CAJ | 학술논문

本文利用京津冀地区24个气象站的日降水资料和耦合有单层城市冠层模式（SLUCM）的中尺度数值模式 WRF 的模拟结果，研究了城市地表特征对京津冀地区夏季降水的影响。结果表明，在京津冀城市面积迅速增长的近三十年（1981～2010），该地区大部分站点的降水量都呈现减少的趋势，减少最明显的站点主要集中在京津唐城市区域，其中≥50 mm的降水量减少趋势占总降水量减少趋势的50%以上。城市扩张可能是造成京津冀降水时空格局改变的因素之一。通过对比分析控制试验与敏感性试验的模拟结果，发现城市化引起的地表特征的改变使北京、天津、唐山主要城市地区的降水量和降水频次都有明显减少，而城市群下风向的降水量和降水强度则明显增加和增强，其中50 mm以上等级的降水量变化最为显著，贡献率在60%以上。城市地表特征使北京、天津和唐山地区50 mm以上等级降水量的百分比下降了6%～20%，下风向地区增加了8%。城市地表特征也影响了主要城市和城市群下风向地区降水量的日变化结构，使北京和唐山几乎所有时段的降水量都有所减少，而城市群下风向降水量的增加主要发生在白天。研究发现城市地表特征对深对流的抑制（加强）可能是造成京津冀地区降水减少（增多）的重要原因，而由于城市地表蒸发量的改变引起的潜热通量和对流有效位能的改变则可能是引起深对流变化的重要因素。
본문이용경진기지구24개기상참적일강수자료화우합유단층성시관층모식（SLUCM）적중척도수치모식 WRF 적모의결과，연구료성시지표특정대경진기지구하계강수적영향。결과표명，재경진기성시면적신속증장적근삼십년（1981～2010），해지구대부분참점적강수량도정현감소적추세，감소최명현적참점주요집중재경진당성시구역，기중≥50 mm적강수량감소추세점총강수량감소추세적50%이상。성시확장가능시조성경진기강수시공격국개변적인소지일。통과대비분석공제시험여민감성시험적모의결과，발현성시화인기적지표특정적개변사북경、천진、당산주요성시지구적강수량화강수빈차도유명현감소，이성시군하풍향적강수량화강수강도칙명현증가화증강，기중50 mm이상등급적강수량변화최위현저，공헌솔재60%이상。성시지표특정사북경、천진화당산지구50 mm이상등급강수량적백분비하강료6%～20%，하풍향지구증가료8%。성시지표특정야영향료주요성시화성시군하풍향지구강수량적일변화결구，사북경화당산궤호소유시단적강수량도유소감소，이성시군하풍향강수량적증가주요발생재백천。연구발현성시지표특정대심대류적억제（가강）가능시조성경진기지구강수감소（증다）적중요원인，이유우성시지표증발량적개변인기적잠열통량화대류유효위능적개변칙가능시인기심대류변화적중요인소。
Utilizing daily precipitation data from 24 meteorological stations and results from the Weather Research and Forecasting (WRF) model / Urban Canopy Model (UCM), the impact of urban surface characteristics on summer rainfall in the Beijing–Tianjin–Hebei area was investigated. Results indicated that precipitation at most sites in this region has reduced during the last 30 years, and those sites whose precipitation has reduced the most are mainly centered in the Beijing–Tianjin–Tangshan metropolis. Urbanization is one of the possible factors affecting the precipitation in the Beijing–Tianjin–Hebei area. Comparison of the model results from the control run and sensitivity run indicated that rainfall and rainfall frequency clearly decreased in the Beijing–Tianjin–Tangshan metropolis due to the urban surface. Meanwhile, an increase in rainfall and rainfall intensity was apparent downwind of the urban agglomeration; precipitation above 50 mm changed significantly due to the urban surface, and the contribution to the total could be more than 60%. The percentage of rainfall above 50 mm declined by 6%–20% in the Beijing–Tianjin–Tangshan metropolis, while it increased by 8% downwind. The diurnal structure of rainfall changed due to urbanization: precipitation in Beijing and Tangshan mainly reduced due to urbanization, and the increase downwind occurred mainly in daytime. The findings of this study suggest that the inhibition or enhancement of deep convection, as influenced by changes in latent heat flux and convective available potential energy due to the urban surface, may explain the changes in precipitation.