Characteristics Of Urban System Research Articles

Wastewater discharges and urban land cover dominate urban hydrology signals across England and Wales

Urbanisation is an important driver of changes in streamflow. These changes are not uniform across catchments due to the diverse nature of water sources, storage, and pathways in urban river systems. While land cover data are typically used in urban hydrology analyses, other characteristics of urban systems (such as water management practices) are poorly quantified which means that urbanisation impacts on streamflow are often difficult to detect and quantify. Here, we assess urban impacts on streamflow dynamics for 711 catchments across England and Wales. We use the CAMELS-GB dataset, which is a large-sample hydrology dataset containing hydro-meteorological timeseries and catchment attributes characterising climate, geology, water management practices and land cover. We quantify urban impacts on a wide range of streamflow dynamics (flow magnitudes, variability, frequency, and duration) using random forest models. We demonstrate that wastewater discharges from sewage treatment plants and urban land cover dominate urban hydrology signals across England and Wales. Wastewater discharges increase low flows and reduce flashiness in urban catchments. In contrast, urban land cover increases flashiness and frequency of medium and high flow events. We highlight the need to move beyond land cover metrics and include other features of urban river systems in hydrological analyses to quantify current and future drivers of urban streamflow.

Cultural Sustainability of US Cities: The Scaling of Non-Profit Arts Footprint with Population

The functional characteristics of urban systems vary predictably with Metropolitan Statistical Area (MSA) population, with certain metrics increasing apace with population (e.g., housing stock), some increasing faster than population (e.g., wealth), and others increasing slower than population (infrastructure elements). Culture has been designated the fourth pillar of sustainability. The population-dependent scaling of operating revenue, work space, and number of employees was investigated for almost 3000 arts organizations in the US, both in aggregate and by arts discipline (music, theater, visual and design arts, dance, and museums). Unlike general measures of creativity, the three measures of economic footprint did not scale supra-linearly with the population of metropolitan areas. Rather, operating revenue scaled linearly (e.g., like amenities), and work space and employee number scaled sub-linearly (e.g., like infrastructure). The cost of living, proxied by housing costs, increased with MSA population, though not as rapidly as did arts organization operating revenue, indicating a degree of uncoupling. The generally higher educational attainment of adults in larger cities, coupled with the growth of the education-dependent arts patronage, suggest a funding focus on less populous (50,000–1,000,000), as well as on under-performing, cities.

URBAN PRIMACY IN URBAN SYSTEM OF DEVELOPING COUNTRIES; ITS CAUSES AND CONSEQUENCES

In the current world, cities have become the main arms of the actuator in the movement of social system of human communities. Nevertheless, urban systems in developing countries, despite the vast potentials, are faced with serious problems such as rapid urbanization, constant migration of rural people to cities, and concentration of population and activities in one or two cities, or, in other words, urban macrocephaly. Despite the primacy or dominance of one city in some developed countries, we do not observe clear negative features of urban primacy; on the other hand, although it is not evident in all countries of the developing world, there are evident features of urban systems in most of these countries. This paper aims to identify and understand the formation of the phenomenon of urban primacy in developing countries. The method of this study is descriptive-analytical and is based on document studies and the results of different urban projects in different area of the developing world and it is responding to these questions about the background and causes of the formation of urban primacy in these countries and its consequences of this phenomenon which led this conclusion that this phenomenon should be analyzed from different dimensions of economic, social, cultural, historical, and political and lastly its causes and consequences should be observed with regard to these dimensions.

Study of Fractal Structure Characteristics of Urban System in Northern Shaanxi

Based on the fractal theory,a quantitative research of the hierarchical structure of urban system, spatial structure and spatial agglomeration characteristics in Northern Shaanxi was made. Working on a major database of Northern Shaanxi non-agricultural population over 2012,traffic map of Shaanxi Province. The results indicate that Yanan and Yulin urban system scale is more concentrated and distribution is more balanced. The Transport accessibility between towns is better. Towns can develop economic cooperation by using infrastructure. The spatial distribution features of urban system in two cities is relatively concentrated. Towns is mainly in the valley along the river which is the main development axes of the urban system. The spatial distribution of urban system in Northern Shaanxi is decreasing from the center to the periphery .The town system presents a cluster distribution.

A method for na-tech risk assessment as supporting tool for land use planning mitigation strategies

Hazardous industrial sites have always represented a threat for the community often provoking major accidents overcoming the boundaries of the plants and affecting the surrounding urban areas. If the industrial sites are located in natural hazard-prone areas, technological accidents may be triggered by natural events, generating so-called na-tech events which may modify and increase the impact and the overall damage in the areas around them. Nevertheless, natural and technological hazards are still treated as two separate issues, and up to now the methods for na-tech risk assessment have been developed mainly for specific natural hazards, generally restricted to some plant typologies and to the area of the plant itself. Based on a review of the current na-tech literature, this article illustrates a risk assessment method as a supporting tool for land use planning strategies aimed at reducing na-tech risk in urban areas. More specifically, a multi attribute decision-making method, combined with fuzzy techniques, has been developed. The method allows planners to take into account, according to different territorial units, all the individual na-tech risk factors, measured through both quantitative and qualitative parameters, while providing them with a na-tech risk index, useful to rank the territorial units and to single out the priority intervention areas. The method is designed to process information generally available about hazardous plants (safety reports), natural hazards (hazard maps) and features of urban systems mainly influencing their exposure and vulnerability to na-tech events (common statistical territorial data). Furthermore, the method implemented into a GIS framework should easily provide planners with comparable maps to figure out the hazard factors and the main territorial features influencing the exposure and vulnerability of urban systems to na-tech events. The method has been tested on a middle-sized Municipality in the Campania Region, identified as 2nd class seismic zone, according to the Ordinance 3274/2003, in which a LPG storage plant, classified as a plant with major accident potential by the Seveso II Directive (art. 9), is located just within the city core.

Urban Systems in General Systems Research

The coincidence of interest in urban problem solving and developments in cybernetics and general systems research and technology is fortunate. However, transfer of knowledge from one field to another is not simple. Urban systems are composed of some elements which require further specifications, and estimation is difficult. Knowledge of parameters and structural relations for urban systems must be transferred to those previously trained in more general systems analysis. The task can be eased by further research in general systems and by developing a team approach to the analysis of urban systems. This paper articulates some of the more general characteristics of urban systems.

Systems Of Urban Places

AbstractA method of “structural chains” is proposed for the analysis of regional urban systems. Each chain is made up of a sequence of numerical elements representing the average population of places at various levels of urban development, from small mining or forestry settlements to large polyfunctional cities of regional or national rank. The absence of a particular category in a region is marked in the chain by a zero. The structural chains of local urban systems can be grouped into tables reflecting the structure of a regional urban system and its local variations. The key characteristics of urban systems reflected by these chains are: the number of elements or levels of development; the number of zeros and their position in the chain, reflecting the degree of development of the urban hierarchy; and the height of the regional tables (number of horizontal rows), representing the number of local urban structures. The method is tested and illustrated by the urban systems of the Dnieper-Donets and Black S...