| 摘要: |
| 湖陆热力差异激发的局地次级环流是
湖泊缓解周边建成区热环境的驱动机制，明晰
湖风环流特征对优化湖泊降温效应具有重要意
义。本文利用中尺度气象模式WRF/UCM，对
2018年夏季典型气象日武汉城市边界层特征进
行模拟，分析都市发展区湖泊的局地次级湖风
环流发展特征及其降温效应。结果表明：湖风
持续时间受湖泊面积、区位、背景风速影响，湖
泊面积越大湖风持续时间越长，同等规模的城
中湖湖风持续时间长于城郊湖，背景风速增大
时小型城郊湖的湖风率先消失。都市区内极强
热岛与强热岛区域面积随着湖风增强而逐渐减
小，且湖风对湖泊下风向区域的降温强度、范围
均大于上风向地区。分布紧密湖泊产生的湖风环流在边界层高度上连接可形成降温冷链，从而促进近地面湖风降温范围的延展。研究结果可为
与局地次级湖风环流协同的城市降温规划提供参考。 |
| 关键词: 局地次级湖风环流 生消特征 降温效应 武汉市 WRF |
| DOI：10.13791/j.cnki.hsfwest.20220618 |
| 分类号: |
| 基金项目:国家自然科学基金（31670705）；武汉市园林和林业局
科技计划（WHGF2019A01）；中央高校基本科研业务费
专项（2662022YLYJ002） |
|
| Characteristics of Local Secondary Lake Breeze Circulations in Wuhan City and the Cooling Effects Using the Numerical Simulation |
|
WU Changguang,XIE Jing,CHENG Yatian,,CHENG Weijin,LIU Huosheng
|
| Abstract: |
| With the intensification of urbanization, the current ecological environment has been
affected by the deterioration of urban heat islands (UHI) seriously. How to alleviate the UHI
and improve outdoor thermal comfort through nature-based solutions has become a hot topic
for creating a sustainable living environment in the phase of high-quality urban development.
Lake breeze circulations driven by thermal differences between lakes and land surfaces are
the physical drive mechanism for lakes to alleviate UHI effects. Exploring the characteristics
of local secondary lake breeze circulations and their cooling effects will be conducive to
mitigating the UHI problem. However, most studies have focused on the linear relationships
between landscape characteristics and their cooling effects, which is difficult to reflect the
heat exchange process between lakes and their surrounding built environments. Therefore, it
investigated the temporal and spatial characteristics of local secondary lake breeze circulations
between lakes with different sizes and locations and their impacts on the thermal environment
of built-up areas surrounding lakes using the Weather Research and Forecasting model in
Wuhan city in the summer of 2018.
Results showed that lake breezes occurred during the warming period of Wuhan city,
which was 10:00—12:00 local standard time (LST). The formation and disappearance
characteristics of lake breezes were affected by the sizes and locations of lakes and the
background wind speeds. The larger the lake area was, the earlier the lake breezes generated
and lasted longer. The durations of lake breezes in downtown lakes were longer than that of
suburban lakes. When the background wind speed increased, lake breezes disappeared in the
small-sized suburban lakes. The areas of extremely-strong UHI and strong UHI were reduced
with the enhancement of lake breezes. The cooling intensity and cooling range in the downwind
areas of lakes were larger than that of lakes’ upwind areas. The cooling effects of lake breezes
differed between suburban lakes and downtown lakes. Suburban lakes with large sizes could
produce cold air as cold sources and downtown lakes with large sizes could cool the built-up
areas in the direction of lake breezes. The cooling intensities and cooling ranges were affected
by the development intensity of built-up areas in lake surroundings. The cooling intensity oflocal secondary lake breeze circulation can be up to 23 ℃ within 12.5 km when the lake breeze is strongest. Lake breeze circulations were connected
to form cold chains between the close-distributed lakes to expand lake cooling distances.
According to the thermal regulation mechanism of local secondary lake breeze circulations, lakes can be divided into large suburban lakes
(compensating areas), small lakes (diversion points), and large downtown lakes (affecting areas). The protection and management strategies of
various lakes were proposed to maximize lake cooling effects. (1) Protecting the lakes as compensating areas: suburban large lakes should be
protected strictly including Liangzi Lake and Baoxie Lake in the upwind. Urban ventilation corridors for cold air transportation should be reserved;
(2) Guiding the airflow of lakes as diversion points: the cooling pattern of “three points and one line” needs to be built using the connecting effects
of small lakes within the cold chain of local secondary lake breeze circulations and the development intensity between lakes need to be controlled;
(3) Expanding the affecting areas of lakes: there needs to be open spaces such as small lakes in the downtown large lake surroundings through the
integration of water resources and the drainage of lakes. Meanwhile, the ventilation corridors should be reserved in the divergence direction of
lake breezes, so that the cooling effects of lake breezes can further penetrate into the downwind built-up areas. The findings can provide scientific
references for the guidance and management of urban spatial morphology to optimize lake cooling benefits. |
| Key words: Local Secondary Lake Breeze Circulations Formation and Disappearance Characteristics Cooling Effects Wuhan City WRF Model |
