城市不透水面扩张对地表径流量的影响

Impact of urban impervious surface expansion on runoff

城市不透水面的扩张对地表径流量有显著影响。以哈尔滨市松花江沿岸的6个中心城区为例,运用线性光谱分解技术和L-THIA模型,模拟小雨、中雨、大雨和暴雨4种日降雨量情景和枯、丰水年情境下,不同年份由于不透水面的扩张所引起的日径流量和年径流量变化。结果表明:日径流量在小雨情境下所受不透水面的影响最为明显,随着雨量增加,影响显著减小;年径流量在枯水年受不透水面扩张的影响大于丰水年。运用L-THIA模型模拟不透水面扩张导致的径流量变化,所需参数少,操作简单快捷,模拟结果可为城市的排涝减灾、规划管理等提供参考。

The expansion of urban impervious surface has a significant effect on surface runoff .Taking the six central regions along the Songhua River in Harbin as the study area ,the paper used linear spectral decomposition technique and long -term hydrologic impact assessment ( L-THIA ) model to simulate four daily rainfall scenarios such as ligh rain ,moderate rain ,heavy rain and rainstorm .It simulated the im-pact of impervious surface expansion on daily and annual runoff variation .Result indicated that the daily runoff in light rainfall scenario is particularly affected by the impervious surface ,with the increase of rain-fall,the impact is reduced significantly;in term of annual runoff , the impervious surface expansion had more significant impact on dry years than that on wet years .The paper used L -THIA model to simulate the runoff change caused by impervious surface expansion .The method requires a small amount of param-eters.The operation is simple and quick .The result can provide a basis for flood mitigation ,planning and management of urban .