Taher Safarrad, Mehran Mansourinia, Hersh Entezami,
Volume 19, Issue 53 (7-2019)
Abstract
Population growth and urbanization development are the main triggering factors of changes in urban land uses. These, in turn, result in changes in the components of radiation balance. The present study tries to analyze the role of urban land uses in radiation balance by calculating net radiation and its analysis. For this purpose, the Landsat 8 satellite image of 2016 was used. Characteristics of radiation flux including net radiation flux (RN), ground surface albedo (α), incoming longwave radiation (RL↓), incoming shortwave radiation (RS↓), outgoing longwave radiation (RL↑), and ground surface temperature were computed using Sebal algorithm.The values of these components in different land uses (compressed residential, scattered residential, green area and wastelands) were analyzed using one-way analysis of variance (ANOVA) and Tukey’s test. The results of this study showed that the selected land uses have significant differences in the amount of radiation flux, therefore the wastelands are warmer than the residential areas by about 6 oC and the residential areas are warmer than the green areas by about 1.5 oC. The results also indicated that these differences are due to changes in output energy (α and RL↑), and any change in land use over time will ultimately lead to a change in the radiation balance and the temperature of those places, which this temperature increase, is different from the increase of the temperature due to global warming.
Dr Shahrivar Rostaei, Dr Rahim Heydari Chyaneh, Mr Ayoub Zoghi,
Volume 24, Issue 73 (8-2024)
Abstract
bstract
As cities become more physically in structure and demographically wider, the rate of crises is also increasing consequently, and cities become more vulnerable to natural disasters for a variety of reasons, including economic and cultural poverty, fault alignment and non-compliance to regulations of earthquake-related issues. What matters is the level of community's preparedness and the degree of vulnerability of the city and its residents, which can be reduced to the lowest level if properly planned and principle policies are adopted. In this research, considering the high potential of Sanandaj in terms of seismicity and the existence of many faults in the vicinity and around of the city, it is tried to gain an authentic understanding of the subject with identifying the factors affecting the earthquake and combining indicators using the Classification Tree Analysis (CTA) model. The results indicate that a large area of the city is in the category of moderate to high vulnerability.52% is in the middle vulnerability category,16.5% is in the high vulnerability category and 1% of the city is considered to be in the very high vulnerability category, which exactly matches the same marginal, old and densely populated neighborhoods. This situation does not render a proper structure and needs more consideration in prospective development plans.
Keywords: Urban Vulnerability, Earthquake, Classification Tree Analysis, ROC Curve, Sanandaj.
