Spatiotemporal Pattern Analysis of Rapid Urban Expansion Using GIS and Remote Sensing

International Journal of Applied Geospatial Research, Vol. 1, Issue 2, 2010

Hyun Kim

“Rapidly growing urban areas tend to reveal distinctive spatial and temporal variations of land use/land cover in a locally urbanized environment. In this article, the author analyzes urban growth phenomena at a local scale by employing Geographic Information Systems, remotely sensed image data from 1984, 1994, and 2004, and landscape shape index. Since spatial patterns of land use/land cover changes in small urban areas are not fully examined by the current GIS-based modeling studies or simulation applications, the major objective of this research is to identify and examine the spatial and temporal dynamics of land use changes of urban growth at a local scale. Analytical results demonstrate that sizes, locations, and shapes of new developments are spatio-temporally associated with their landscape variations and major transportation arteries. The key findings from this study contribute to GIS-based urban growth modeling studies and urban planning practices for local communities.”

Dynamics and Sustainability of Urban Agriculture: Examples from Sub-Saharan Africa

Sustainability Science, Volume 5, Number 1, 2010, 69-78

Pay Drechsel and Stefan Dongus

Urban agriculture can have many different expressions, varying from backyard gardening to poultry and livestock farming. This article focuses on crop production on larger open spaces in cities of sub-Saharan Africa (SSA) and investigates the sustainability and dynamics of this type of land use, which is common on undeveloped plots particularly in lowlands, such as in inland valleys, or along urban streams or drains. An adapted version of the Framework for Evaluating Sustainable Land Management (FESLM) developed by the Food and Agriculture Organization of the United Nations (FAO) was used to assess the sustainability of urban agriculture. As an example for dynamics, the spatio-temporal changes of open-space agriculture in Dar es Salaam, Tanzania, are analyzed for the period from 1992 to 2005, and compared with data from other cities. Crop production on urban open spaces appears as a market-driven, highly productive and profitable phenomenon. However, it is often constrained by tenure insecurity and non-agricultural land demands. Also, the common use of polluted water limits the official support of irrigated urban farming. However, despite these constraints, the phenomenon of urban farming appears persistent and resilient to its changing environment, although individual farmers might have to shift to other sites when their plots are needed for construction. Open-space vegetable production in urban areas is a dynamic, viable and largely sustainable livelihood strategy, especially for poor urban dwellers. Spatio-temporal analysis shows that it is not a short-lived or transitional phenomenon—probably as long as it can maintain its comparative market advantage. However, its informal nature and resulting lack of political recognition need to be addressed.”

Geostatistical Assessment of Pb, Zn and Cd Contamination in Near-Surface Soils of the Urban-Mining Transitional Region of Isfahan, Iran

Pedosphere. 20(5): 568-577.  Available online 3 September 2010.

M. DAYANI and J. MOHAMMADI

“Due to the lack of regulation and environmental education and awareness, Sepahanshahr located in vicinity of Isfahan City, central Iran, is now a rapid growing residential area suffering from the considerable consequences of poorly regulated mining activities operating in its vicinity. A survey was carried out on soil Pb, Zn and Cd concentrations around Sepahanshahr Town to explore the spatial structure of Pb, Zn and Cd distribution and to map their concentrations using geostatistical techniques. 100 near-surface soil samples were collected and analyzed for Pb, Zn and Cd and some related soil physical and chemical variables such as pH, organic matter content, electrical conductivity, and clay, silt and sand contents. The variography results showed a strong spatial dependency in heavy metals concentration due to the dilution effects of natural factors including atmospheric dispersion and precipitation. The almost same range values calculated for both ln-transformed Pb and sand data suggested presence of spatial co-regionalization. However, ln-transformed Zn data showed a shorter spatial dependency among the three tested heavy metals. Kriged maps of all three heavy metals showed a strong gradient of contamination around the three mining sites activating in the area. The results of this study provide insight into identification of the extent and spatial variability of Pb, Zn and Cd pollution in the mining sites and surrounding urban areas.”