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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.
321

Zwischen Nord und Süd, heute und morgen: Welche Beiträge leistet das internationale Waldregime zum Abbau von Ungleichheiten? / Between North and South, today and tomorrow: Does the international forest regime contribute to reducing imbalance?

Weber, Norbert, Pretzsch, Jürgen 11 November 2008 (has links) (PDF)
Das internationale Waldregime kann als Summe von Prinzipien, Normen, Prozeduren und Programmen verstanden werden, welche den Schutz und die Nutzung von Wäldern sowie die Rolle der einzelnen Akteure hierbei regeln sollen. Als Ergebnis des Erdgipfels von Rio 1992 wurden vielfältige Forderungen und Vorschläge für den Abbau von intragenerationalen (Stichwort Nord-Süd-Konflikt) und intergenerationalen Ungleichheiten erhoben. Die Erkenntnisse aus Fallstudien in mehreren asiatischen Ländern (Bangladesh, China, Indien, Nepal) deuten jedoch darauf hin, dass diese Ansätze oft nur wenig zur Lösung von Nutzungskonflikten um Waldressourcen auf der lokalen Ebene beitragen können. Gerade hier muss aber angesetzt werden, um Veränderungen im Hinblick auf die Stabilisierung des globalen Klimas herbeizuführen. / The international forest regime is characterised by principles, norms, procedures and programs, which follow the target to regulate forest conservation and use as well as to determine the role of involved actors. In the conclusions of the Rio-process many proposals with focus on the reduction of the intergenerational and intragenerational imbalances have been made. Case studies from some Asiatic countries (Bangladesh, China, India, Nepal, Vietnam) indicate, that the above mentioned global regulations hardly respond to questions of land use and forest use on a local level. Urgent actions and interventions are necessary on this local level to stabilise the global climate.
322

Herstellung eines Satellitenbildmosaiks von Palpa/Peru mit Daten des Satelliten QuickBird

Eifrig, Sven 11 October 2007 (has links) (PDF)
Die vorliegende Arbeit beschreibt die Herstellung eines Satellitenbildmosaiks von Palpa (Peru) mit Daten des Satelliten QuickBird. Die zur Verfügung gestellten Kartenmaterialien werden hinsichtlich ihrer Genauigkeit untersucht. Die Arbeit beschäftigt sich weiterhin mit dem zur Verfügung gestellten digitalen Geländemodell (SRTM-Daten). Als Ergebnis wird ein umfangreiches Kartenmaterial präsentiert, welches zur GPS Messgrundlage in Palpa dienen soll.
323

Kennwert-Schätzung aus Georadar-Transmissionsdaten

Parnadi, Wahyudi Widyatmoko 25 November 2009 (has links) (PDF)
Neben der Ausbreitungsgeschwindigkeit ist die Absorption elektromagnetischer Wellen der wichtigste Parameter für die Bearbeitung und Interpretation von Georadar-Daten. Für die realitätsnahe Beschreibung der Ausbreitung elektromagnetischer Wellen in Gesteinen eignet sich das Modell mit konstantem Q und einem Dispersionsansatz der Phasengeschwindigkeit nach Futterman (1982). Anhand von Modellrechnungen wird die Wirkung dieser Parameter auf Wavelets untersucht. Die Ermittlung des absorptionscharakterisierenden Gütefaktors Q aus GPR-Transmissionsdaten erfolgt auf der Basis einer Erweiterung der Q-Definition. Die dazu benutzte Referenzfrequenz fR ist eine Potenzfunktion von zu vergleichenden Amplitudendichten der entsprechenden Äquivalenzspektren. Die Anwendbarkeit der danach benannten Methode der Äquivalenten Bandbreite wird sowohl an synthetischen Daten als auch an Messergebnissen nachgewiesen, die an einem Sandsteinblock sowie an anstehendem Gneis erhalten worden sind. Es werden Möglichkeiten aufgezeigt, Querbeziehungen zwischen Q-Werten und petrophysikalischen Parametern herzustellen.
324

Sedimentology and reservoir geology of the middle-upper cretaceous strata in unity and heglig fields in SE Muglad Rift Basin, Sudan

Sayed, Ali Mohammed Ibrahim 11 July 2009 (has links) (PDF)
This study investigates the depositional environment, source area, sandstone composition, diagenetic properties, reservoir quality and palaeogeography of the Middle–Upper Cretaceous strata at the Unity and Heglig Fields in the SE Muglad Rift Basin, Sudan. In this study, the subsurface Cretaceous sediments were investigated essentially by seven sedimentological techniques. These included subsurface facies analysis, which was based on 1500 cutting samples and seven conventional cores description as well as on wire line logs and three seismic section analyses, petrographic analyses that included heavy mineral analysis, thin sections and scanning electron microscopic investigations, clay mineral as well as geochemical analyses. The facies description and the analysis of conventional cores from the Bentiu, Aradeiba, and Zarga Formations in the Unity and Heglig Field revealed the presence of nine major lithofacies types, all of them are siliciclastic sediments. They can be interpreted as deposits of fluvial, deltaic and lacustrine environments. Moreover, based on wire line logs, cores and cutting sample descriptions and analyses and also on seismic section analyses, the Middle–Upper Cretaceous strata in Unity and Heglig Fields can be classified into three different units of first-order sequences, i.e. fluvial-dominated unit, lacustrine-dominated unit and deltaic-dominated unit. These depositional units most probably testify to environmental change in response to main tectonic pulses during the Turonian – Late Senonian second rifting phase. The seismic analysis revealed that the maximum thickness of the Cretaceous sediments in the study area reaches about 6000 m in the NW part of the Heglig Field. Moreover, the seismic interpretation has revealed three seismic facies reflection patterns: parallel and subparallel reflection patterns (uniform rates of deposition), divergent reflection pattern (differential subsidence rates) and hummocky clinoform pattern (clinoform lobes of delta). The thin section investigations of the core samples revealed that feldspar accounts for 13.5 – 22 %, that of the quartz and the lithic fragments are ranging between 75.7 – 85.2 % and 0.0 7.3 % respectively. Consequently, the sandstones of the study area are classified as subarkoses. Moreover, the modal analysis of the sandstones revealed, that they stem generally from a continental provenance, transitional between the stable interior of a craton and a basement uplift, which is a basement area of relatively high relief along rifts. This allows the detrital components to be recycled and transported for rather long distances and to be deposited in extensional and pull-apart basins. The reservoir quality of the Bentiu and Aradeiba Formations in general is better than that of the Zarga Formation. The porosity of the Bentiu and Aradeiba Formations ranges between 16.7 – 30.0 % and 18.6 – 25.3 %, respectively, whereas the porosity of the Zarga Formation ranges between 16.3 – 23.7 %. Moreover, the thin section investigations and the scanning electron microscope (SEM) analysis for the sandstones of the study area revealed that their reservoir quality was affected positively and negatively by several diagenetic processes. These processes include: mechanical compaction factors (grain slippage and crushing of the ductile grains), quartz overgrowths, precipitation of siderite and calcite, feldspar and clay mineral authigenesis, dissolution of carbonate and of the labile detrital grains and clay infiltration. Furthermore, the reservoir quality of the study intervals was not only affected by the above mentioned diagenetic processes, but also in a large-scale by the type of depositional environment. The study of the heavy minerals revealed that the amounts of the heavy minerals kyanite and garnet supersede those of zircon, tourmaline and rutile. This indicates a metamorphic source rock of originally granitic and/or granodioritic composition for the sediments of the study area. Three heavy mineral assemblage zones with obvious lateral and vertical continuity were identified: a zircon-rutile zone (ZR), a sillimanite-epidote-hornblende zone (SEH) and a kyanite-staurolite-andalusite-garnet zone (KStAnG). On the basis of the ZTR (zircon-tourmaline-rutile) index as well as on the SEH (sillimanite-epidote-hornblende) index, four major maturation levels were constructed: immature, moderately mature, mature and overmature. The clay mineral analysis allowed the subdivision of the Middle–Upper Cretaceous strata into three to two clay mineral zones, which reflect mainly different environmental and diagenetic conditions. The lower clay mineral zone consists of kaolinite, illite/smectite mixed layer, illite, smectite and chlorite. Whereas, the middle zone consists of kaolinite, smectite, illite/smectite mixed layer, illite and chlorite. The upper zone comprises kaolinite, illite, illite/smectite mixed layer, chlorite and smectite. The lower and the upper clay mineral zones contain higher values of kaolinite in comparison to the middle clay mineral zone, whereas the middle zone contains a higher value of smectite in comparison to the lower and the upper clay mineral zones. The higher amount of the kaolinite in the lower and in the upper zones suggest most probably the intensity of chemical weathering and leaching processes under warm humid climate. The marked presence of smectite in the middle zone suggest that the warm humid climate was interrupted by dry seasons. Moreover, the lower clay mineral zone, which shows an increase of illite, chlorite, mixed layer illite/smectite and a higher illite crystallinity, indicates mixed and transitional influences from environmental/tectonic to burial diagenetic controls. Geochemical investigations revealed preferential enrichment and depletion of certain chemical elements in the lacustrine/fluvial/deltaic environments. For instance, the less mobile elements Ti, Ga, Cr and Zr remained in higher amounts in the proximal facies (i.e. in the fluvial channel bar deposits and in the deltaic mouth bar deposits). In contrast, the more mobile elements Mg, Ca, K and Rb occur in higher concentrations in the distal facies (i.e. in the lacustrine deposits, deltaic distal bar deposits and floodplain sediment).
325

A 3d geoscience information system framework

Apel, Marcus 14 July 2009 (has links) (PDF)
Two-dimensional geographical information systems are extensively used in the geosciences to create and analyse maps. However, these systems are unable to represent the Earth's subsurface in three spatial dimensions. The objective of this thesis is to overcome this deficiency, to provide a general framework for a 3d geoscience information system (GIS), and to contribute to the public discussion about the development of an infrastructure for geological observation data, geomodels, and geoservices. Following the objective, the requirements for a 3d GIS are analysed. According to the requirements, new geologically sensible query functionality for geometrical, topological and geological properties has been developed and the integration of 3d geological modeling and data management system components in a generic framework has been accomplished. The 3d geoscience information system framework presented here is characterized by the following features: - Storage of geological observation data and geomodels in a XML-database server. According to a new data model, geological observation data can be referenced by a set of geomodels. - Functionality for querying observation data and 3d geomodels based on their 3d geometrical, topological, material, and geological properties were developed and implemented as plug-in for a 3d geomodeling user application. - For database queries, the standard XML query language has been extended with 3d spatial operators. The spatial database query operations are computed using a XML application server which has been developed for this specific purpose. This technology allows sophisticated 3d spatial and geological database queries. Using the developed methods, queries can be answered like: "Select all sandstone horizons which are intersected by the set of faults F". This request contains a topological and a geological material parameter. The combination of queries with other GIS methods, like visual and statistical analysis, allows geoscience investigations in a novel 3d GIS environment. More generally, a 3d GIS enables geologists to read and understand a 3d digital geomodel analogously as they read a conventional 2d geological map.
326

Biomass Representation in Synthetic Aperture Radar Interferometry Data Sets

Becek, Kazimierz 19 January 2011 (has links) (PDF)
This work makes an attempt to explain the origin, features and potential applications of the elevation bias of the synthetic aperture radar interferometry (InSAR) datasets over areas covered by vegetation. The rapid development of radar-based remote sensing methods, such as synthetic aperture radar (SAR) and InSAR, has provided an alternative to the photogrammetry and LiDAR for determining the third dimension of topographic surfaces. The InSAR method has proved to be so effective and productive that it allowed, within eleven days of the space shuttle mission, for acquisition of data to develop a three-dimensional model of almost the entire land surface of our planet. This mission is known as the Shuttle Radar Topography Mission (SRTM). Scientists across the geosciences were able to access the great benefits of uniformity, high resolution and the most precise digital elevation model (DEM) of the Earth like never before for their a wide variety of scientific and practical inquiries. Unfortunately, InSAR elevations misrepresent the surface of the Earth in places where there is substantial vegetation cover. This is a systematic error of unknown, yet limited (by the vertical extension of vegetation) magnitude. Up to now, only a limited number of attempts to model this error source have been made. However, none offer a robust remedy, but rather partial or case-based solutions. More work in this area of research is needed as the number of airborne and space-based InSAR elevation models has been steadily increasing over the last few years, despite strong competition from LiDAR and optical methods. From another perspective, however, this elevation bias, termed here as the “biomass impenetrability”, creates a great opportunity to learn about the biomass. This may be achieved due to the fact that the impenetrability can be considered a collective response to a few factors originating in 3D space that encompass the outermost boundaries of vegetation. The biomass, presence in InSAR datasets or simply the biomass impenetrability, is the focus of this research. The report, presented in a sequence of sections, gradually introduces terminology, physical and mathematical fundamentals commonly used in describing the propagation of electromagnetic waves, including the Maxwell equations. The synthetic aperture radar (SAR) and InSAR as active remote sensing methods are summarised. In subsequent steps, the major InSAR data sources and data acquisition systems, past and present, are outlined. Various examples of the InSAR datasets, including the SRTM C- and X-band elevation products and INTERMAP Inc. IFSAR digital terrain/surface models (DTM/DSM), representing diverse test sites in the world are used to demonstrate the presence and/or magnitude of the biomass impenetrability in the context of different types of vegetation – usually forest. Also, results of investigations carried out by selected researchers on the elevation bias in InSAR datasets and their attempts at mathematical modelling are reviewed. In recent years, a few researchers have suggested that the magnitude of the biomass impenetrability is linked to gaps in the vegetation cover. Based on these hints, a mathematical model of the tree and the forest has been developed. Three types of gaps were identified; gaps in the landscape-scale forest areas (Type 1), e.g. forest fire scares and logging areas; a gap between three trees forming a triangle (Type 2), e.g. depending on the shape of tree crowns; and gaps within a tree itself (Type 3). Experiments have demonstrated that Type 1 gaps follow the power-law density distribution function. One of the most useful features of the power-law distributed phenomena is their scale-independent property. This property was also used to model Type 3 gaps (within the tree crown) by assuming that these gaps follow the same distribution as the Type 1 gaps. A hypothesis was formulated regarding the penetration depth of the radar waves within the canopy. It claims that the depth of penetration is simply related to the quantisation level of the radar backscattered signal. A higher level of bits per pixels allows for capturing weaker signals arriving from the lower levels of the tree crown. Assuming certain generic and simplified shapes of tree crowns including cone, paraboloid, sphere and spherical cap, it was possible to model analytically Type 2 gaps. The Monte Carlo simulation method was used to investigate relationships between the impenetrability and various configurations of a modelled forest. One of the most important findings is that impenetrability is largely explainable by the gaps between trees. A much less important role is played by the penetrability into the crown cover. Another important finding is that the impenetrability strongly correlates with the vegetation density. Using this feature, a method for vegetation density mapping called the mean maximum impenetrability (MMI) method is proposed. Unlike the traditional methods of forest inventories, the MMI method allows for a much more realistic inventory of vegetation cover, because it is able to capture an in situ or current situation on the ground, but not for areas that are nominally classified as a “forest-to-be”. The MMI method also allows for the mapping of landscape variation in the forest or vegetation density, which is a novel and exciting feature of the new 3D remote sensing (3DRS) technique. Besides the inventory-type applications, the MMI method can be used as a forest change detection method. For maximum effectiveness of the MMI method, an object-based change detection approach is preferred. A minimum requirement for the MMI method is a time-lapsed reference dataset in the form, for example, of an existing forest map of the area of interest, or a vegetation density map prepared using InSAR datasets. Preliminary tests aimed at finding a degree of correlation between the impenetrability and other types of passive and active remote sensing data sources, including TerraSAR-X, NDVI and PALSAR, proved that the method most sensitive to vegetation density was the Japanese PALSAR - L-band SAR system. Unfortunately, PALSAR backscattered signals become very noisy for impenetrability below 15 m. This means that PALSAR has severe limitations for low loadings of the biomass per unit area. The proposed applications of the InSAR data will remain indispensable wherever cloud cover obscures the sky in a persistent manner, which makes suitable optical data acquisition extremely time-consuming or nearly impossible. A limitation of the MMI method is due to the fact that the impenetrability is calculated using a reference DTM, which must be available beforehand. In many countries around the world, appropriate quality DTMs are still unavailable. A possible solution to this obstacle is to use a DEM that was derived using P-band InSAR elevations or LiDAR. It must be noted, however, that in many cases, two InSAR datasets separated by time of the same area are sufficient for forest change detection or similar applications.
327

Gated communities in Argentinien - eine Analyse abseits der Megacity Buenos Aires

Lips, Susanne 07 May 2015 (has links) (PDF)
gated communities in Argentinien
328

Erdbebenbeobachtung im Freistaat Sachsen : Dreijahresbericht ...

22 July 2014 (has links)
No description available.
329

Erdbebenbeobachtung im Freistaat Sachsen : Dreijahresbericht

22 July 2014 (has links) (PDF)
In Sachsen liegt der Schwerpunkt der seismischen Aktivität im westsächsisch-ostthüringischen Raum. Ausgehend vom Vogtland verläuft die erdbebengefährdete Zone über das Gebiet von Zwickau und Gera-Ronneburg bis in den Raum von Leipzig. Die Broschüre fasst die Ergebnisse der Erdbebenbeobachtung in Sachsen bzw. Mitteldeutschland im Zeitraum 2010-2012 zusammen und berichtet über die Arbeit des Seismologie-Verbundes. Dargestellt wird auch der Erdbebenschwarm im August/September 2012. Weitere Schwerpunkte bilden die Beschreibung der seismologischen Netze (SXNET und TSN) in Mitteldeutschland und ein Überblick über die Untersuchungen auf dem Gebiet der Seismohydrologie zur Erdbebenprognose im Vogtland.
330

Die Forschungsbohrungen Baruth

23 May 2011 (has links) (PDF)
Im Sommer 1998 wurden im Auftrag des Sächsischen Landesamtes für Umwelt und Geologie und des Instituts für Geowissenschaftliche Gemeinschaftsaufgaben zwei Forschungsbohrungen in der Lausitz abgeteuft. Sie sollten einen verdeckten vulkanischen Krater erkunden, das Maar von Baruth. Heute kann man mit Recht sagen, dass dieses Ziel erreicht wurde. Die Auswertung der Bohrkerne hat inzwischen viel zum grundsätzlichen Verständnis solcher Maarstrukturen beigetragen. In diesem Heft werden die Bilder der erbohrten Gesteinssäulen publiziert, Meter für Meter. Wissenschaftlern eröffnet sich so die Möglichkeit, den Ablauf der geologischen Prozesse in dem Baruther Maar nachzuvollziehen. Der Beitrag von K. Goth und P. Suhr zur Forschungsbohrung Baruth wird durch weitere Ergebnisse zur Regionalen Geologie von Sachsen ergänzt. K. Huhle berichtet über frühelsterzeitliche Schotter der Freiberger Mulde bei Meißen. J. Klöber; H. Lindner und C. Oelsner erläutern geophysikalische Vermessungen zur Kartierung eines Lamprophyrganges im Elbsandsteingebirge. U. Lehmann dokumentiert die geologischen Verhältnisse, die durch die Auffahrung eines Abwasserstollns im Westerzgebirge freigelegt werden. M. Schade untersucht das Vorkommen von Seifengold in Bächen und Flüssen des Lausitzer Berglandes. M. Schauer und H. Walter zeigen neue Erkenntnisse zum Rotliegend des Briesnitzer Beckens bei Dresden auf. W. Pälchen und E. Geißler fassen die geowissenschaftlichen Arbeiten im Sächsischen Landesamt für Umwelt und Geologie für den Berichtszeitraum von 1997 bis 2003 in einem Tätigkeitsbericht zusammen. Die Ergebnisse der Beiträge informieren über Arbeitsfelder im Umfeld der heutigen Abteilung Geologie im Landesamt und liefern Grundlagen für künftige geologische Arbeiten im Freistaat Sachsen.

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