Urban Landscape Pattern Research Articles

Ecological analysis of an emerging urban landscape pattern—desakota: a case study in Suzhou, China

Recent scholarly efforts to investigate the conventional wisdom of urban transition and conceptualize the distinct patterns of urbanization emerging in China, simply referred to as “desakota”, have not yielded any conclusive validation. The possible existence of “desakota” is significant for landscape ecology and regional science research in that it challenges long cherished Western notions concerning the separation of urban processes from rural processes and the spatial uniqueness of the respective landscapes. This paper examines physical evidence of desakota from land use changes and tempo-spatial dynamics of desakota development in the lower Yangtze River Delta—one of the most populous and rapidly growing economic regions in China. The paper uses satellite data in 1990, 1995 and 2000 to spectrally disaggregate such rural landscape patterns as urban construction expanding from existing commercial and industrial centers, rural non-agricultural construction, special large infrastructure construction, and crop cultivation. The paper inspects one transect (60 km long and 12 km wide) cutting across Suzhou City in south and Changshu City in north. The transect is divided into four segments to investigate quantitative changes of land types between the two cities over time. The paper applies landscape ecological metrics to analyze tempo-spatial patterns of desakota changes in terms of counts, densities, shapes, compositions, spatial relationships and diversities. The paper concludes: (1) desakota occurred in Suzhou area before 1990 and witnessed two phases of development, dramatic expansion between 1990 and 1995 and consolidation during 1995–2000; (2) desakota dynamics show distinct spatial patterns, new growth of large and specialized urban districts dominant in the vicinity of large cities (Suzhou) and incremental expansion of existing urban places in small cities and rural areas; and (3) landscape metrics are very informative in discerning dynamics and patterns of land use and land cover changes and different metrics vary in descriptive power and sensitivity.

Impacts of road corridors on urban landscape pattern: a gradient analysis with changing grain size in Shanghai, China

Urbanization is one of the most important driving forces for land use and land cover change. Quantifying urban landscape pattern and its change is fundamental for monitoring and assessing ecological and socioeconomic consequences of urbanization. As the largest city in the country, Shanghai is now the fastest growing city in China. Using land use data set of 2002 and combining gradient analysis with landscape metrics, we analyzed landscape pattern of Shanghai with increasing grain size to study the impacts of road corridors on urban landscape pattern. Landscape metrics were computed along a 51×9 km2 transect cutting across Shanghai with a moving window. The results showed that the urban landscape pattern of Shanghai was greatly changed when road corridors were merged with urban patches and the variation of patch density would alter when grain size changed. As a linear land use type, road corridors exhibited a different spatial signature comparing with other land use types and distinctive behavior with increasing grain size. Merging road and urban patches resulted in a sharp reduction in patch density, mainly caused by segmentation of roads corridors. The results suggested that grain size around 7.5 m might be optimal for urban landscape analysis. Landscape patch density is significantly correlated with road percent coverage and the most important effect of road corridors in urban landscape is increased habitat fragmentation.

A gradient analysis based on the buffer zones of urban landscape pattern of the constructed area in Guigang City, Guangxi, China

Over the last century urbanization on the landscape has increased and intensified. Urban development has a great impact on the environment at the local, regional and even global levels. As a driving force in global change, the need to understand the dynamics of urban pattern and its change in an accurate and efficient manner is ever more pressing. Based on aerial color infrared photography in 1985 and QuickBird satellite imagery in 2004 and according to the standard for plan and construction of city land use, the landscape of Guigang City was divided into 11 types. In the landscape classification maps, 31 buffer zones, each being 200 m wide, were divided. With the aid of GIS software ArcView 3.2 and landscape pattern analysis software FRAGSTATS 3.3, the landscape spatial patterns of each buffer zone were analyzed at the landscape level and class level. The landscape indices, such as patch size, patch fractal dimension, diversity index and evenness index, were calculated. The results indicated the following: The total area of the residential land and the communal land in 2004 covered 46.3% of the entire constructed area of Guigang City and the sum of the patch number of the two patch types occupied about 39.7% of the total patch number, while the percentages were respectively 48.2% and 45.4% in 1985. This showed that the mosaic landscape with the residential land and communal facilities land became increasingly unclear following urban development and landscape diversity. Based on the gradient analysis with the landscape-level index and the class-level index, there were two business and finance centers in the constructed area. One was located in the urban center with a range of 0.8 km; the other was from the 10 th to the 16 th zone. In each buffer zone, the mean patch size was larger and the landscape shape was more regular in 2004 than in 1985. Furthermore, the Shannon diversity index of each buffer zone rose in 2004 with patch richness and evenness increasing. The landscape index computed for the main landscape types (communal facilities land, industrial estate land, residential land and farmland) in the middle of the buffer zones clearly indicated the changes taking place in urbanization. The patch size and the patch number of industrial estate land and farmland also pointed to these changes, while communal facilities land and residential land assumed another similar tendency towards changes. In each gradient zone, industrial estate land had the most complex shape, the lowest area percentage of each zone and the biggest mean patch size, whereas communal facilities land and residential land were opposite to industrial estate land. Farmland had a steady percentage along the buffer zone and its continuous distribution had an important impact on the urban eco-environment. The question of how to relate the pattern of changing characteristics along the buffer zone to the urban ecological process and urban ecological planning remains to be studied further in the future.

Spectral Mixture Analysis of the Urban Landscape in Indianapolis with Landsat ETM+ Imagery

This paper examines characteristics of urban land-use and land-cover (LULC) classes using spectral mixture analysis (SMA), and develops a conceptual model for characterizing urban LULC patterns. A Landsat Enhanced Thematic Mapper Plus (ETM+) image of Indianapolis City was used in this research and a minimum noise fraction (MNF) transform was employed to convert the ETM+ image into principal components. Five image endmembers (shade, green vegetation, impervious surface, dry soil, and dark soil) were selected, and an unconstrained least-squares solution was used to un-mix the MNF components into fraction images. Different combinations of three or four endmembers were evaluated. The best fraction images were chosen to classify LULC classes based on a hybrid procedure that combined maximum-likelihood and decision-tree algorithms. The results indicate that the SMAbased approach significantly improved classification accuracy as compared to the maximum-likelihood classifier. The fraction images were found to be effective for characterizing the urban landscape patterns.

RETRACTED: A GIS-based gradient analysis of urban landscape pattern of Shanghai metropolitan area, China

This article has been retracted by the Editor-in- Chief. Reason: This article substantially copies an article by Matthew Luck and Jianguo Wu, “A gradient analysis of urban landscape pattern: a case study from the Phoenix metropolitan region, Arizona, USA” published in Landscape Ecology 17 (4), pp 327–339, 2002. The authors Zhang et al. have indicated in response to a query from the editor that this does not amount to plagiarism because the Luck article was cited in their paper In my view, the amount copied exceeds the usual purpose of citation (to refer to prior relevant work) and amounts to plagiarism.

New urbanism: A new approach to the way America builds

New Urbanism has been characterized as the most important phenomenon to emerge in American architecture and planning since the Modernist movement. Like any movement promoting ideas that challenge long standing practices, New Urbanism has received its share of criticism. This article focuses on the positive aspects of these movements. It provides an overview of the movement and looks into the lessons that could be learned from the application of its ideas to the design and development of cities. Illustrative of many New Urbanism ideas are the efforts undertaken in Europe during the last decade of the twentieth century. The charter outlines a new vision of the spatial and physical form of the contemporary built environment promoted by New Urbanism and defines the principles and development policies that support that vision. Then, the Charter refers to regions as "fundamental economic unitas of the contemporary world" and calls for coordination of public policies, physical planning, and economic strategies to deal with this new reality. New Urbanism brings to fore the importance of an integrated approach to rectifying the problems of urban growth and to bring about change to the unsustainable pattern of the current urban landscape. It, also, asserts that the process for effecting changes in the urban structure and public policies should be based on developing close partnerships and cooperation among various disciplines, interest groups, and citizens. There is, also, an idea on Reaffirmation of the Traditional Urbanism principles that have guided design of cities for centuries. New Urbanism, of course, does not offer solutions to all ills of the American built environment, however, it has inspired significant changes in the approaches to planning and development.

A gradient analysis of urban landscape pattern: a case study from the Phoenix metropolitan region, Arizona, USA

Urbanization is arguably the most dramatic form of land transformation that profoundly influences biological diversity and human life. Quantifying landscape pattern and its change is essential for the monitoring and assessment of ecological consequences of urbanization. Combining gradient analysis with landscape metrics, we attempted to quantify the spatial pattern of urbanization in the Phoenix metropolitan area, Arizona, USA. Several landscape metrics were computed along a 165 km long and 15 km wide transect with a moving window. The research was designed to address four research questions: How do different land use types change with distance away from the urban center? Do different land use types have their own unique spatial signatures? Can urbanization gradients be detected using landscape pattern analysis? How do the urban gradients differ among landscape metrics? The answers to these questions were generally affirmative and informative. The results showed that the spatial pattern of urbanization could be reliably quantified using landscape metrics with a gradient analysis approach, and the location of the urbanization center could be identified precisely and consistently with multiple indices. Different land use types exhibited distinctive, but not necessarily unique, spatial signatures that were dependent on specific landscape metrics. The changes in landscape pattern along the transect have important ecological implications, and quantifying the urbanization gradient, as illustrated in this paper, is an important first step to linking pattern with processes in urban ecological studies.