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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.
741

Specifying and Detecting Topological Changes to an Areal Object

Jiang, Jixiang January 2009 (has links) (PDF)
No description available.
742

An Embedding Graph for 9-Intersection Topological Spatial Relations

Dube, Matthew P. January 2009 (has links) (PDF)
No description available.
743

Ζωνοποίηση της επικινδυνότητας των κατολισθητικών φαινομένων στον ελληνικό χώρο. Δημιουργία και εφαρμογή μοντέλων με γεωγραφικό σύστημα πληροφοριών

Βασιλειάδης, Ευριπίδης 11 January 2011 (has links)
Ο σκοπός της διατριβής ήταν η συγκριτική έρευνα του κινδύνου των κατολισθήσεων και η δημιουργία ενός μοντέλου εκτίμησής του για τον ελλαδικό χώρο, καθώς και η δημιουργία χαρτών επικινδυνότητας. Για το σκοπό αυτό δημιουργήθηκε η ψηφιακή βάση δεδομένων από 1.238 καταγεγραμμένες κατολισθήσεις για την περίοδο 1903-1998 και ψηφιοποιήθηκαν όλες οι αναγκαίες γεωπληροφορίες, όπως τοπογραφικά ανάγλυφα, τεχνικογεωλογικός χάρτης, γεωτεκτονικοί χάρτες κ.ά. Οι κύριοι παράγοντες που προκαλούν κατολισθήσεις είναι ως γνωστόν οι κλίσεις του πρανούς, τα φαινόμενα διάβρωσης, οι ανθρωπογενείς παρεμβάσεις (π.χ. η κατασκευή οδικού δικτύου), τα κλιματικά χαρακτηριστικά και οι βροχοπτώσεις, τα γεωλογικά και γεωμορφολογικά χαρακτηριστικά των σχηματισμών, τα φυσικά φαινόμενα, όπως οι σεισμοί κ.λπ. Επιλέχθηκαν δέκα (10) παράγοντες-μεταβλητές και διερευνήθηκαν τα γεωγραφικά χαρακτηριστικά της κάθε μεταβλητής με την προβολή της σε πλέγμα 1x1 km. Στη συνέχεια, έγινε η στάθμιση του κινδύνου κατολίσθησης για κάθε μία μεταβλητή, χρησιμοποιώντας τη συχνότητα εμφάνισης σύμφωνα με τις καταγεγραμμένες περιπτώσεις και την έκταση που καταλαμβάνει σε κάθε κατηγορία της μεταβλητής. Αυτή ήταν η πρώτη καινοτόμος ενέργεια της έρευνας. Το επόμενο βήμα ήταν η δημιουργία ένός λογικού–αναλυτικού μοντέλου, όπου ο κίνδυνος εκφράζεται από μια εξίσωση, στην οποία οι δέκα μεταβλητές συνδέονται με βάρη, που εξαρτώνται από την επιρροή που ασκεί η κάθε μεταβλητή. Η ημι-ποσοτική αυτή μέθοδος ανάλυσης κινδύνου αποτελεί προσέγγιση σταθμισμένων γραμμικών συνδυασμών (weighted linear combination - WLC) των δεδομένων εισαγωγής και βασίζεται στις τεχνολογίες των συστημάτων γεωγραφικών πληροφοριών (ΓΣΠ). Τα βάρη εξήχθηκαν αντικειμενικά μέσω της παραγοντικής ανάλυσης των δεδομένων και ο τρόπος εφαρμογής τους ήταν η δεύτερη και καθοριστική ενέργεια της έρευνας, που δίνει ένα πρακτικά εφαρμόσιμο τρόπο εκτίμησης της επικινδυνότητας των κατολισθήσεων, ο οποίος μπορεί να εκσυγχρονίζεται με την εισαγωγή νέων πληροφοριών στην υπάρχουσα βάση δεδομένων. Τα αποτελέσματα επικυρώθηκαν αρχικά χρησιμοποιώντας την προϋπάρχουσα βάση δεδομένων των καταγεγραμμένων κατολισθήσεων, για την οποία δημιουργήθηκε περιβάλλον διεπαφής στο λογισμικό ΓΣΠ. Η επικύρωση των αποτελεσμάτων έδειξε ότι η ενσωμάτωση της μεθόδου WLC και των ΓΣΠ αποτελούν τεχνικές που μπορούν να υποστηρίξουν τεχνικογεωλογικές μελέτες, σχετικά με την επικινδυνότητα των κατολισθήσεων σε ευρύτερη περιοχή. Στη συνέχεια, επιβεβαιώθηκε η αξιοπιστία του μοντέλου επικινδυνότητας και ζωνοποίησης του κινδύνου κατολισθήσεων με την υπέρθεση 397 νέων περιπτώσεων κατολισθήσεων που καταγράφηκαν την περίοδο 1998 - 2003. Συμπερασματικά, από τα αποτελέσματα της διατριβής, προκύπτει ότι τα ΓΣΠ και οι ψηφιακές βάσεις δεδομένων είναι απολύτως αναγκαία μέσα για τη διαχείριση της γεωλογικής, γεωτεχνικής, σεισμικής, βροχομετρικής, οικιστικής κ.λπ. πληροφορίας. Επιπλέον, παρέχουν τη δυνατότητα ολοκληρωμένης ανάλυσης, η οποία διατίθεται από τα συγκεκριμένα εργαλεία χωρικής ανάλυσης, με την επεξεργασία των δεδομένων εισόδου των αναλύσεων και την αξιοποίηση των αποτελεσμάτων, για τη δημιουργία χαρτών εκτίμησης του βαθμού κινδύνου έναντι κατολίσθησης σε μια περιοχή έρευνας. / The objective of this thesis was the comparative study of landslide hazard and the development of a landslide hazard assessment model for the Hellenic territory, and the production of landslide hazards maps. A digital database in a GIS environment was, therefore, developed for the 1.238 recorded landslides from 1903 to 1998, as well as the digitisation of all necessary geo-information, such as topography, engineering geology map, geotectonic zones, etc. The major factors that may cause landslides are altitude, slope, existence of rivers, road construction, climatic features and rainfall, geological and geomorphological features, natural phenomena, such as earthquakes, but also human activities. Hence, these ten variables were selected for further treatment, i.e., rainfall, climatic zone, elevation, lithology, slope gradient, seismic activity (seismic zone), drainage, land use, density of road network, and population density. To begin with, the geographical characteristics of each variable were studied by plotting the primary maps of each variable, as well as the geotectonic map of Greece and the engineering geological map of Greece. Then for each of the ten variables thematic maps were plotted by projecting the data to a 1x1 km grid. Subsequently, each data set was levelled, using the frequency of occurrence and the area that is covered by each category of each variable. This was the one of the innovative actions of this thesis. The second step involved the development of a logical-analytical model, where the hazard is estimated by an expression, where the ten variables are connected with weights, which depend on the area influence exerted by each variable. The semi-quantitative hazard analysis method is an approached of weighted linear combination (WLC) of input data, and it is based on technologies of geographical information systems (GIS). The weights were extracted objectively by factor analysis, and the manner with which they were applied was another and definitive innovation of this study, which offers a practical applicable approach to landslide hazard assessment that can be updated with the entry of new information and data in the existing database. The results of this approach were first verified using the existing landslide database, for which an interface environment within a GIS software was developed. The verification showed that the integration of the WLC method and GIS could support engineering geological studies on the vulnerability of landslides in hazardous areas. The next step was the verification of the landslide hazard and zonation model by the superposition of 397 new landslides covering the period 1998-2003. This thesis comprises of seven chapters. The first chapter makes a general introduction of the physical phenomenon of landslides, their classification, and their descriptive characteristics and describes the factors that contribute in the development of landslides. The second chapter describes the study area, which comprises the whole Hellenic territory, its geomorphological evolution, its geotectonic zones and engineering geological conditions. The third chapter presents the methodologies of geographical information systems, the development of databases and their contribution, as well as a description of the primary reference geographical data. The fourth chapter describes the recording of landslide data, the variables entered in the database, the development of the digital database and the presentation of primary data of the ten variables on maps. The fifth chapter discusses the methods and results of the statistical treatment of the data, and digital maps using a grid of 1x1 km are presented for each of the ten variables with the superposition of the recorded 1238 landslides. The sixth chapter describes the methods of landslide hazard assessment, i.e., (a) using the Poisson distribution to predict the occurrence of landslides over a period of 25 years, and (b) the first innovative step of the development of new landslide hazard assessment model by weighting each variable and the compilation to begin with of weighted maps for each of the ten variables, and then the compilation of a combined Landslide Hazard Assessment Map. The procedure includes the following steps: • The data of each variable were classified into categories, according to international experience and expertise. • Using the 1238 recorded landslides in the Hellenic territory the frequency corresponding to each category was estimated (Fc). • The area in square kilometres that corresponds to each category was estimated (Ac). • The frequency of landslides of each category is divided by the corresponding area (Fc/Ac = Fckm). • The relative frequency was then estimated for each category (R% = [(Fckm/Total Fckm) x 100], giving the value of weighing hazard, and the development of Thematic Maps of Weighting the Landslide Hazard for each of the ten variables. • Factor analysis was used for the extraction of coefficients that were used in the development of the equation of Landslide Hazard, E, at a site, i.e., Landslide Hazard at a site, Ε = {(0.14074 x Rainfall) + (0.13497 x Climatic Zone) + (0.13005 x Elevation in metres) + (0.11602 x Land use) + (0.10957 x Lithology) + (0.10534 x Drainage density) + (0.10207 x Seismic Risk) + (0.06503 x Density of road network) + (0.05056 x Slope gradient) + (0.04559 x Population density)} The final result for each pixel of 1x1 km (n=131.968) is expressed as a percentage, giving, therefore, the Probability of Landslide hazard at a site, i.e., Probability of occurrence of a landslide at a site, P=(Ε / 0.25948885430348) x 100 Where, Ε is the value of Landslide hazard at a site Whereas the 0.25948885430348 is the maximum for Ε • Finally, the combined weighted landslide hazard map was compiled using the digital thematic maps of each variable, and reclassifying the classes into new ones, based on the unit relative frequency. On this Landslide Hazard Assessment Map, the 1238 landslides were superimposed in order to test the validity of the model. The coincidence of the recorded landslides with the defined landslide hazard zones is comparatively quite good. It can be said that this was expected, since the derived model used the 1238 landslides. The Landslide Hazard Assessment Model was, however, verified by using 397 new landslides recorded during the period from 1998 to 2003. The coincidence with the defined Landslide Hazard Zones is unbelievably very good, proving that the methodology used is viable. The seventh chapter summarises the results of the thesis, and includes the final conclusions. Finally, according to the results stemming from this thesis, GIS and digital databases proved to be indispensable tools for managing geological, geotechnical, seismic and climatic information. Moreover, they offer the potential of a complete analysis, using tools of spatial analysis, as well as the implemented algorithms in order to produce landslide hazard assessment models.
744

Μελέτη φυσικών καταστροφών στο Ν.Α. άκρο του ελληνικού ηφαιστειακού τόξου - νήσος Νίσυρος - με την χρήση Συστήματος Γεωγραφικών Πληροφοριών (ΓΣΠ)

Λέκκα, Καλλιόπη 18 April 2011 (has links)
Στα πλαίσια αυτής της εργασίας επιχειρήθηκε ο εντοπισμός εκείνων των περιοχών στη νήσο Νίσυρο που εμφανίζουν αυξημένο κίνδυνο εμφάνισης κατολισθήσεων στα φυσικά πρανή εστιάζοντας στα ποιοτικά κριτήρια που τις επηρεάζουν (γεωλογία, κλίση, καμπυλότητα και προσανατολισμός πρανούς, υψόμετρο) και η δημιουργία ζωνών βαθμού κινδύνου εμφάνισης κατολισθήσεων για το σύνολο της περιοχής. Η μελέτη στηρίχτηκε στην υπέρθεση χαρτών που περιγράφουν τους παραπάνω παράγοντες, χρησιμοποιώντας ταυτόχρονα τα κατάλληλα βάρη ως προς την επιρροή τους στο φαινόμενο των κατολισθήσεων. Η επεξεργασία των δεδομένων και η εφαρμογή της μεθοδολογίας έγινε σε περιβάλλον Arc Map. / -
745

Applying GIS in the evaluation of landscape aesthetics

Fourie, Rene 04 1900 (has links)
Thesis (MA (Geography and Environmental Studies))--University of Stellenbosch, 2005. / Scenic beauty, or landscape aesthetics, should be regarded as a valuable resource, to be protected and enhanced in order to generate income. Current environmental impact assessment (EIA) studies do not include the evaluation of scenic beauty as a resource properly, due to the lack of effective evaluation methods. A general dilemma lies in objectively evaluating beauty. If scenic preferences can be associated consistently with the physical landscape features, the latter can be used as predictors of the former. Analysis of aesthetics can therefore be done with a degree of objectivity, based on these general preferences. A large number of these preferences are morphologically measurable. In other words, these preferences can be mapped in a Geographical Information System (GIS), rated, and evaluated quantitatively. The first step in objectively evaluating landscape aesthetics entailed identification and compilation from the literature of conceptual components in a landscape, i.e. the units defining a landscape. Four components were identified: landform, vegetation, water features and man-made features. Each of the four components can be subdivided into several elements. Secondly, scenic preferences that can be consistently associated with landscape features were identified. It was found that any subjective experience of landscape aesthetics would be either one of calmness or one of excitement. The presence or absence of the landscape elements, and specific combinations of elements and element variables within the context of an individual landscape, will determine the type and extent of the aesthetic experience of the viewer. Finally, this theory was put into practice. Coverages were created of a test region, with landscape elements as the features of the coverages, and element variables or characteristics as feature attributes. These landscape elements, as they enhance either calmness or excitement, were quantified by assigning value ratings to the elements according to the extent of the influence of the elements on the aesthetic value of the landscape. ArcInfo GRID functionality was used to convert the coverages to raster (or grid) overlays, using the element variables enhancing both calmness and excitement. A simple cumulative summing function was used to derive an aggregate Calm Aesthetic Experience map by adding grids enhancing calmness. An aggregate Exciting Aesthetic Experience map was constructed by adding grids enhancing excitement. Finally, these two grids were summed in order to construct a Total Aesthetic Experience map, which is an indication of the total aesthetic value of the test region. The outcome of this research was a method for analysis and objective evaluation of a landscape, using a GIS for data creation, analysis and map construction. The resultant map is an indication of aesthetic value, showing the test region graded according to intrinsic aesthetic value.
746

'n GIS ondersoek na die kultuurtoerisme-potenisaal van Mechelen, België en die rol van kulturele toerisme in stedelike hernuwing

McKechnie, Jennifer Joan 03 1900 (has links)
Thesis (MA)--Stellenbosch University, 2000. / ENGLISH ABSTRACT: Tourism is a global growth industry. Large cities are prominent tourist destinations and are therefore the focus of tourism studies. Because cultural tourism can act as a lever for the urban economy, cities are increasingly investigating historical heritage as a resource in developing cultural tourism. Furthermore, many opportunities for development exist as these tourism products are characterised by adaptability, flexibility and a wide-ranging nature. Development of the historical heritage of tourist attractions is especially noted in Europe. The rich historical heritage and unique cultural activities of these cities can be used to attract visitors. This study utilises the geographical information system (GIS) programmes TransCAD, ArcView and ARC/INFO to investigate the cultural tourism potential of Mechelen in Belgium. GIS is particulary well suited for spatial analyses in tourism studies. It was assumed that two factors - location and function - will influence the tourism potential of historical buildings. In investigating the morphological location of buildings, the grouping of buildings around pre-selected marker buildings in Mechelen was considered. Functional analyses considered the current function of historical buildings and the attractiveness of the respective functions to tourists. Concurrent analyses of these two factors resulted in deductions regarding the tourism potential of the individual historical buildings. Furthermore, areas with high development potential were identified. The identification of such areas contributes to effective development planning and sustainable development. By targeting development visitors are attracted which supports optimal utilisation of tourist resources by residents. Well planned, targeted development thus increases the contribution that cultural tourism can make towards the urban economy. / AFRIKAANSE OPSOMMING: Toerisme is 'n wêreldwye groei-industrie. Omdat groot stede die belangrikste toerisme-bestemmings is, geniet hulle baie aandag in toerisme-studies. Die historiese erfenis van stede word toenemend as hulpbron vir die ontwikkeling van kulturele toerisme ondersoek omdat dit as 'n hefboom vir die bevordering van die stedelike ekonomie kan dien. Daarbenewens is daar talle moontlikhede vir ontginning, omdat die kulturele toerisme-produk gekenmerk word deur aanpasbaarheid, buigsaamheid en 'n wyd omvattende aard. Die ontwikkeling van die historiese erfenis van toeriste-aantreklikhede word veral in Europa waargeneem. Die meeste Europese stede is ryk aan historiese erfenis en unieke kulturele aktiwiteite wat gebruik kan word om besoekers te trek. In dié studie word die geografiese inligtingstelsel (GIS) programme TransCAD, ArcView en ARC/INFO ingespan om die kulturele toerismepotensiaal van Mechelen, België, te ondersoek. GIS is besonder geskik vir die doen van ruimtelike analises in toerismestudies. Daar is van die uitgangspunt uitgegaan dat twee faktore die toerismepotensiaal van historiese geboue beïnvloed, naamlik ligging en funksie. Wat die morfologiese ligging betref, word gekyk na die groepering van historiese geboue rondom sekere vooraf geselekteerde beeldbepalergeboue. In die funksionaliteitsanalises word daar gelet op die huidige funksies van die individuele historiese geboue en die aantreklikheid van die onderskeie funksies vir toeriste. Deur gelyktydig na dié twee faktore te kyk, is afleidings gemaak oor die toerisme-potensiaal van die individuele historiese geboue. Gebiede met 'n hoë potensiaal vir ontwikkeling is geïdentifiseer. Die identifisering van gebiede wat meer gunstig vir toerisme-ontwikkeling is, dra by tot beter ,ontwikkelingsbeplanning en volhoubare ontwikkeling. Geteikende ontwikkeling maak die stad meer aantreklik vir besoekers en dra daartoe by dat die inwoners van die stad optimaal voordeel kan trek uit die besoekende toeriste. Goed beplande, geteikende ontwikkeling vergroot ook die bydrae wat kulturele toerisme in die stimulering van die stad se ekonomie kan speel.
747

Using geographical information systems for mapping commercial farmers' perceptions on land reform in Mpumalanga, RSA

Van Deventer, Heidi 03 1900 (has links)
Thesis (MA)--Stellenbosch University, 2000. / ENGLISH ABSTRACT: Traditional top-down decision-making models have become unpopular since public institutions have been demanding more democracy at local level. New approaches and techniques have focused on how the majority of people can be involved in a bottom-up approach to development and decision making. Techniques, such as Participatory Rural Appraisals (PRAs), have identified people's concerns regarding the use of natural resources centred on land issues. Land is essentially a subject of public concern. Land as a spatial phenomenon controlled politically and used by all for survival and other purposes needs to be assessed in an integrated and time-spatial way for better planning and decision making. Geographical Information Systems (GISs) have often been used by statutory "experts" in evaluating, analysing and mapping of land and land-related features. GISs have a lot of potential in being applied as decision-making tools. If this is the case, how can public perceptions and politics be presented and mapped in a GIS to improve and democratise decision making even further? The study has investigated new methods of representing people's perspectives at grassroots level in a non-traditional way. A sub-region of the Lowveld, situated in the Mpumalanga province, has been selected because of the various kinds of land owners in the region. The Kruger National Park lies to the east of the study area, from where some black communities claim to have been removed. To the west of that is one of the districts of the former homeland KaNgwane, namely Nsikazi, and west of that two areas of intensive large-scale commercial fruit and vegetable production in the Nelspruit-White River and Kiepersol-Hazyview areas. Towards the escarpment north-west of these lie large commercial exotic forest plantations, owned mainly by Safcol and MandL Given the high demand and need for land from the overpopulated Nsikazi district, the process of land reform is a matter of great concern. White male commercial farmers in both regions where commercial farming is active were interviewed about their knowledge and perceptions of land reform. Various themes were presented to the farmers to comment on, namely the history of forced removals, land use, land potential, hydrology and where land reform should take place. Interviews were taped in Afrikaans, transcribed and translated to English. "Mental maps" were drawn on tracing paper overlaid on topographical maps of the Land Surveyor General, Mowbray. These were digitised and managed in Arclnfo, and displayed and analysed in ArcView, from where output maps were produced. The results of this technique proved to be very useful and can certainly broaden the use of GISs in decision making and public participation. However, GISs alone cannot be seen as the solution to better development and better decision-making. Public participation is of the utmost value in facilitating and initiating these processes. Land use planning needs to be the responsibility and concern of all land users and owners at a local level, where GISs can be applied as a tool to provide easier and more effective analysis and results for the implementation of initiatives. / AFRIKAANSE OPSOMMING: Tradisionele bo-na-onder besluitnemingsmodelle het in die laaste paar dekades baie ongewild geraak met die totstandkoming van instellings wat die publiek se mening hoog ag en demokrasie op grondvlak probeer bevorder. Nuwe benaderings en tegnieke poog nou om die publiek se mening in 'n onder-na-bo benadering tot ontwikkeling en besluitneming te integreer. Grondhervorming is basies die erns van die publiek, meer so as die staat. Grond is 'n ruimtelike verskynsel wat polities beheer word maar deur die meerderheid gebruik word vir oorlewing asook ander doeleindes. Dit behoort op 'n tyd-ruimtelike basis op 'n geïntegreerde wyse vir beter beplanning en besluitneming ondersoek te word. Geografiese Inligtingstelsels (GISs) word hoofsaaklik deur statutêre "kenners" gebruik in die evaluering, analise en kartering van grond en verbandhoudende verskynsels. Dit beskik verder oor die potensiaal om in besluitnemingsprosesse gebruik te word. Die vraag ontstaan egter hoe die publiek se menings en politieke strukture met 'n GIS verteenwoordig en gekarteer kan word ter verbetering van besluitneming op 'n meer demokratiese wyse. Die studie het nuwe metodes ondersoek waarvolgens mense op grondvlak se persepsies op nie-tradisionele maniere verteenwoordig en ondersoek kan word. 'n Sub-streek van die Laeveld wat geleë is in die Mpumalanga provinsie, is geselekteer vanweë die verskeidenheid grondeienaars wat daar voorkom. Die Kruger Nasionale Park is geleë in die oostelike deel van die studiegebied vanwaar sekere swart gemeenskappe gedurende die Apartheidsregime verskuif is. Direk wes hiervan lê die voormalige tuisland KaNgwane se Nsikazi distrik en wes daarvan twee areas, naamlik Nelspruit-Witrivier en Kiepersol-Hazyview, waar die kommersiële boerdery van vrugte en groente op groot skaal beoefen word. In die noordwestelike gedeeltes van die studiegebied kom grootskaalse uitheemse bosbouplantasies voor wat aan Safcol en Mondi behoort. Met die stygende aanvraag na grond vir residensiële- en landbougebruik in die streek, veral vanuit die Nsikazi distrik, is grondhervorming en die toepassing daarvan, 'n probleem, indien nie 'n bedreiging, vir die meeste grondeienaars. Onderhoude is met blanke manlike kommersiële boere, in albei die kommersiële streke gevoer om hul menings en kennis van grondhervorming te ondersoek. Verskeie temas is as besprekingspunte gestel, naamlik die geskiedenis van gedwonge verskuiwings, grondgebruik, grondpotensiaal, water hulpbronne en waar hul meen grondhervorming sou moes plaasvind. Onderhoude was in Afrikaans opgeneem, getranskribeer en in Engels vertaal. "Kognitiewe kaarte" was op deursigtige papier geteken wat oor 'n reeks topografiese kaarte van die gebied gelê is. Die resultate is versyfer en in Arelnfo gemanipuleer en daarna in ArcView ontleed en vir verslaglewering gekarteer. Die resultate van die tegniek beloof om vir beide besluitnemers en die publiek as deelnemers in die proses baie bruikbaar te wees. Dit verbreed ook die gebruik en toepassing van GISs en die sisteem se vermoëns. GISs kan egter nie alleenlik aangewend word om ontwikkeling en besluitneming vir die publiek beter of meer aanvaarbaar te maak nie. Alle mense se deelname is van die uiterste belang en waarde in die inisiëring, fasilitering en implementering van strategieë en projekte. Grondgebruiksbeplanning moet die verantwoordelikheid van almal word wat grond op plaaslike vlak gebruik of besit, nie net van die wat deur 'n probleem of program, soos grondhervorming, geraak word nie. 'n GIS kan aangewend word om die prosesse van ontwikkeling en besluitneming te vergemaklik deur analises vinniger en op 'n meer effektiewe manier te ondersoek vir beter en meer demokratiese besluitneming.
748

Ontwikkeling van 'n driedimensionele netwerkmodule vir optimale roetebepaling

Van Lill, S. W. P. (Schalk Willem Petrus) 12 1900 (has links)
Thesis (MA)--Stellenbosch University, 2001. / ENGLISH ABSTRACT: A shortest or most economical route can easily be determined by using a geographical information system (GIS). Unfortunately, most systems compute distances in two dimensional space. As computer-technology moves towards three dimensional applications, it is essential that GIS keeps up with this trend. In this research, the network module of Arc View (using Avenue) is customized, so that topographical slope is considered in determining the shortest or most economical route. Two buttons were added to the normal Arc View interface. By doing it this way, the user has the full functionality of Arc View, as well as the use of the new application. One button initiates a dialogue for capturing the economic parameters (fuel efficiency, oil usage, tyre usage, maintenance costs and capital costs) of a vehicle. The other button selects a route network and uses a vehicle's economic parameters (as determined by the user) to calculate a most economical route. This thesis describes the procedure, logic and methodology followed in adding a most economical route-selection function to Arc View. It also demonstrates the importance of incorporating three dimensional space for determining a most economical route. The new function currently calculates a most economical route, based on vehicle running costs for Heavy Goods Vehicles (HGV's). The application performs satisfactorily, but there is scope for further development and refinement, both of the economical formulae for computing costs as well as of the graphic user interface (GUl). The flexibility of the system can be enhanced by providing for additional classes of vehicles. / AFRIKAANSE OPSOMMING: 'n Kortste of mees ekonomiese ritroete kan maklik met behulp van 'n GIS (Geografiese Inligtingstelsel) vasgestel word, maar die meeste stelsels bereken afstande in 'n plat vlak (in twee-dimensionele ruimte). Soos die rekenaartegnologie ontwikkel, word meer drie-dimensionele ruimtelike toepassings geskep, dus moet GIS-tegnologie ook toenemend die derde dimensie inkorporeer. In hierdie navorsing is Arc View se netwerk module met Avenue aangepas dat dit topografiese helling outomaties inreken by die bepaling van 'n kortste of mees ekonomiese roete. Twee knoppies is tot die normale Arc View koppelvlak bygevoeg. Deur dit so te doen, het die gebruiker toegang tot die volle funksionaliteit van Arc View en dié van die nuwe funksie. Een knoppie inisieer die koppelvlak waarmee die ekonomiese parameters (brandstof verbruik, olie verbruik, band verbruik, kapitaal koste en onderhoudskoste) van 'n voertuig opgestel word. Die ander knoppie selekteer 'n padnetwerk en gebruik 'n voertuig se ekonomiese parameters (soos gedefinieer deur die gebruiker) om 'n mees ekonomiese roete vas te stel. Hierdie tesis beskryf die prosedures, logika en metodologie waarvolgens die nuwe roeteseleksie funksie by Arc View geïnkorporeer is. Dit het ook gedemonstreer dat dit noodsaaklik is om drie-dimensionele ruimte by die bepaling van 'n mees ekonomiese roete in te sluit. Die nuwe funksie bepaal tans 'n ekonomiese roete gebaseer op die voertuig-loopkoste van swaarvoertuie. Dit funksioneer bevredigend, maar daar is steeds moontlikhede vir verdere ontwikkeling en verfyning, beide van die ekonomiese kosteberekeningsformules en die gebruikers-koppelvlak. Deur ook vir ander klasse voertuie voorsiening te maak kan die plooibaarheid van die stelselook uitgebrei word.
749

The development of a visualization tool to assist topographic map users

Van den Heever, Johannes Lodewikus 12 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2002. / ENGLISH ABSTRACT: The recognition and description of relief features from their contour patterns is recognized as the main challenge in topographic map education. Conducting field exercises can solve this problem, but can be very time consuming. Modern technology, however, provides an alternative teaching technique by creating depictions of terrain. Important issues raised by this new approach include questions such as what these depictions should look like and how it should be presented to the user. Research presented here aims to address these issues by constructing design guidelines for terrain depiction. These design guidelines were derived from previous research and case studies. The guidelines focussed on research about how people perceive different representations of terrain and how these representations should optimally be presented. The design guidelines were constructed from research done in diverse fields such as cognitive psychology, cartography and engineering. Results of this research revealed that in order to develop an effective terrain visualization tool, it is crucial to incorporate different fields of expertise. The design guidelines were implemented with ArcView GIS and its 3D Analyst extension, which has the ability to display spatial data in three dimensions. The final product is called Terrain Visualization Tool 1.1 (TVT) and was created by customizing an ArcView GIS project (TV BUILDER) and constructing a Website (TV VIEWER). TV BUILDER creates the visualization data in the form of 20 web pages per topographic area and links them to TV VIEWER that serves as a platform to view the data. The design guidelines were implemented successfully and show the advantages of using Geographical Information Systems (GIS) in related research. / AFRIKAANSE OPSOMMING: Die identifisering en beskrywing van landskapelemente vanaf hul kontoere is geidentifiseer as die primere uitdaging in topografiese kaartonderrig. Hierdie probleem kan oorkom word deur kaartleesoefeninge in die veld te onderneem, maar dit neem baie tyd in beslag. Modeme tegnologie maak ‘n alternatiewe onderrigmedium moontlik deur die skep van verskillende landskapsuitbeeldings. Hierdie alternatief laat die vraag ontstaan hoe die uitbeeldings moet lyk en hoe dit aan die gebruiker aangebied moet word. Die doel van hierdie navorsing spreek hierdie vrae aan deur ontwerpriglyne vir landskap uitbeelding daar te stel. Die ontwerpriglyne is saamgestel deur bestudering van vorige navorsing en studies wat op hierdie gebied gedoen is. Die riglyne fokus veral op navorsing wat mense se reaksie op verskillende landskapuitbeeldings ondersoek. Die ontwerpriglyne is egter saamgestel deur navorsing wat gedoen is in velde soos kognitiewe sielkunde, kartografie en ingenieurswese. Hierdie navorsing het bewys dat inkorporasie van verskillende studievelde in die ontwikkeling van terrein visualiseringstoepassings essensieel is. Die riglyne is geimplementeer deur gebruik te maak van ArcView GIS en die 3D Analyst uitbreiding wat die vermoe het om data in drie dimensies uit te beeld. Die finale produk genaamd Terrain Visualization Tool 1.1 (TVT) bestaan uit twee komponente, naamlik ‘n aangepaste ArcView GIS projek (TV BUILDER) en ‘n webwerf (TV VIEWER). TV BUILDER skep die landskapsuitbeeldings van een topografiese area in die vorm van 20 web bladsye en verbind dit met TV VIEWER, wat as ‘n platform dien om die landskap uitbeeldings te beskou. Die ontwerpriglyne is suksesvol geimplementeer, wat die voordele van Geografiese Inligtingstelsels (GIS) in hierdie en soortgelyke toekomstige navorsing demonstreer.
750

Geographical information systems for environmental impact assessment : a feasibility study

Brink, Ester 12 1900 (has links)
Thesis (MA)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: This study acknowledges the status quo in South Africa as a country in transformation. Leaders concur that people live under the spell of the evil triplets of poverty, inequality and unemployment amidst the need for development and economic growth. In order to initiate positive change, the 1996 Constitution of South Africa supports integrated environmental management (IEM) and sustainability principles towards ecological, economic and social compromise. Furthermore, the National Environmental Management Act (NEMA) was legislated in 1996 along with the mandatory environmental impact assessment (EIA) tool in 1998. Despite this legislation being of global standards, current discourse highlights the need for new strategies and tools to improve IEM. The constraint lies in the implementation of policy as the EIA process is limited by inconsistency and project specific focus. Fortuitously technology has developed to levels where web-based tools encourage spatial awareness and individual responsibility for the environment. Usage of participative GIS supported by best practice in governance has the potential to successfully drive IEM. This research builds on the integration of a policy instrument (EIA), spatial technology (GIS), development and human factors (people) as pillars of transdisciplinary methodology to collaborate and gather new information to expand knowledge and augment existing processes. The study objectives required rigorous research and involved a wide range of participants in a feasibility study to provide details of the viability of integrating GIS usage into EIA conduct in South Africa. Participants in the research were selected from the geographical scope of Cape Town and represent involved parties in EIA and potential users of GIS in EIA. The legislative scope is the Western Cape Province. Triangulation, a mixed method approach, was employed to collect and collate qualitative and quantitative information based on the opinions of involved parties in the IEM, EIA and GIS domains. Primary data collection methods included observation, fieldwork, informal, formal and focus group discussions as well as an e-mail questionnaire and a Likert scale e-survey. The knowledge gained was evaluated using SWOT and graphics. The findings indicated that the majority of participants agreed that technology and skills are available to design and develop a web-based application for GIS usage in EIA. However, from the outcome of the study the main challenge is not related to technical skills and capacity, but to align the EIA with IEM sustainability principles for effective decision making and self-regulation. It is therefore envisaged that web-based GIS usage in EIA based on IEM has the potential to reconnect the EIA process by uniting people in knowledge with easy access to information from a central data base repository to an on-line web-based platform that links time and space to inform decision making. / AFRIKAANSE OPSOMMING: Die uitgangspunt van hierdie studie is dat Suid-Afrika 'n land in transformasie is en die behoefte aan ontwikkeling en ekonomiese groei van kardinale belang is weens die armoede, ongelykheid en werkloosheid waaronder baie mense lei. Effektiewe omgewingsbestuur is uiters belangrik om omgewingsbesoedeling en agteruitgang te verhoed. Ten einde 'n positiewe verandering te inisieer, ondersteun die 1996 Grondwet van Suid-Afrika geïntegreerde omgewingsbestuur (GOB) en volhoubaarheidsbeginsels teenoor ekologiese, ekonomiese en sosiale kompromie. Die 1996 Nasionale Wet op Omgewingsbestuur (NEMA) het die omgewingsimpakstudie (OIS)-instrument in 1998 verpligtend verklaar. Die OIS wetgewing is gebaseer op hoë internasionale standaarde, maar ten spyte hiervan beklemtoon die huidige diskoers die behoefte aan nuwe strategieë om OIS in die praktyk effektief te belyn met die GOB beleid. Tans word die OIS proses beperk deur teenstrydigheid tussen gebruikers van die proses sowel as projekspesifieke fokus. Tegnologie het ontwikkel tot 'n vlak waar webgebaseerde GIS ruimtelike bewustheid aanmoedig en individuele verantwoordelikheid vir die omgewing aanbeveel en ondersteun word. Deelnemende GIS, ondersteun deur goeie regering, het die potensiaal om OIS en GOB suksesvol in die praktyk te implementer. Hierdie navorsing bou voort op die integrasie van 'n beleidsinstrument (OIS), ruimtelike tegnologie (GIS) asook ontwikkeling en menslike faktore (mense) en ondersteun die transdissiplinêre metodologie om nuwe inligtig te versamel en vryelik te deel. Die studiedoelwitte het streng navorsingsmetodologie vereis deur 'n wye verskeidenheid van deelnemers te betrek in 'n ondersoek na die haalbaarheid van die integrasie van GIS gebruik in OIS in Suid-Afrika. Deelnemers aan die navorsing is gekies uit die geografiese domein van Kaapstad en was betrokke partye in omgewingsbestuur en potensiële gebruikers van GIS in OIS. Die wetgewende domein is die Wes-Kaap. 'n Gemengde-metode benadering is gevolg om kwalitatiewe en kwantitatiewe inligting te versamel en was gebaseer op die menings van die betrokke partye in die IEM, OIE en GIS terreine. Die kennis is geëvalueer met behulp van SWOT analise en grafika. Die bevindinge dui aan dat die meerderheid van die deelnemers saamstem dat tegnologie en vaardigheid beskikbaar is om 'n program vir GIS-gebruik in OIS te ontwikkel. Die uitslag van die studie dui daarop dat die grootste uitdaging vir effektiewe besluitneming en self-regulering nie verband hou met tegniese vaardighede en kapasiteit nie, maar om die OIS te verenig met GOB-volhoubaarheid beginsels. Die vooruitsig is dus dat web-gebaseerde GIS gebruik in OIS gebaseer op GOB die potensiaal het om mense met kennis te verenig en omgewingsbestuur effektief in te lig.

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