城市化进程对汛期降水特征的影响——以济南市为例

Impact of urbanization on precipitation characteristics during flood period:case of Jinan city

以往多项研究均表明城市化对降水存在影响,但开展不同城市化阶段对研究区降水影响的研究较少.本文以济南市为研究区,结合1985−2022年土地利用变化与降水数据,探讨了城市化过程对汛期降水特征的影响.本文分析了研究区历史土地利用变化特征,揭示了增雨系数对不透水率的响应规律;定量分析了不透水率对不同等级降水的具体影响.结果表明济南市城市化过程可以分为4个阶段.1995−2000年不透水面面积增速最大,平均为114.77 km^(2)·a^(−1).当不透水率>26%时,增雨系数>1.0,>43%时达到1.10,>60%时将达到1.20.城市化进程随不透水率提高明显促进了小型降雨的发生.

Impact of urbanization on precipitation has been confirmed in multiple studies,but very little is knwon about impact of precipitation at different stages of urbanization in Jinan city,in particular,therefore impact of urbanization on precipitation during flood period was investigated with land use and precipitation data from 1985-2022.The characteristics of land use change was analyzed,response patterns of rainfall to underlying surface imperviousness was explored,effects of imperviousness on different precipitation was studied.Data indicate that the urbanization process in Jinan experienced four stages,with the period from 1995 to 2000 witnessing the most substantial increase in impervious surfaces at an average rate of 114.77 km^(2)·a^(−1).With an imperviousness rate of>26%,rainfall enhancement coefficient became greater than 1.0,but at 1.10 when imperiousness was>43%,and potentially 1.20 when imperiousness rate was>60%.The expansion of impervious surfaces notably increased the occurrence of light rainfall.