Urban Residential Use Research Articles

Urban residential land expansion and agglomeration in China: a spatial analysis approach

As China has undergone rapid urbanization, the share of land dedicated to urban residential use has increased and changed in space accordingly. The rate at which cities expand their urban footprints, however, is not simply a function of population growth, but rather influenced by a number of factors. This study investigated the spatial pattern of urban residential land (URL) in China and factors that drive the expansion of URL on a national scale. Taking a sample from 345 cities, the study applied spatial autocorrelation and spatial regression analysis for discovering China’s URL changes from 2000 to 2016. The study indicated a continuous growth and obvious spatial agglomeration of URL. These were particularly significant in Eastern regions of China, where the highly agglomerated areas were gradually concentrating and expanding in the Yangtze River Delta region, and the coastal area along Shandong and Hebei provinces over time. This contrasted with a spatial de-agglomeration of URL in Northeastern cities. The study also revealed that the effects of economic agglomeration, residential investment, public infrastructure development and government-planned actions by means of urban construction land planning also play significant roles in influencing URL expansion. Despite complexity of these impacts, policy decision making might look to transform growth-oriented development while promoting sustainable land use and livable residential environment beyond the scale of a city.

Estimación de la demanda de agua para uso residencial urbano usando un modelo discreto-continuo y datos desagregados a nivel de hogar: el caso de la ciudad de Manizales, Colombia

The water demand for urban residential use is estimated for the city of Manizales, Colombia, using a structural model that includes both the discrete choice associated with the consumption block and the continuous choice related to the monthly amount of water consumed. The water demand is econometrically estimated using a unique database for a developing country, which contains data on monthly consumption of water, household size, housing characteristics, weather variables, the marginal price of the respective consumption block and the virtual income for 490 households during the period 1997-2013. The results suggest that the estimated structural model is consistent with utility maximization and seems to be the most appropriate empirical approach to estimate econometrically the water demand for urban residential use. Water demand is inelastic, information that is relevant for policy making and the regulation of water resources in urban areas of Colombia.

Legacies of agriculture and urbanization in labile and stable organic carbon and nitrogen in Sonoran Desert soils

Soils regulate air and water quality by storing large pools of carbon (C) and nitrogen (N). Land management decisions have an enduring influence on the integrity and size of these pools, particularly in the upper soil layers. An important challenge, therefore, is to identify how soil C and N bear the marks of both past and present land use. Several studies have documented that effects of agriculture on soil properties can persist long after agricultural abandonment, but these studies typically examine sites returning to forest or grassland. Fewer have investigated legacies of agricultural land use when formerly agrarian land becomes urban. Urban soil management may be intensive, characterized by modifications in microtopography, vegetation, and nutrient and water inputs. We thus hypothesized that urban residential land use would negate any agrarian signatures in the pool sizes of labile (readily mineralized) soil organic C and N, but that agrarian legacies would persist in pools of stable (not readily mineralized) C and N. We tested this hypothesis in arid central Arizona (USA), where residential development in the Phoenix metropolis occurred on both agrarian and uncultivated desert lands throughout the 20th Century. We used a year‐long incubation to quantify labile and stable organic C and N in soils (to 15.2 cm depth) from desert land, contemporary agrarian land, residential yards that were converted from desert, and yards converted from agrarian land use. Labile N in residential soils may have been independent of historical provenance, consistent with the hypothesis that readily‐mineralized pools converge on a single signature of current (residential) land use. Labile C, stable C, and stable N showed the influence of agrarian history decades after conversion to urban residential use. These agrarian legacies in currently residential soil result from the persistence of past agrarian amendments to soil, and are not artifacts of the preferential cultivation of inherently fertile land. Current residential soil management is further amending soil C and N pools on top of the legacy pools left behind by agriculture. We calculate that the persisting influence of agrarian history on soils is similar in magnitude to contemporary urban residential effects.

Maintaining the carbon–oxygen balance in residential areas: A method proposal for land use planning

The efforts to mitigate CO2, one of the greenhouse gases causing global warming and climate change problems, have an important place in the worldwide agenda. One of the factors that cause CO2 emissions is energy use in residential buildings, hence urban residential use is one of the areas on which mitigation efforts are focused. As land use planning determines the spatial development, density and form of residential areas, it has a direct role in the formation of residential emissions. However, these efforts to mitigate emissions could not yet be integrated with land use planning. It is possible to list the reasons as the mitigation efforts are made either on the building scale (mitigation of residential emissions by technological–architectural solutions) or on a global–regional scale (development of carbon sinks), the focus on transportation sector, and in land use planning, lack of considering the potential of urban green areas to mitigate emissions. By taking into consideration the O2 production potential of green areas, a method proposal for land use planning is developed in this study to maintain the carbon–oxygen balance in residential areas. Depending on the form and density of the residential areas developed in a plan, the necessary size of green areas in such a plan is estimated by the method proposed. The varying emission amounts in different residential areas with diverse housing types, the number of actively used residential units, and local vegetation differences are included in the estimate. Therefore, an estimation method proposal that could be easily used in land use planning and that considers local differences is presented in the paper.

Recent developments in photovoltaics

The photovoltaic market is booming with over 30% per annum compounded growth over the last five years. The government-subsidised urban–residential use of photovoltaics, particularly in Germany and Japan, is driving this sustained growth. Most of the solar cells being supplied to this market are ‘first generation’ devices based on crystalline or multi-crystalline silicon wafers. ‘Second generation’ thin-film solar cells based on amorphous silicon/hydrogen alloys or polycrystalline compound semiconductors are starting to appear on the market in increasing volume. Australian contributions in this area are the thin-film polycrystalline silicon-on-glass technology developed by Pacific Solar and the dye sensitised nanocrystalline titanium cells developed by Sustainable Technologies International. In these thin-film approaches, the major material cost component is usually the glass sheet onto which the film is deposited. After reviewing the present state of development of both cell and application technologies, the likely future development of photovoltaics is outlined.

Land Use Controls and Housing Prices in Korea

This paper analyses the effects of government controls over land supply on housing in the rapidly growing cities of Korea. Whilst Korea's urban population more than doubled in the period 1973-88, urban land for residential use grew by only 65 per cent. The result has been extremely rapid rises in city residential land values, although the more dense use of residential land has offset some of this rise on house prices. A substantial part of the rise in house prices has resulted from the government's tendency to underallocate land to urban residential use, although part of the government's surplus is used to subsidise low-income housing within the same projects.

Housing consolidation and the urban poor: the case of Hagar El Nawateyah, Alexandria

Housing consolidation and the urban poor: the case of Hagar El Nawateyah, Alexandria examines the mechanisms by which agricultural land on Alexandria's periphery is converted into urban residential use and examines the main characteristics of the settlement and its inhabitants. It also gives background information on housing conditions in Egypt.