Automated detection of slum area change in Hyderabad,India using multitemporal satellite imagery

This paper presents an approach to automated identification of slum area change patterns in Hyderabad, India, using multi-year and multi-sensor very high resolution satellite imagery. It relies upon a lacunarity-based slum detection algorithm, combined with Canny- and LSD-based imagery pre-processing routines. This method outputs plausible and spatially explicit slum locations for the whole urban agglomeration of Hyderabad in years 2003 and 2010. The results indicate a considerable growth of area occupied by slums between these years and allow identification of trends in slum development in this urban agglomeration.     

Classifying a high resolution image of an urban area using super-object information

In this study, a multi-scale approach was used for classifying land cover in a high resolution image of an urban area. Pixels and image segments were assigned the spectral, texture, size, and shape information of their super-objects (i.e. the segments that they are located within) from coarser segmentations of the same scene, and this set of super-object information was used as additional input data for image classification. The accuracies of classifications that included super-object variables were compared with the classification accuracies of image segmentations that did not include super-object information. The highest overall accuracy and kappa coefficient achieved without super-object information was 78.11% and 0.727%, respectively. When single pixels or fine-scale image segments were assigned the statistics of their super-objects prior to classification, overall accuracy increased to 84.42% and the kappa coefficient increased to 0.804.     

Analysis of Multitemporal NDVI Data for Crop Yield Forecasting in the Sahel

Abstract

Recent investigations demonstrated that inter‐year NOAA‐AVHRR NDVI variations at the middle of the rainy season can provide information on annual crop yields in Sahelian countries. This line of research is presently extended to the consideration of multitemporal NDVI data for several years (1986-1991) pre‐processed by a proven methodology. The investigation was conducted using NDVI and crop yield data from the sahelian sub‐districts of Niger. The results confirm that geographically standardized NDVI data are efficient for crop yield forecasting, but notable differences exist in this prediction capability depending on the beginning of the season. Late beginnings of the growing (rainy) season (after the end of June) allow optimum forecasting only after mid‐August, while early beginnings lead to anticipate the forecasting capability but also to decrease its accuracy. The importance of these findings in the context of an early warning system is finally discussed.     

Divergent responses to urban transformation projects in Turkey: common sense and state affinity in community mobilization

This article examines the role of state affinity in community struggles against authoritarian, neoliberal urban transformation projects (UTPs) in Turkey. It argues that as neoliberal hegemonic devices, UTPs produce contentious political spaces within which communities negotiate, resist, or comply with state-imposed, pro-market rationales (i.e. common sense). As an alternative to depictions of subaltern communities in mobilization as totally ‘co-opted‘ or ‘victimized‘ in neoliberal renewal or as ’unwilling’ or ’unable’ to produce a collective rights identity, the analysis offers a more complicated picture of community resistance, inactivity, and co-optation. To do this, it adopts a combination of Henri Lefebvre’s theory of production of space and Antonio Gramsci’s theory of hegemony. The analysis is based on the findings from original ethnographic research on two ethnically distinct working-class neighborhoods under UTP threat in Gebze, a satellite city of Istanbul. It compares communities’ affinity with the state-sponsored ideologies (Sunni-Turkish nationalism, neoliberalism) by looking at their ethnic identities and social histories.     

Nonprofits and park equity in Los Angeles: a promising way forward for environmental justice

Disparities in park provision raise environmental and health justice concerns. With public agencies stepping back from providing environmental amenities in increasingly neoliberal urban regimes, nonprofits in the U.S. have assumed a prominent role in the parks and recreation sector. But very few studies have comprehensively assessed whether and how park nonprofits contribute to increasing or closing the equity gap in park provision. Focusing on Los Angeles, I analyze how park nonprofits operate and which demographic groups benefit from new and improved parks supported by nonprofits. Based on interviews with local practitioners and geospatial analyses, I find that nonprofits are leading a park equity movement in Los Angeles and helped address park disparities. To do so, nonprofits built diverse coalitions, leveraged complementary strengths, coalesced with public agencies, and helped generate public funds for parks. These findings show that equity-oriented nonprofits can successfully challenge the unjust outcomes of neoliberal governance.     

Modelling spatial patterns of urban growth in Africa

The population of Africa is predicted to double over the next 40 years, driving exceptionally high urban expansion rates that will induce significant socio-economic, environmental and health changes. In order to prepare for these changes, it is important to better understand urban growth dynamics in Africa and better predict the spatial pattern of rural-urban conversions. Previous work on urban expansion has been carried out at the city level or at the global level with a relatively coarse 5–10 km resolution. The main objective of the present paper was to develop a modelling approach at an intermediate scale in order to identify factors that influence spatial patterns of urban expansion in Africa. Boosted Regression Tree models were developed to predict the spatial pattern of rural-urban conversions in every large African city. Urban change data between circa 1990 and circa 2000 available for 20 large cities across Africa were used as training data. Results showed that the urban land in a 1 km neighbourhood and the accessibility to the city centre were the most influential variables. Results obtained were generally more accurate than results obtained using a distance-based urban expansion model and showed that the spatial pattern of small, compact and fast growing cities were easier to simulate than cities with lower population densities and a lower growth rate. The simulation method developed here will allow the production of spatially detailed urban expansion forecasts for 2020 and 2025 for Africa, data that are increasingly required by global change modellers.     

Urban growth and transport infrastructure interaction in Jeddah between 1980 and 2007

This paper aims to use spatial statistical tools to explore the reciprocal spatial–temporal effects of transport infrastructure and urban growth of Jeddah city, a fast developing polycentric city in Saudi Arabia. Global spatial autocorrelation (Moran's I) and local indicators of spatial association (LISA) are first used to analyze the spatial–temporal clustering of urban growth and transport infrastructure from 1980 to 2007. Then, spatial regression analysis is conducted to investigate the mutual spatial–temporal effects of urban growth and transport infrastructure. Results indicate a significant positive global spatial autocorrelation of all defined variables between 1980 and 2007. LISA results also reveal a constant significant spatial association of transport infrastructure expansion and urban growth variables from 1980 to 2007. The results not only indicate a mutual spatial influence of transport infrastructure and urban growth but also reveal that spatial clustering of transport infrastructure seems to be influenced by other factors. This study shows that transport infrastructure is a constant and strong spatial influencing factor of urban growth in the polycentric urban structure that Jeddah has. Overall, this study demonstrates that exploratory spatial data analysis and spatial regression analysis are able to detect the spatial–temporal mutual effects of transport infrastructure and urban growth. Further studies on the reciprocal relationship between urban growth and transport infrastructure using the study approach for the case of monocentric urban structure cities are necessary and encouraged.     

An Arrow-Cycle Interpretation of the Redevelopment of Stockholm's Central Business District

Danish Journal of Geography 95: 83–91, 1995.

The core of Stockholm's central business district, Lower Norrmalm, underwent a process of total renewal during the post-war period. This study asks if this renewal process may be interpreted as a manifestation of a logic of cyclicity inherent to the economies of regions and nations. First, time series over construction activity are presented for three geographic levels: Stockholm, the inner city and Lower Norrmalm. Then the observed booms and slumps are analyzed in the following contexts: construction activity on the national scale, transportation and urbanization, and finally, economic and spatial restructuring. Developments on Lower Norrmalm during this period seem to have been part of a regional and national building cycle, and were moulded by adaptation to transportation needs and rapid economic restructuring. But the local effects of these forces would have been very different were it not for the mediating and actively orchestrating roles assumed by local institutions.     

“If They Only Knew”: Color Blindness and Universalism in California Alternative Food Institutions

This article takes on the cultural politics of “if they only knew” as it relates to alternative food practice. It draws on surveys and interviews of managers of two kinds of alternative food institutions—farmers' markets and community-supported agriculture—to illustrate the color-blind mentalities and universalizing impulses of alternative food discourse. The ways in which these discourses instantiate whiteness may have a chilling effect on people of color who tend not to participate in these markets proportionate to whites. Minor exclusionary practices may have profound implications for shaping projects of agro-food transformation.     

Water quality management in Singapore: the role of institutions,laws and regulations

Abstract

The paper analyses the legal and regulatory instruments for water quality management that have been set in place in Singapore for control of water pollution, and their evolution since the time of independence in 1965. The role of institutions in the strict implementation of the laws and regulations is also discussed, with special emphasis on the efficient inter-institutional coordination machinery that has made it possible. The analyses show that overall long-term planning and policy-making and a strong political will have been instrumental to give all aspects of water management high priority in the national agenda, thus directly supporting urban, industrial and commercial growth.

Editor Z.W. Kundzewicz