Potential contributions of climate change and urbanization to precipitation trends across China at national, regional and local scales
Xihui Gu1, Qiang Zhang2,3,4, Vijay P. Singh5, Changqing Song2,3,4, Peng Sun6, Jianfeng Li7
Department of Atmospheric Science, School of Environmental Studies, China University of Geosciences, Wuhan 430074, China;
Key Laboratory of Environmental Change and Natural Disaster, Ministry of Education, Beijing Normal University, Beijing 100875, China;
Faculty of Geographical Science, Academy of Disaster Reduction and Emergency Management, Beijing Normal University, Beijing 100875, China;
State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, China;
Department of Biological and Agricultural Engineering and Zachry Department of Civil Engineering, Texas A&M University, College Station, Texas, USA;
College of Geography and Tourism, Anhui Normal University, Anhui 241000, China.
Department of Geography, Hong Kong Baptist University, Hong Kong, China;
Abstract: Climate change and urbanization collectively influence precipitation changes. However, their separate potential contributions to precipitation changes are not well understood due to their complex interactions. Hence, a “trajectory”-based method was used to separate their potential contributions across national, regional and local scales in China. Precipitation changes in non-urban regions can be regarded as representing the influence of climate change and can serve as a reference for isolating precipitation changes due to urbanization in urban areas. Our results revealed that climate change was the dominant factor for precipitation trends, while urbanization exhibited a relatively weak influence, especially for extreme precipitation at the national scale. At the regional scale, the impacts of urbanization on precipitation became more significant. About 20.2% and -30.6% of positive and negative trends in total precipitation originated from urbanization. At the local scale, the potential contribution of urbanization was strongly correlated with local environmental characteristics. Although there were differences in the potential contributions of climate change and urbanization at national, regional, and local scales, climate change was the dominant factor for precipitation trends and urbanization acted as a regulator to drying or wetting due to precipitation under climate change. In general, urbanization causes a greater impact on total precipitation than on precipitation extremes. Due to this attribution approach is static and broad based and does not render the level of confidence that is needed for scale-aware attribution, future studies are needed to understand the physical mechanisms of impacts of local environment changes on precipitation trends at different geographical locations over China.
Published by International of Journal Climatology, DOI: 10.1002/joc.5997
