασιών είναι ακόμα ανεπαρκώς κατανοητές. Ως εκ τούτου, ο έλεγχος και ο υπολογισμός της διάβρωσης και της απόθεσης αποτελεί ένα σύνθετο και δύσκολο στόχο. Επομένως, είναι ανάγκη να βελτιωθεί η κατανόηση των διαδικασιών λαμβάνοντας υπόψη την ποσοτική τους έκφραση, ώστε να είναι σε θέση ειδικοί επιστήμονες να αναλύσουν το αντίκτυπο του φαινομένου αυτού. Αντικείμενο της παρούσας μεταπτυχιακής διατριβής είναι η εκτίμηση μοντέλου διάβρωσης και στερεοπαροχής στον ταμιευτήρα του ομώνυμου φράγματος του ποταμού Πηνειού, στην περιοχή του Νομού Ηλείας. Απώτερος στόχος αυτής της μελέτης είναι ο υπολογισμός και η εκτίμηση του όγκου των φερτών υλών που έχουν αποτεθεί στον ταμιευτήρα του φράγματος, με αποτέλεσμα την πολυετή δυσλειτουργία του, με σκοπό την εφαρμογή πρακτικών που θα δώσουν παράταση στην οικονομική ζωή του έργου. Προς την κατεύθυνση αυτή αναπτύχθηκε μια μέθοδος η οποία συνδυάζει την Παγκόσμια Εξίσωση Εδαφικής Απώλειας (Universal Soil Loss Equation - USLE) με τα Γεωγραφικά Συστήματα Πληροφορίας (GIS), συγκεκριμένα το λογισμικό ArcGIS 10. Η USLE υπολογίζει την μακροπρόθεσμη μέση ετήσια απώλεια εδάφους πολλαπλασιάζοντας πέντε συγκεκριμένους παράγοντες που περιγράφουν τα χαρακτηριστικά λεκανών, όπως η διαβρωτικότητα της βροχόπτωσης, η διαβρωσιμότητα του εδάφους, η μορφολογία του εδάφους, η φυτοκάλυψη του εδάφους και η διαχείριση των εδαφών κατά της διάβρωσης. Το GIS χρησιμοποιείται για την αποθήκευση των συντελεστών της USLE ως μεμονωμένα ψηφιακά επίπεδα τα οποία πολλαπλασιάζονται μεταξύ τους για να δημιουργήσουν έναν δυναμικό χάρτη εδαφικής διάβρωσης. Αυτός ο συνδυασμός παρέχει έναν τρόπο εκτίμησης της πιθανής διάβρωσης του εδάφους σε μια περιοχή με τις υπάρχουσες πηγές δεδομένων. Ο εντοπισμός των περιοχών που παρουσιάζουν μεγαλύτερο κίνδυνο διάβρωσης και η χαρτογράφησή τους, συμβάλουν στην πρόληψη της περαιτέρω υποβάθμισης του εδάφους με χρήση των απαραίτητων αντιδιαβρωτικών μέτρων. Για τον υπολογισμό του συντελεστή διαβρωτικότητας της βροχόπτωσης (R) και για την εξαγωγή του χάρτη κατανομής της χρησιμοποιήθηκαν οι μηνιαίες και ετήσιες μετρήσεις βροχόπτωσης από πέντε μετεωρολογικούς σταθμούς που εντοπίζονται στην λεκάνη απορροής ανάντη του φράγματος. Ο συντελεστής διαβρωσιμότητας του εδάφους (Κ) απαιτεί μετρήσεις πεδίου για την εκτίμηση των ιδιοτήτων του εδάφους. Στην παρούσα μελέτη, λόγω αδυναμίας συγκέντρωσης δειγμάτων, οι ιδιότητες του εδάφους εκτιμήθηκαν με γεωλογικά κριτήρια και εν συνεχεία με τη χρήση του GIS δημιουργήθηκε χάρτης κατανομής διαβρωσιμότητας του εδάφους. Με βάση το Ψηφιακό Μοντέλο Αναγλύφου της περιοχής μελέτης υπολογίστηκε ο τοπογραφικός συντελεστής (LS), ενώ βάσει του CORINE και σύμφωνα με τη βιβλιογραφία υπολογίστηκε ο παράγοντας κάλυψης και διαχείρισης γης (C). Τέλος, ο συντελεστής διαχείρισης των εδαφών κατά της διάβρωσης (P) ορίστηκε ίσος με τη μονάδα (1) καθώς δεν έχει παρθεί κανένα μέτρο για την προστασία των εδαφών κατά της διάβρωσης σε όλη την λεκάνη απορροής. Βάσει των παραπάνω υπολογισμών προέκυψε η μέση ετήσια απώλεια εδάφους ανά μονάδα επιφάνειας της λεκάνης απορροής ανάντη του φράγματος, η οποία ανέρχεται στους ----- t/ha ή SE=---- t/km2. Κατόπιν υπολογισμού της μέσης ετήσιας εδαφικής διάβρωσης, βάσει εμπειρικής μεθόδου υπολογίστηκε ο συντελεστής (%) στερεοαπορροής και κατ' επέκταση η μέση ετήσια στερεοαπορροή της λεκάνης ανάντη του φράγματος Πηνειού, η οποία ανέρχεται σε ----- t/ha ή ----- t/km2. Για την συγκεκριμένη λεκάνη απορροής το ----- των παραγόμενων φερτών υλών είναι αυτό που τελικά μεταφέρεται και αποτίθεται κάθε χρόνο στον ταμιευτήρα του φράγματος, τα οποία ανέρχονται σε ------ t. / It’s widely known that the procedures of soil erosion are affected by a number of biophysical and human factors and appeared with different intensities in different places. However, the spatial and temporal scales of the procedures are still poorly understood. Therefore, the control and the calculation of soil erosion and deposition are a complex and difficult task. So, it’s necessary to improve the understanding of the procedures, taking into account their quantitative expression, in order to scientists be able to analyze the impacts of this phenomenon. The main purpose of this thesis is the estimation of the erosion and sediment model in the reservoir of the homonymous dam of river Peneus, in the prefecture of Ilia. The ultimate goal of this study is to calculate and estimate the volume of sediment that have been deposited in the reservoir of the dam, resulting in perennial dysfunction , in order to implement practices that will give extension in the economic life of the project. For this propose a method has been developed that combines the Universal Soil Loss Equation- USLE with Geographic Information Systems- GIS. This method is the software ArcGIS 10. The USLE equation calculates the long-term average annual soil loss by multiplying five specific factors that describe the characteristics of the basins, such as the rainfall erosivity, the soil erodibility, the topography, the vegetation cover of the soil and the management of soil erosion. The GIS system is used to store the USLE’s factors as individual digital levels that are multiplied together to create a dynamic map of soil erosion. This combination provides a way of estimating of the possible erosion of the soil in an area with the existing data sources. The identification of the areas of greatest risk of erosion and their cartography, helped to prevent further soil degradation by using the necessary corrosion measures. For calculating the rainfall erosivity factor (R) and for the extraction of the distribution map of erosion are used monthly and annual rainfall measurements from five meteorological stations located in the watershed upstream of the dam. The soil erodibility factor (K) requires field measurements to estimate the properties of the soil. In this study, due to our inability to obtain samples, soil properties were evaluated with geological criteria and subsequently using the GIS created map distribution of soil erodibility. Based on the digital elevation model of the study area, was calculated the topographic factor (LS), while under CORINE and the literature was calculated the capper and land administration (C). Finally, the factor of soil management against erosion (P) was set equal to one (1) as there has not been taken any step to protect soils against erosion throughout the basin. Based on the above calculation showed average annual soil loss per unit area of the watershed upstream of the dam, which amounts to ---- t/ha or SE=---- t/km2. After calculation the average annual soil erosion, based on the empirical method has calculated the sediment delivery ratio and thus the average annual sediment yield of the watershed upstream of the dam Peneus, which is -----t/ha or ----- t/km2. For this specific watershed the ----% of the produced sediment is what ultimately transported and deposited annually in the reservoir of the dam, which amount to ---- t.

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