Day: April 1, 2010

Mapping Rurality: Analysis of Rural Structure in Turkey

/ Matt Artz

International Journal of Agricultural Resources, Governance and Ecology, 2009 – Vol. 8, No.2/3/4 pp. 130 – 157

Aliye Ahu Gulumser, Tuzin Baycan-Levent, and Peter Nijkamp

“The aim of this study is to describe the rural structure of Turkey on the basis of various rural indicators. The data and information used for evaluation of rurality are based mainly on the Turkish Statistical Institute (TURKSTAT) data. Factor analysis, one of the well-known multidimensional techniques is deployed to evaluate rural structure of Turkey while using geographical information system (GIS) based software ArcGIS to map out Turkey’s rurality based on the results of factor analysis. The results of the study show that Turkey is dominantly rural in terms of traditional meaning of rurality while stressing on divergences and differences between Turkey’s provinces. On the other hand, according to the results of the study, in terms of new definition of rural areas as a part of tourism sector, Turkey does not have a dominant rural character.”

Research on Distributed Geo-Computing Oriented Self-organized P2P Network

/ Matt Artz

Proceedings of the Second Symposium International Computer Science and Computational Technology (ISCSCT ’09), Huangshan, P. R. China, 26-28,Dec. 2009, pp. 205-208

Xicheng Tan and Fang Huang

“With the extending of spatial information system into the distributed network environment, it faces some challenges including the mass data character of the spatial data, the limited band width of current network, the devilishly centralized spatial information management and geographic computing resources, as well as the higher requirements of the spatial information service capability. For overcoming these challenges, this paper puts forward a Geo-Computing oriented self-organized P2P network model, and the structure of the P2P network is designed. For performing spatial analysis tasks, the paper also analyzes the spatial data management on the self-organized P2P network. Finally, the test system, which has simulated the slope analyzing based on the self-organized P2P network, is also presented. Compare with the single server based spatial analysis systems the P2P computing based analysis task performs more efficiently and has a better capability of supporting huge amount of requests from the users.”

EDGIS: A Dynamic GIS based on Space Time Points

/ Matt Artz

International Journal of Geographical Information Science, Volume 24, Issue 3 March 2010 , pages 329 – 346

Edward Pultar; Thomas J. Cova; May Yuan; Michael F. Goodchild

“Contemporary GIS can handle static spatial data for querying and visual representation, but the temporal dimension remains a challenge. This paper addresses the need for a dynamic GIS capable of managing complex data types. The design relies on a representation of the theoretical spatiotemporal primitive known as the ‘geo-atom’. This paper proposes a novel and implemented data structure called the space time point (STP) built on this theory. With the STP representation, spatiotemporal data queries can be posed to return useful results about dynamic geographic phenomena and their interaction. Two key challenges addressed in this research are (1) data structures to represent hybrid (object and field) spatiotemporal phenomena and (2) the design of a dynamic GIS interface. These challenges are addressed by the implementation of the system, referred to as ‘Extended Dynamic GIS (EDGIS)’, that uses the proposed STPs. The EDGIS system is described from theory to its implementation in Java™ and a series of application examples are described followed by performance metrics. The paper concludes with a discussion of areas for further research such as integration of the system with geo-sensor networks, hazards, transportation, and location-based services (LBS).”

A Semantic and Language-based Representation of an Environmental Scene

/ Matt Artz

GeoInformatica, Volume 14, Number 3 / July, 2010

Jean-Marie Le Yaouanc, Éric Saux, and Christophe Claramunt

“The modeling of a landscape environment is a cognitive activity that requires appropriate spatial representations. The research presented in this paper introduces a structural and semantic categorization of a landscape view based on panoramic photographs that act as a substitute of a given natural environment. Verbal descriptions of a landscape scene provide the modeling input of our approach. This structure-based model identifies the spatial, relational, and semantic constructs that emerge from these descriptions. Concepts in the environment are qualified according to a semantic classification, their proximity and direction to the observer, and the spatial relations that qualify them. The resulting model is represented in a way that constitutes a modeling support for the study of environmental scenes, and a contribution for further research oriented to the mapping of a verbal description onto a geographical information system-based representation.”

Spatial Dependence of Predictions from Image Segmentation: A Variogram-based Method to Determine Appropriate Scales for Producing Land-management Information

/ Matt Artz / 1 Comment

Ecological Informatics, In Press, Accepted Manuscript, Available online 1 March 2010

Jason W. Karl, Brian A. Maurer

“A significant challenge in ecological studies has been defining scales of observation that correspond to the relevant ecological scales for organisms or processes of interest. Remote sensing has become commonplace in ecological studies and management, but the default resolution of imagery often used in studies is an arbitrary scale of observation. Segmentation of images into objects has been proposed as an alternative method for scaling remotely-sensed data into units having ecological meaning. However, to date, the selection of image object sets to represent landscape patterns has been largely subjective. Changes in observation scale affect the variance and spatial dependence of measured variables, and may be useful in determining which levels of image segmentation are most appropriate for a given purpose. We used observations of percent bare ground cover from 346 field sites in a semi-arid shrub-steppe ecosystem of southern Idaho to look at the changes in spatial dependence of regression predictions and residuals for 10 different levels of image segmentation. We found that the segmentation level whose regression predictions had spatial dependence that most closely matched the spatial dependence of the field samples also had the strongest predicted-to-observed correlations. This suggested that for percent bare ground cover in our study area an appropriate scale could be defined. With the incorporation of a geostatistical interpolator to predict the value of regression residuals at unsampled locations, however, we achieved consistently strong correlations across many segmentation levels. This suggests that if spatial dependence in percent bare ground is accounted for, a range of appropriate scales could be defined. Because the best analysis scale may vary for different ecosystem attributes and many inquiries consider more than one attribute, methods that can perform well across a range of scales and perhaps not at a single, ideal scale are important. More work is needed to develop methods that consider a wider range of ways to segment images into different scales and select sets of scales that perform best for answering specific management questions. The robustness of ecological landscape analyses will increase as methods are devised that remove the subjectivity with which observational scales are defined and selected.”

Review of Climate and Cryospheric Change in the Tibetan Plateau

/ Matt Artz

Environmental Research Letters, Volume 5, Number 1, 2010

Shichang Kang , Yanwei Xu , Qinglong You , Wolfgang-Albert Flügel , Nick Pepin, and Tandong Yao

“The Tibetan Plateau (TP), with an average elevation of over 4000 m asl and an area of approximately 2.5 × 106 km2, is the highest and most extensive highland in the world and has been called the ‘Third Pole’. The TP exerts a huge influence on regional and global climate through thermal and mechanical forcing mechanisms. Because the TP has the largest cryospheric extent outside the polar region and is the source region of all the large rivers in Asia, it is widely recognized to be the driving force for both regional environmental change and amplification of environmental changes on a global scale. Within China it is recognized as the ‘Asian water tower’. In this letter, we summarize the recent changes observed in climate elements and cryospheric indicators on the plateau before discussing current unresolved issues concerning climate change in the TP, including the temporal and spatial components of this change, and the consistency of change as represented by different data sources. Based on meteorological station data, reanalyses and remote sensing, the TP has shown significant warming during the last decades and will continue to warm in the future. While the warming is predominantly caused by increased greenhouse gas emissions, changes in cloud amount, snow-albedo feedback, the Asian brown clouds and land use changes also partly contribute. The cryosphere in the TP is undergoing rapid change, including glacier retreat, inconsistent snow cover change, increasing permafrost temperatures and degradation, and thickening of the active layer. Hydrological processes impacted by glacial retreat have received much attention in recent years. Future attention should be paid to additional perspectives on climate change in the TP, such as the variations of climate extremes, the reliability of reanalyses and more detailed comparisons of reanalyses with surface observations. Spatial issues include the identification of whether an elevational dependency and weekend effect exist, and the identification of spatial contrasts in temperature change, along with their causes. These issues are uncertain because of a lack of reliable data above 5000 m asl.”