Markov Model and Cellular Automata for Vegetation  

Author:

Cheng-Liang Chang,

Jui-Chin Chang

 

Original Tittle:

Applications of Markov Model and Cellular Automata for Vegetation Recovery Simulation: A Case Study of Mount Jiou Jiou Area

Abstract:

The recovery of vegetation is the most significant landscape in the terrestrial globe. In recent years it has been changed rapidly due to human socio-economic growth and environmental impact. Therefore, many research methods have been applied so as to comprehend and forecast these dynamic changes.  This paper intends to apply some of theses methods and processes to quantify the change of vegetation recovery in Mount Jiou Jiou area. First of all, the graphic data of study area is collected by using the SPOT satellite images of four representative periods (Mar.1999, Oct.1999, Nov.2002 and Nov.2005).  Subsequently the vegetation types and their changes are examined through the Normalized Difference Vegetation Index (NDVI) analysis. Second, the Geographic Information System (GIS) technology is adopted to recognize the distributions of different vegetation types, characteristics of topography and their correlation. Finally, by combining the methods of Markov chains and Cellular automata this study models and simulates the spatio-temporal change of vegetation recovery. The results can be summarized as follow: (1) After 921 earthquake, 80% of vegetation on Mount Jiou Jiou area was destroyed seriously in 1999, therefore the index of NDVI was very low. After that, the vegetation is recovered gradually for recent years under stable weather conditions. (2) The healing situation of vegetation is intensely affected by geomorphologic factors, such as height, slope and aspect. (3).After comparing two models testing, the present study shows that CA-Markov model is more suitable for simulating the change trend of vegetation recovery.

 

Language:

Chinese

 

Publisher:

Journal of Geographical Research No.45, November 2006

 

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Environmental Mapping Based on Spatial Variability  

Author:

Nelley Kovalevskaya and Vladimir Pavlov

Abstract:

Environmental maps show the probable environmental states of different types of land use or development of landscape in a geographic context. Remotely sensed data are particularly efficient for environmental mapping in order to outline major environmental types. Multiple schemes of image classification used in environmental mapping are either traditionally statistical or heuristic. While the former methods do not take account of spatial variability in space and aerial data, the latter ones does not lend themselves to optimal solutions we present.  Novel probabilistic models of piecewise-homogeneous images are used in environmental mapping to segment real images. The models consider both an image and a land cover map. Such a pair constitutes an example of a Markov random field specified by a joint Gibbs probability distribution of images and maps. Parameters of the model are estimated by using a stochastic approximation technique. Its convergence to the desired values is studied experimentally. Addition of spatial attributes appears to be necessary in most areas where the differences in spatial data between regions in the image occur. Experiments in generating the pairs of images and environmental maps and in segmenting the simulated as well as real images are discussed.

Publisher:

Journal of Environmental Quality 31:1462-1470 (2002)
© 2002

Article Credit:

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Three-dimensional modelling of thrust-controlled foreland basin stratigraphy  

Abstract:

In this thesis a tectono-sedimentary forward model has been presented, devised to simulate sediment erosion and deposition in a coupled drainage basin - foreland system, as well as accumulating a three-dimensional stratigraphy.

The aim of the research was to investigate which features recorded in the foreland basin architecture are diagnostic of the balance and interplay between two main external forcings: repeated tectonic activity and eustatic sea-level variation. Special attention has been paid to differences in stacking patterns of fluvial depositional systems and the character of the sequence-bounding unconformities.

The sediment yield generated by fluvial bedrock erosion in the orogenic drainage basins has the typically asymmetrical shape of a response curve (Chapter 2). Yield gradually increases during tectonic activity, and declines exponentially during tectonic quiescence. Syn-tectonic yields are increasing, but they are not sufficient to completely fill the accommodation space created in the adjacent foreland basin due to flexural response upon active tectonic thrust loading. As a result and counter-intuitively, deposition of alluvial fan gravels in the foreland basin retreats during tectonic activity, whereas progradation is characteristic of phases of tectonic quiescence and reduced flexural subsidence. A history of pulsating tectonic activity is reflected in the alluvial architecture of the basin as a succession of coarsening-up, prograding gravel sheets that laterally connect during quiescence, and alternate with basin-wide onlap of fine-grained sediments marking renewed tectonic activity.

The experiments of Chapter 3 show that there are two contrasting types of sequence boundaries developed in the alluvial stratigraphy when a eustatic sea-level variation is superposed upon the alternation of tectonic activity and subsidence:

A) During intervals of tectonic activity, eustatic fall and rise of sea level form prograding, shallowing up sequences, which are bounded by Type-2 unconformities and subsequent flooding surfaces. The syn-tectonic, high flexural subsidence rates prohibit the sea level to drop below the delta break in slope, safeguarding the stratigraphy from severe incision.
B) During intervals of tectonic quiescence, Type-1 unconformities are formed, because eustatic falls now drop below the delta break in slope, as they are no longer compensated by the subsidence component in relative sea level. Because multiple eustatic sea-level cycles may occur during a quiescence interval, the resulting Type-1 unconformity at the base of the delta-top sheet sandstone can be a composite and therefore poor time marker.

The suites of amalgamating, axial channel belts that characterize this delta top sheet sandstone have a preference for the depression between the basin-margin alluvial fans and the conical delta surface that was formed during a previous tectonic phase.

Similar suites of amalgamating axial channel belts are created when the foreland basin is detached from its substratum by a hinterland-dipping sole thrust and transformed into a thrust-sheet top basin (Chapter 4). In the light of these model results the Eocene Castissent Formation in the Pyrenean Tremp Basin, previously interpreted as a incised valley system, is explained as a phase of moderate tectonic reduction of the accommodation space. This mechanism explains the continuous marine influence on the delta plain simultaneous with a forced regression and increased sandstone interconnectedness at the cost of fine-grained intervals.

Publisher: Three-dimensional modelling of thrust-controlled foreland basin stratigraphy / Quintijn Clevis - [S.l.] : [s.n.], 2003 - Tekst. - Proefschrift Universiteit Utrecht

NBC: 38.41: sedimentatie

 

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  • Title
  • Contents
  • Chapter 1: Introduction
  • Chapter 6: Conclusions
  • References
  • Samenvatting
  • Dankwoord-Acknowledgements
  • Curriculum Vitae
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    Presentation of geological date in Geographic information systems  


    Author: Blišťan Peter


    Abstract:

    Thematic maps, models and space simulations 3D are frequent form of geological data in GIS. Thematic maps and spatial should represent models date quantitative and qualitative measurement and ground laboratory study in an appropriate form. Point line of the use of trademarks and form of qualitative dates in a practice.On creating thematic maps, models and computer simulations to work together. Researchers and engineers from various special-oriented (geologist, surveyors, builder, ecology, programmer) working together on the creation of thematic maps, the different models and computer simulation. It is important that all the directions and methodological principles were observed in the creation of GIS because GIS can be accumulated in practice not to use.


    Journal: Acta Montanistica Slovaca Year: 2007 Vol: 12 Issue: speci 3


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