Local Climate Zone Study for Sustainable Megacities Development by Using Improved WUDAPT Methodology - A Case Study in Guangzhou

High density urban development in the past has not only changed natural landscape into artificial constructions and pavements, but also brought along many environmental problems like air pollution, urban heat island (UHI) and dust haze, which can affect the public health condition. There are limited applied urban climatic studies in urban planning and development. One of key reasons is there is a missing link between urban development and its corresponding impact on local climatic conditions. The concept of Local Climate Zone scheme has been developed to fit into this gap(1). It introduces a standardized scientific way to describe the land cover and its thermal performance on the UHI. Since 2012, The World Urban Database and Access Portal Tools (WUDAPT) have been developed to call for international efforts and collaborations on world-wide LCZ studies. Its level 0 method can quickly collect urban morphology information and create LCZ maps(2). However, it's time consuming to use WUDAPT to classify cities globally as WUDAPT is designed at city scale. This paper aims to improve the current methodology to classify more cities in a shorter time and also achieve a more accurate result. In this paper, Guangzhou is selected as case study since it has complex urban morphology and can represent as typical megacity in China. The study firstly reviews the concept of LCZ and WUDAPT. Secondly, the level 0 method of WUDAPT is used to initially classify LCZs of Guangzhou. For enhancing the efficiency of the existing WUDAPT, an improved methodology is developed to use WUDAPT to classify a region and extract the cities inside the region. Thirdly, the relevant quality checking work of the two methodologies is also conducted to detect the accuracy of the two methodologies. The improved outputs can be applied to numerical modellings and local planning implementation(3). Because the future trend of urbanization in China is towards megacity development, the lessons learnt from the study can be applied to other megacities and regions for better climatic-spatial planning in future. (C) 2016 Published by Elsevier B.V.