225,297 research outputs found
Caterpillar phenology predicts differences in timing of mountain chickadee breeding in urban and rural habitats
No full textTo ensure the survival of their offspring, birds need to precisely time their reproduction: when offspring have the highest demand for food, food resources should be most abundant. In temperate environments, caterpillars are often a key food source for nestlings, so many insectivorous bird species time their reproduction to correspond to the peak abundance of caterpillars in their habitat. Mountain chickadees (Poecile gambeli) are small songbirds that naturally inhabit coniferous forests, but are also found in urban areas. Reproductive timing of these birds may be altered by urbanization, as mountain chickadees in the city have been shown to breed earlier than those in natural habitat. This study aimed to determine if caterpillar abundance drives reproductive timing of mountain chickadees and if urbanization alters the timing of caterpillar abundance. Birds in both urban and rural habitats were monitored throughout the breeding season. Caterpillar abundance was estimated at each nest location by collecting samples of caterpillar excrement (frass).We found that in both urban and rural habitat, frass mass changed throughout the breeding season, but the date of maximum frass mass occurred about one week earlier in urban habitat. However, in both habitats maximum frass mass occurred when offspring were approximately 11 days old. Our results suggest that mountain chickadees time their reproduction to correspond to caterpillar abundance, and birds in urban environments may be reproducing earlier to correspond with earlier peak caterpillar abundance in the city.Peer reviewedarticlespublishedPoecile gambeliFrassUrbanizationReproductive timingCaterpillarMountain chickade
Me Dominum Habere Lætor! Das Güldene Kleinod Davids : Bey Volckreicher ... Leichen-Bestattung Des ... Herrn M. David Heinrich Linckens, In die 24. Jahr Treu-gewesenen Pfarrers zu Gleina, Welcher den 6. April 1709. ... sanfft und seelig eingeschlaffen, Und den 9. ... begraben worden ; aus dem von ihm selbst-erwehlten Leichen-Text Psalm. XVI, 8-11. erwogen ... und zum Druck übergeben / von M. Joh. Schellern, Pfarrern und Adjuncto zu Drakendorff
No full textEnth. 1 Vorwort von Velntin Rauschelbach und 1 Gedicht von M. LickiusVorlageform des Erscheinungsvermerks: Rudolstadt, druckts Heinrich Urban. - Erscheinungsjahr nach dem Sterbejahr bestimm
Urban ‘tourism exploration space’: the example of Łódź
No full textThe author refers to the concept of ‘tourism space’ published earlier, and confronts this notion with a definition of ‘urban space’, bearing in mind that both these ‘spaces’ are subspaces of general ‘geographical space’. Assuming that each is distinguished on the basis of differing criteria, the author believes that the tourism function which gives rise to ‘tourism space’ can develop within ‘urban space’. Further on, the formulation of a precise definition of urban ‘tourism exploration space’ is focused on, which is understood as a personal space of created in the discovery of a city. The conclusion includes three case studies of urban ‘tourism exploration space’ in Łódź: Bidermann family properties, Piotrkowska courtyards and the ‘Green Ring of Tradition and Culture’
Impacts of urban morphology on sensible heat flux and net radiation exchange
No full textUrban morphology affects the sensible heat flux and net radiation exchange which can alter urban heat mitigation plans. This study first parameterized the geometric effects on the net radiation, and then calculated the net radiation and sensible heat flux in the urban landscape of Hong Kong. Considering that the sensible heat flux is the main heat sink in compact urban areas, this study proposes a Normalized Urban Sensible Heat Mitigation Index (NUSHMI) based on the ratio of the net radiation and sensible heat flux. Overall, there is major difference in the dependence of net radiation and sensible heat flux on geometric parameters. Net radiation Rn, reaches an optimal value, either maximum or minimum depending on the parameters of SVF and a standard deviation of building height σh, at intermediate parameter values, which suggests a guideline relevant to urban design targeting the mitigation of urban climate. Contrariwise, sensible heat flux decreases or increases, again depending on SVF and σh, is being considered, with increasing values of the same parameters. For example, Rn, reaches a minimum value for a Sky View Factor (SVF) between 0.5 and 0.6, while it reaches a maximum value for a standard deviation of building height σh between 20 and 30 m. These two results suggest that radiative forcing, i.e. Rn, can be minimized by urban space with SVF around 0.55 and σh around 25 m. The relationships between sensible heat flux and SVF or σh do not show multiple minima or maxima (as with Rn), with the exception of building density, which could also be applied as a guideline in urban design. The results based on the proposed NUSHMI indicated the NUSHMI reaches the highest values when building density is about 0.7 and building height is about 80 m and when the building height standard deviation within an area is about 10 m to 20 m. These findings revealed how the urban morphology affects the surface heat flux exchange between urban canopy and atmosphere boundary layer, and can help to design an efficient urban landscape towards urban heat mitigation for highly compacted cities, e.g. controlling the building density, height, and the height deviation. This combination of urban geometric parameters identifies an urban configuration maximizing the dissipation of absorbed radiant energy as sensible heat. It should be noted, however, that heat load upon buildings would be reduced at the price of maximizing heat dissipation within the built-up space.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Optical and Laser Remote Sensin
Calculating population density for MOLAND in the Dublin urban area
No full textThe EPA-funded Urban Environment Project seeks to apply MOLAND, a cellular automata based model, to predict a range of urban impacts in the Greater Dublin Region from 2006 onwards. One quantitative requirement,
at least in the input stages of model building, is to establish average population densities for the different residential land use classes because the population must be allocated to cells in these classes. It has a separate output function when actually used within the MOLAND model, relating to the estimation of numbers of people affected by a
particular scenario generated by the model. This working paper explores a series of approaches taken to identify population densities for a number of urban land-use categories. The results are documented against a number of differing spatial approaches to test for precision and applicability. Some suggestions are proposed as to the most effective method to use in developing the model.Other funderEnvironmental Protection Agencyti,ke.kpw6/10/1
Urban and Peri-urban Agriculture in Kyiv (Ukraine): "Crisis Induced Strategy" versus Recreational Resource
No full textFor the study 240 Kyiv households with urban and peri-urban agriculture (UPA) have been surveyed in 2005. Quotas were assigned to four different types of plots. A standardized questionnaire was developed to collect data on crop and animal production, inputs, sales of produce for income, importance of the plot for self-sufficiency, recreation and leisure time. A factor analysis is employed to reduce attitudinal data. Based on factor scores a cluster analysis is conducted to segment the respondents into more homogeneous groups and to show multiple purposes of UPA. Four clusters labeled as “Seekers of leisure activities”, “UPA-dependent growers”, “Recreation-oriented growers” and “Little engaged growers” are created. Multiple purposes of UPA are shown by profiling the clusters due to demographic, socioeconomic and other selected characteristics. The results show that depending on the type of plot the importance of UPA shifts from livelihood necessity to recreational resource or combines both.Urban and peri-urban agriculture, livelihood, Ukraine, Farm Management,
Informality and the Development and Demolition of Urban Villages in the Chinese Peri-urban Area
No full textThe fate of Chinese urban villages (chengzhongcun) has recently attracted both research and policy attention. Two important unaddressed questions are: what are the sources of informality in otherwise orderly Chinese cities; and, will village redevelopment policy eliminate informality in the Chinese city? Reflecting on the long-established study of informal settlements and recent research on informality, it is argued that the informality in China has been created by the dual urban-rural land market and land management system and by an underprovision of migrant housing. The redevelopment of chengzhongcun is an attempt to eliminate this informality and to create more governable spaces through formal land development; but since it fails to tackle the root demand for unregulated living and working space, village redevelopment only leads to the replication of informality in more remote rural villages, in other urban neighbourhoods and, to some extent, in the redeveloped neighbourhoods. © 2012 Urban Studies Journal Limited
Retrieval of Vegetation Indices and Vegetation Fraction in Highly Compact Urban Areas: A 3D Radiative Transfer Approach
No full textVegetation indices, especially the normalized difference vegetation index (NDVI), are widely used in urban vegetation assessments. However, estimating the vegetation abundance in urban scenes using the NDVI has constraints due to the complex spectral signature related to the urban structure, materials and other factors compared to natural ground surfaces. This paper employs the 3D discrete anisotropic radiative transfer (DART) model to simulate the spectro-directional reflectance of synthetic urban scenes with various urban geometries and building materials using a flux-tracking method under shaded and sunlit conditions. The NDVI is calculated using the spectral radiance in the red (0.6545 μm) and near-infrared bands (0.865 μm). The effects of the urban material heterogeneity and 3D structure on the NDVI, and the performance of three NDVI-based fractional vegetation cover (FVC) inversion algorithms, are evaluated. The results show that the effects of the building material heterogeneity on the NDVI are negligible under sunlit conditions but not negligible under shaded conditions. The NDVI value of building components within synthetic scenes is approximately zero. The shaded road exhibits a higher NDVI value in comparison to the illuminated road because of scattering from adjacent pixels. In order to correct the effects of scattering caused by building geometry, the reflectance of the Landsat 8/OLI image is corrected using the sky view factor (SVF) and then used to calculate the FVC. Jilin-1 satellite images with high spatial resolution (0.5 m) are used to extract the vegetation cover and then aggregated to 30 m spatial resolution to calculate the FVC for validation. The results show that the RMSE is up to 0.050 after correction, while the RMSE is 0.169 before correction. This study makes a contribution to the understanding of the effects of the urban 3D structure and material reflectance on the NDVI and provides insights into the retrieval of the FVC in different urban scenes
URBAN DEVELOPMENT PROGRAMMES IN THE CONTEXT OF PUBLIC ADMINISTRATION AND URBAN POLICY
No full textDuring the last decade, in many European countries and cities, area-based Urban Development Programmes have been initiated, in response to major problems of poverty and social exclusion. Urban Development Programmes are usually developed in a complex interplay between different governmental levels, and implemented by a wide variety of public and non-public parties. This paper addresses the organisation of these programmes, concentrating in particular on the form and extent of 'public-public partnership', i.e. on the role that the different levels of the public administration play, both through the administrative system and through policy-making. The 'empirical' basis for the paper consists of case studies, derived from the UGIS project ('Urban Governance, Social Inclusion and Sustainability,' a research project financed by the European Commission, DG RTD). The short analysis makes clear that both the model of public administration, in terms of the extent and form of decentralisation, and the presence (or lack) of a national policy framework determine the extent to which UDPs can be planned, approved and implemented at the local level. One of the main findings is that the central influence over UDPs depends more on the urban policy framework of the central government than on the model of public administration of a country. Countries with strong national (regional) urban policies, sufficient decentralisation of public administration to the municipal level and the use of governance methods at the local level open up possibilities for successful UDPs. Without upper-level urban policy frameworks UDPs might be successful as well, but their replicability and the control over their external effects will not be ensured. Copyright (c) 2005 by the Royal Dutch Geographical Society KNAG.
Urban space diversity in Doha
No full textCities have always been highly differentiated places expressive of heterogeneity, a diversity of activities, entertainment, excitement, and pleasure. They have been and still are the melting pots for formulating and experimenting with new philosophies, and religious and social practices. They produce, reproduce, represent, and convey much of what counts today as culture, knowledge, and politics. Urban spaces within cities are no exception; they are places for the pursuit of freedom, un-oppressed activities and desires, but also ones characterised by power, systematic oppression, domination, exclusion, and segregation. In dealing with these polar qualities, diversity has become one of the new doctrines of city planners, urban designers and architects. It continues to be at the centre of recent urban debates. Little is known, however, about how planned public urban spaces produce social diversity, which aspects of diversity can be planned for, and what can be achieved spontaneously. This article examines some of these ideas within the context of the City of Doha, capital of Qatar
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