Suchergebnisse

Global warming is widely regarded as one of the most critical environmental issue in the 21st century. It is known to exacerbate urban heat island effects, a phenomenon that could affect the livability of cities and the lives and comfort of more than half of the world population who are now living in urban areas. The issue on how to mitigate the impacts of this phenomenon and help urban dwellers adapt to it, has been, and continues to be, an important topic in the context of landscape design and urban planning. This study sought to examine the cooling effects of different land cover types from the perspectives of landscape composition and configuration. Landsat-8 OLI/TIRS data was employed to derive both landscape composition and land surface temperature (Figure 1). The objectives of this study are to: (1) detect the spatial pattern of LST in Hangzhou; (2) examine the cooling effect of land cover resources; and (3) understand the correlation between LST and land cover from the perspectives of composition and configuration. Its goal is to reflect on optimal landscape patterns from the perspective of mitigating UHI effects and building more comfortable and livable urban environments. Various spatial and statistical approaches, including urban-rural gradient, grid-based, landscape metrics, and scatter plot, were employed to analyze the derived land cover and land surface temperature (LST) maps. An urban-rural gradient analysis was performed to examine the difference in LST between the urban and rural areas. First, we created a multiple ring buffer zone from the city center of Hangzhou with a distance interval of 1 km. Second, we determined the mean LST and the density of all the land cover types (LCTs) in each ring buffer zone. Finally, the results were plotted along the urban-rural gradient for analysis (Figure 2). The results showed that forest and water were the cooling land cover types in Hangzhou during daytime. The heat core in Hangzhou was situated close to the central business district and the variance in LST in urban and rural recorded at 2.94 °C. The correlation of forest density with mean LST could be detected in both large (690 m) and small (210 m) grids, whereas the correlation of water density with mean LST was only observed in small grids. In general, forest with high aggregation and complex shape behave best in cooling LST while huge and complete water bodies had better cooling effect than scattered water patches. Besides, the minimum cooling scale of forest and water were 150 m and 120 m, respectively. The findings were considered valuable for urban planners to spatially and architecturally build and arrange the cooling land cover resources, eventually to fulfill the Chinese government's new plan of building "livable cities".

Global warming is widely regarded as one of the most critical environmental issue in the 21st century. It is known to exacerbate urban heat island effects, a phenomenon that could affect the livability of cities and the lives and comfort of more than half of the world population who are now living in urban areas. The issue on how to mitigate the impacts of this phenomenon and help urban dwellers adapt to it, has been, and continues to be, an important topic in the context of landscape design and urban planning. This study sought to examine the cooling effects of different land cover types from the perspectives of landscape composition and configuration. Landsat-8 OLI/TIRS data was employed to derive both landscape composition and land surface temperature (Figure 1). The objectives of this study are to: (1) detect the spatial pattern of LST in Hangzhou; (2) examine the cooling effect of land cover resources; and (3) understand the correlation between LST and land cover from the perspectives of composition and configuration. Its goal is to reflect on optimal landscape patterns from the perspective of mitigating UHI effects and building more comfortable and livable urban environments. Various spatial and statistical approaches, including urban-rural gradient, grid-based, landscape metrics, and scatter plot, were employed to analyze the derived land cover and land surface temperature (LST) maps. An urban-rural gradient analysis was performed to examine the difference in LST between the urban and rural areas. First, we created a multiple ring buffer zone from the city center of Hangzhou with a distance interval of 1 km. Second, we determined the mean LST and the density of all the land cover types (LCTs) in each ring buffer zone. Finally, the results were plotted along the urban-rural gradient for analysis (Figure 2). The results showed that forest and water were the cooling land cover types in Hangzhou during daytime. The heat core in Hangzhou was situated close to the central business district and the variance in LST in urban and rural recorded at 2.94 °C. The correlation of forest density with mean LST could be detected in both large (690 m) and small (210 m) grids, whereas the correlation of water density with mean LST was only observed in small grids. In general, forest with high aggregation and complex shape behave best in cooling LST while huge and complete water bodies had better cooling effect than scattered water patches. Besides, the minimum cooling scale of forest and water were 150 m and 120 m, respectively. The findings were considered valuable for urban planners to spatially and architecturally build and arrange the cooling land cover resources, eventually to fulfill the Chinese government's new plan of building "livable cities".

© 2018 Elsevier B.V. The La Mesa Watershed (LMW) is considered as the 'lungs' and the last ecological frontier of the Philippines' National Capital Region, Metro Manila. It is among the many watersheds in the country that suffered from severe deforestation in the past. Nevertheless, over the past few decades, reforestation programs for the LMW have also been initiated. The spatiotemporal monitoring of landscape pattern (composition and configuration) is needed to inform policy and support forward-looking management planning toward landscape sustainability. However, the changes in the landscape pattern of the LMW, including the extent of forest cover loss and gain over the past decades, have not been quantified; hence, this study. We used remote sensing data (Landsat) to classify the land use/land cover of the LMW in 1988, 2002 and 2016. We subsequently used spatial metrics to quantify the changes in the landscape pattern of the watershed. We found that between 1988 and 2002, a period that largely preceded the start of the LMW's major rehabilitation (c. 1999), the watershed had a net forest cover loss of 259 ha. From 2002 to 2016, it had a net forest cover gain of 557 ha. The detected increase in forest cover was supported by the percent tree cover change analysis results based on MODIS data. The deforestation of the LMW resulted in landscape fragmentation as indicated by the decrease in the area of forest and mean forest patch size, and the increase in forest patch density, etc. Forest restoration activities have helped improve the watershed's landscape connectivity as signified by the increase in the area of forest and mean forest patch size, and the decrease in forest patch density, etc. The results also revealed that rapid urbanization has been a major factor driving landscape changes around the LMW, and this requires proactive, forward-looking management planning. Overall, the LMW's case presents some valuable learning experience and insights regarding public-private partnerships toward watershed and forest-related rehabilitation initiatives. On a national scale, the Philippine government has embarked on a massive national greening program. The findings of this study suggest that such efforts could lead to the enhancement of denuded forest areas, if done properly.