Author
Yuanzhi Zhang
Other affiliations: Chinese Academy of Sciences, Nanjing University of Information Science and Technology
Bio: Yuanzhi Zhang is an academic researcher from The Chinese University of Hong Kong. The author has contributed to research in topics: Synthetic aperture radar & Impervious surface. The author has an hindex of 26, co-authored 111 publications receiving 2003 citations. Previous affiliations of Yuanzhi Zhang include Chinese Academy of Sciences & Nanjing University of Information Science and Technology.
Papers published on a yearly basis
Papers
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TL;DR: The results indicate that the effect of urban heat island in Hong Kong is mainly located in three sub-urban areas, namely, Kowloon Island, the northern Hong Kong Island and Hong Kong International Airport.
Abstract: In this paper, the effect of urban heat island is analyzed using the Landsat TM data and ASTER data in 2005 as a case study in Hong Kong. Two algorithms were applied to retrieve the land surface temperature (LST) distribution from the Landsat TM and ASTER data. The spatial pattern of LST in the study area is retrieved to characterize their local effects on urban heat island. In addition, the correlation between LST and the normalized difference vegetation index (NDVI), the normalized difference build-up index (NDBI) is analyzed to explore the impacts of the green land and the build-up land on the urban heat island by calculating the ecological evaluation index of sub-urban areas. The results indicate that the effect of urban heat island in Hong Kong is mainly located in three sub-urban areas, namely, Kowloon Island, the northern Hong Kong Island and Hong Kong International Airport. The correlation between LST and NDVI, NDBI also indicates that the negative correlation of LST and NDVI suggests that the green land can weaken the effect on urban heat island, while the positive correlation between LST and NDBI means that the built-up land can strengthen the effect of urban heat island in our case study. Although satellite data (e.g., Landsat TM and ASTER thermal bands data) can be applied to examine the distribution of urban heat islands in places such as Hong Kong, the method still needs to be refined with in situ measurements of LST in future studies.
469 citations
TL;DR: The combined use of optical and SAR images by using RF is effective to improve the land cover classification and impervious surface estimation, by reducing the confusions between bright Impervious surface and bare soil and dark impervioussurface and bare land, as well as shaded area and water surface.
189 citations
TL;DR: The experiences and achievements of China’s mangrove conservation efforts presented in this study will facilitate the development of applicable coastal management strategies globally, especially in developing countries.
125 citations
TL;DR: The results showed that the total area of coastal aquaculture ponds in China expanded by 10,463 km2, with the largest gain occurring from 1990 to 2000, and the coastal provinces of Guangdong, Shandong, Jiangsu, Liaoning, and Hebei had significant increases of aquacultural ponds areas.
117 citations
TL;DR: This study aims to conduct a comprehensive comparison between these two data sources and between different methods for mapping ISA and indicates that SVM should be a better choice for ISA estimation using Landsat ETM+ images, while ANN turns out to be more sensitive to the confusion between dry soils and bright impervious surfaces.
77 citations
Cited by
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Journal Article•
TL;DR: In this article, the authors present a document, redatto, voted and pubblicato by the Ipcc -Comitato intergovernativo sui cambiamenti climatici - illustra la sintesi delle ricerche svolte su questo tema rilevante.
Abstract: Cause, conseguenze e strategie di mitigazione Proponiamo il primo di una serie di articoli in cui affronteremo l’attuale problema dei mutamenti climatici. Presentiamo il documento redatto, votato e pubblicato dall’Ipcc - Comitato intergovernativo sui cambiamenti climatici - che illustra la sintesi delle ricerche svolte su questo tema rilevante.
4,187 citations
1,327 citations
674 citations
Posted Content•
595 citations
11 May 2010
TL;DR: It is shown that, although Tibetan plateau heating locally enhances rainfall along its southern edge in an atmospheric model, the large-scale South Asian summer monsoon circulation is otherwise unaffected by removal of the plateau, provided that the narrow orography of the Himalayas and adjacent mountain ranges is preserved.
Abstract: The Tibetan plateau, like any landmass, emits energy into the atmosphere in the form of dry heat and water vapour, but its mean surface elevation is more than 5 km above sea level. This elevation is widely held to cause the plateau to serve as a heat source that drives the South Asian summer monsoon, potentially coupling uplift of the plateau to climate changes on geologic timescales. Observations of the present climate, however, do not clearly establish the Tibetan plateau as the dominant thermal forcing in the region: peak upper-tropospheric temperatures during boreal summer are located over continental India, south of the plateau. Here we show that, although Tibetan plateau heating locally enhances rainfall along its southern edge in an atmospheric model, the large-scale South Asian summer monsoon circulation is otherwise unaffected by removal of the plateau, provided that the narrow orography of the Himalayas and adjacent mountain ranges is preserved. Additional observational and model results suggest that these mountains produce a strong monsoon by insulating warm, moist air over continental India from the cold and dry extratropics. These results call for both a reinterpretation of how South Asian climate may have responded to orographic uplift, and a re-evaluation of how this climate may respond to modified land surface and radiative forcings in coming decades.
550 citations