Modeling the Impacts of Urbanization and Open Water Surface on Heavy Convective Rainfall: A Case Study over the Emerging Xiong'an City, China

Abstract

In this study, we examine the impacts of urbanization and open water surface on heavy convective rainfall based on numerical modeling experiments using the Weather Research and Forecasting model. We focus on a severe storm event over the emerging Xiong'an City in northern China. The storm event consists of two episodes and features intense moisture transport and strong large‐scale forcing. A set of Weather Research and Forecasting simulations were implemented to examine the sensitivity of spatiotemporal rainfall variability in and around the urban area to different land use scenarios. Modeling results highlight contrasting roles of open water and urban surface in dictating space‐time organizations of convective rainfall under strong large‐scale forcing. Dynamic perturbation to atmospheric forcing dominates the impacts of open water and urban surface on spatial rainfall distribution during the second storm episode, while urban surface promotes early initiation of convection during the first storm episode through enhanced buoyant energy. Open water surface contributes to convective inhibition through evaporative cooling but can enhance moist convection when the impact of urban surface is also considered. The synergistic effect of open water and urban surface leads to rainfall enhancement both over and in the downwind urban area. Changes in rainfall accumulation with different spatial extents of urban coverage highlight strong dependence of urban‐induced rainfall anomalies on urbanization stages. Our results provide improved understandings on hydrometeorological impacts due to emerging cities in complex physiographic settings and emphasize the importance of atmospheric forcing in urban rainfall modification studies.

Understanding the Impact of Urban Expansion and Lake Shrinkage on Summer Climate and Human Thermal Comfort in a Land‐Water Mosaic Area

“…These include terrain and the proximity to specific land use/land cover types (e.g., lakes, croplands, and deserts). For example, urban expansion occurred near lakes will result in different climate response compared with urban expansion occurred near croplands (Benson‐Lira et al., 2016; Sharma et al., 2016; Su et al., 2021; Xing et al., 2019). This is because water bodies have high heat capacity and low thermal conductivity, and water surface evaporation is an important part of the surface energy budget (Oke, 1987; Yu et al., 2020).…”

“…The presence of water bodies may reduce daytime temperature but raise nighttime temperature, which is called the thermostatic effect (Oke, 1987; Theeuwes et al., 2013). Although previous mesoscale studies highlighted the importance of water bodies in modifying urban climate, these studies were either focused on urban expansion near or around a lake (e.g., Sharma et al., 2016; Su et al., 2021; Xing et al., 2019), or focused merely on lake changes within an indicated urban area (e.g., Theeuwes et al., 2013; Zhou et al., 2016). That is, the coupling relationship between urban expansion and lake changes in a complex physiographic background (i.e., land‐water mosaics), and the combined impacts of urban expansion and lake changes on regional climate remained understudied.…”

High‐Resolution Land Surface Modeling of the Effect of Long‐Term Urbanization on Hydrothermal Changes Over Beijing Metropolitan Area

“…However, above LSMs‐UCMs are widely used to investigate urbanization's impacts on surface energy fluxes, near‐surface temperature (e.g., urban heat island), and precipitation (e.g., storm) at synoptic time scale by coupling with atmospheric models (Giannaros et al., 2018; X. He et al., 2020; Luong et al., 2020; Xing et al., 2019), their applications on analyzing the long‐term terrestrial hydrological and thermal changes over urbanizing regions are still lacking. Although recent works started to investigate the above issue (Georgescu, 2015; Li et al., 2016b; Lin et al., 2016), spatial resolutions used in these works are still too coarse (20–50 km) to provide locally relevant information for a specific city.…”

“…Thus, UCMs are widely chosen by the modeling community, including the Surface Urban Energy and Water balance Scheme (SUEWS; Sun & Grimmond, 2019;Ward et al, 2016), the Community Land Model urban canopy model (CLM-UCM; Oleson & Feddema, 2020;Oleson et al, 2008), LM3-UCM (Li et al, 2016a), Noah-TEB (Meyer et al, 2020), and Noah-SLUCM (Chen et al, 2011). However, above LSMs-UCMs are widely used to investigate urbanization's impacts on surface energy fluxes, near-surface temperature (e.g., urban heat island), and precipitation (e.g., storm) at synoptic time scale by coupling with atmospheric models (Giannaros et al, 2018;Luong et al, 2020;Xing et al, 2019), their applications on analyzing the long-term terrestrial hydrological and thermal changes over urbanizing regions are still lacking. Although recent works started to investigate the above issue (Georgescu, 2015;Li et al, 2016b;Lin et al, 2016), spatial resolutions used in these works are still too coarse (20-50 km) to provide locally relevant information for a specific city.…”

Urbanization Impact on Regional Wind Stilling: A Modeling Study in the Beijing‐Tianjin‐Hebei Region of China

“…Although the impact of urbanization on the regional climate of the BTH region has been investigated extensively in recent years (Miao et al, 2009(Miao et al, , 2011Wang et al, 2012Wang et al, , 2015Wang et al, , 2018Xing et al, 2019;L. Yang et al, 2014;C.-L. Zhang et al, 2009), its associated impact on regional NSWS remains poorly quantified.…”