Search

The diurnal land surface temperature (LST) variation is a primary characteristic of the effects of urbanization. However, no study to date has focused on changes in diurnal LST variation in urban environments. This paper investigates the effects of urbanization on landscape pattern and diurnal LST variation of Taipei City, using MODIS thermal images and SPOT multispectral remote sensing images over the 1994–2010 period. Supervised land-cover classifications were conducted to investigate decadal land-cover changes within the study area. A remote-sensing-based urbanization index was adopted as a quantitative measure of urbanization-induced changes in landscape patterns. Diurnal LST variations were assessed using MODIS Aqua satellite images. We found that the diurnal LST variation increases with the urbanization index, with the adverse effects of urbanization on the diurnal LST variation being more substantial in the earlier stages of urbanization. Increasing diurnal LST variation due to urbanization implies that urbanization is likely to result in a greater increase in urban heat absorption than in thermal inertia. This research provides insightful supporting evidence that, in mitigating UHI effects, measures that can reduce urban heat absorption such as urban parks, community green spaces, green roofs and cool (or permeable) pavements should be given higher priority. [ABSTRACT FROM AUTHOR]

• Equality of ecological exchange is associated with urban land teleconnections (ULT). • Two case studies demonstrated the application of the ULT theory to a regional/local level. • Emergy exchange ratios reveal strong inequalities between Taipei and the two case areas due to ULT. • Assessment of urban sustainability should not neglect thinking of ULT. Urbanization is not only accompanied by local land use change, but also causes land use changes in distant places and affects the socio-ecological systems there. Urban land teleconnections (ULT) was introduced as a conceptual framework to link urbanization and land use changes of distant areas in the past, which have been generally ignored. ULT has also been proposed for use in investigating the equity principle of urban sustainability. The unequal exchange between an urban system and distant areas could become underlying causes that result in land use change in distant areas in the future. This study provides two case studies to demonstrate how land use processes are connected through peri-urbanization of Taipei and its resource inflow areas and the implications of the equality of ecological exchanges are discussed. The first case considers vegetable and fruit products from Changhua, Yunlin, and Chiayi Counties (the Chang-Yun-Chia area) of central and southern Taiwan, and the second case considers cement from Hualien in eastern Taiwan. To implement analysis of ULT, emergy synthesis was used to quantify the flow of materials between Taipei and the distant areas providing raw materials for food and construction and to assess the fairness and equality of the exchange. The results indicate that agricultural products or cement from distant areas tend to have low emergy exchange ratios when sold to Taipei markets. This phenomenon results from the fact that money is paid for human services and not for the work of nature that made the products. The low emergy exchange ratio of agricultural products caused land conversion in the Chang-Yun-Chia area. The low emergy exchange ratio of cement not only hurt the local economy of Hualien, because when it is exchanged more emergy of cement leaves the region than is returned in the buying power of the money received for it. Further inequality results, because the high environmental loading of cement extraction impacts the local Hualien system. Using empirical research on the application of the ULT theory to regional/local levels, the impact of the Taipei Metropolitan Area on the Chang-Yun-Chia and Hualien areas not only verifies the Taipei's ULT phenomenon, but also clarifies the research gaps in the application of ULT theory. [ABSTRACT FROM AUTHOR]