2000—2020年南京市土地覆盖变化对地表径流影响研究

The Effect of Land Cover Change on Surface Runoff in Nanjing from 2000 to 2020

土地覆盖信息对研究城市地表径流具有重要意义,而地表径流量可以为城市洪涝灾害风险防范和缓解能力评估提供重要参考。为了探究土地覆盖类型和变化信息对地表径流预测的影响,以南京市为研究区,基于径流曲线模型(Soil Conservation Service Curve Number,SCS-CN)模拟了2000至2020年多种降雨场景下的地表径流量,并分析了不同年份地表径流分布特征,进而评估了土地覆盖及变化对城市潜在洪涝灾害的影响。结果表明,研究区域内地表径流总量逐年增大,洪涝缓解系数呈现下降趋势,一定程度上加剧了城市内涝风险。在所有土地覆盖类型中,不透水面及其变化对地表径流影响最为显著。

Land cover information is of great significance to the study of urban surface runoff,and surface runoff can provide a valuable reference for the evaluation of urban flood management and disaster mitigation capabilities.To explore the influence of land cover type and change information on the prediction of surface runoff,this study takes Nanjing as an example to simulate the surface runoff under various rainfall scenarios from 2000 to 2020 based on the SCS-CN model.Then the distribution characteristics of surface runoff in different years are analyzed,and the impact of land covers and changes on potential flood disasters is evaluated.Finally,the results show that the total surface runoff in the study area increases year by year,and the flood mitigation index shows a downward trend,which aggravates the risk of urban flooding.In addition,among all types of land cover,the impervious surface and its changes have the most significant impact on surface runoff.