Nehls T, Menzel M, Wessolek G
Technische Universität Berlin, Chair for Soil Conservation, Ernst-Reuter-Platz 1, 10587 Berlin, Germany E-mail:
Water Sci Technol. 2015;71(6):862-9. doi: 10.2166/wst.2015.025.
Rainfall partition on paved urban surfaces is governed to a great extent by depression storage. This is especially the case for small rainfall events, which are often ignored in urban hydrology. If storage, infiltration and evaporation (important for urban heat island mitigation), rather than storm water run-off, are of interest, high-resolution simulations with exact values for depression storage capacities are required. Terrestrial laser scanners deliver fast, high-resolution surveys of pavement surface morphology. The depression storage capacity can be quantified from 3D points by generating digital elevation models and applying cut-and-fill algorithms in a geographic information system. The method was validated using a test model. It was possible to quantify depressions with a depth of at least 1.4 × 10(-3) m and a surface of at least 15 × 10(-6) m(2) with an uncertainty below 30%. Applying this method, the depression storage capacities for 11 ideal, typical pavement designs were found to vary from 0.07 to 1.4 mm. Realistic urban pavements must also be surveyed, as cracks and puddles from their use history can have a major impact on the depression storage capacities and thus on infiltration, evaporation and, finally, the annual run-off.
城市铺砌地面的降雨分配在很大程度上受洼地蓄水的控制。对于小降雨事件而言尤其如此，而小降雨事件在城市水文学中常常被忽视。如果关注的是蓄水、入渗和蒸发（对缓解城市热岛效应很重要）而非雨水径流，那么就需要进行高分辨率模拟，并给出精确的洼地蓄水容量值。地面激光扫描仪可对路面表面形态进行快速、高分辨率测量。通过生成数字高程模型并在地理信息系统中应用填挖算法，可从三维点量化洼地蓄水容量。该方法通过一个测试模型进行了验证。能够以低于30%的不确定性量化深度至少为1.4×10⁻³米且面积至少为15×10⁻⁶平方米的洼地。应用该方法发现，11种理想的典型路面设计的洼地蓄水容量在0.07至1.4毫米之间变化。还必须对实际的城市路面进行测量，因为其使用历史产生的裂缝和水坑会对洼地蓄水容量产生重大影响，进而影响入渗、蒸发以及最终的年径流量。
