Water vapor emissions from urban landscapes in Sakai, Japan
Water vapor emissions from urban landscapes in Sakai, Japan
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DOI：
10.1016/j.jhydrol.2021.126384
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发表时间：
2021-07
影响因子：
6.4
通讯作者：
M. Ueyama;Ayaka Taguchi;Tsugumi Takano
中科院分区：
文献类型：
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作者：
M. Ueyama;Ayaka Taguchi;Tsugumi Takano
城市水汽排放是城市水文和城市气候的重要过程。根据日本大阪酒井市城市中心6年、郊区景观5年、城市公园1年的观测资料，对水汽通量的时空特征进行了评价。与城市附近种植的森林的蒸散量相比，市中心的水蒸气排放量约为市中心的一半，郊区约为四分之一。据估计，市中心的人为水蒸气排放量很高，导致市中心的水蒸气排放量高于郊区。这三个景观的水汽排放受净辐射和地表湿度的控制，其中地表电导率随着降雨事件后的天数而下降。由于城市大气干燥，城市公园的蒸散量与人工林相当，即所谓的绿洲效应。绿色分数解释了年水汽排放量的空间变化。基于线性摄动分析，城市化引起的水汽排放变化可以由人为水汽排放增加和地表电导率降低之间的平衡决定。
Water vapor emissions in urban areas are important processes in urban hydrology and urban climate. We evaluated the spatial and temporal characteristics of water vapor fluxes, based on measurements at an urban center for six years, suburban landscape for five years, and urban park for one year in Sakai, Osaka, Japan. The magnitudes of the water vapor emissions were approximately half for the urban center and one-fourth for the suburb compared with evapotranspiration in a planted forest near the city. Anthropogenic water vapor emissions were estimated to be high in the urban center, resulting in higher water vapor emissions in the urban center than in the suburb. The water vapor emissions at the three landscapes were controlled by net radiation and surface wetness, where surface conductance decreased with days after a rain event. Evapotranspiration of the urban park was comparable to that of the planted forest due to the dry urban atmosphere, known as the oasis effect. The green fraction explained the spatial variation in the annual water vapor emissions. Based on the linear perturbation analysis, the changes in water vapor emissions by urbanization could be determined by a balance between increased anthropogenic water vapor emissions and decreased surface conductance.