Urbanization affects runoff processes and sediment transport, but the magnitude of the impacts remains poorly understood. Different spatial patterns of pervious and impervious surfaces influence flow and sediment connectivity between hillslopes and stream networks. Following years of research on the peri-urbanizing Ribeira dos Covões catchment in Portugal, this study uses laboratory rainfall simulation experiments to better assess the impact of soil and pavement patterns on runoff (amount, runoff start and stop times) and sediment transport. Based on urban cores observed in the study catchment, the investigation focused on seven spatial patterns: bare soil (S), 100% pavement (P), and 60% pavement under continuous - C - surface placed upslope (CU) and downslope (CD), and dispersed - D - over the surface with regular (DR), irregular (DI) and linear (DL) distribution. A 1.00 m × 1.00 m flume, 0.05 m deep with a 9° slope, facilitated the experiments. The study used sandy-loam soil (1500 kg m⁻³) with concrete slabs representing pavement. Each experiment comprised a series of four rainfall simulations, each lasting 20 min (50 mm h⁻¹), separated by 30-min intervals, to assess the impact of different initial soil moisture conditions. Results indicate that both spatial pattern and soil moisture drive runoff. Under dry conditions, CD provides runoff that is 7 times faster and about 4% higher than that for CU. Already wet conditions, however, produced 12% more runoff on CU than on CD. The greater runoff arose from faster soil saturation, driven by soil moisture increasing more quickly during the rainfall, as well as upstream runoff from paved surfaces, though runoff took longer to reach the outlet. The dispersed pavement pattern only affected runoff amount, with DL producing the highest coefficients (40–71%) and DI the lowest (25–55%), since longer flow paths increase the opportunities for water infiltration. Additionally, CU yielded 40% more sediment transport than CD, but the three dispersed patterns did not show a significant impact (p > 0.05). The results suggest that appropriate planning can reduce flood hazard and land degradation in urban areas, in particular by using dispersed patterns of sealed surfaces to enhance water infiltration and retention.

城市化影响径流过程和泥沙输送，但影响程度仍然知之甚少。透水和不透水表面的不同空间格局会影响山坡和河流网络之间的水流和泥沙连通性。经过对城市周边城市Ribeira dosCovões的多年研究在葡萄牙的一个集水区，本研究使用实验室降雨模拟实验来更好地评估土壤和路面模式对径流量（径流量的开始和停止时间）和泥沙输送的影响。基于研究集水区中观察到的城市核心，研究集中在七个空间模式上：裸露土壤（S），连续路面100％路面（P）和60％路面-C-地表上坡（CU）和下坡（CD ）并以规则（DR），不规则（DI）和线性（DL）分布分散在表面上。1.00 m×1.00 m的水槽（深0.05 m，倾斜9°）有助于实验。该研究使用砂壤土（1500 kg m ^-3）和混凝土板作为路面。每个实验包括一系列四个降雨模拟，每个模拟持续20分钟（50毫米小时^-1），间隔30分钟，以评估不同初始土壤湿度条件的影响。结果表明，空间格局和土壤水分都驱动径流。在干燥条件下，CD的径流比CU快7倍，高约4％。但是，已经湿润的条件下，CU上的径流比CD上多了12％。更大的径流来自土壤更快的饱和度，这是由于降雨期间土壤水分的增加更快，以及铺面地面的上游径流，尽管径流需要更长的时间才能到达出口。分散的路面模式仅影响径流量，其中DL产生最高的系数（40–71％），DI产生最低的系数（25–55％），因为更长的流路增加了水渗透的机会。此外，铜比CD产生的泥沙输送量高40％，但是这三种分散的模式没有显示出显着影响（p> 0.05）。结果表明，适当的规划可以减少城市地区的洪灾危害和土地退化，特别是通过使用密封面的分散图案来增强水的渗透和滞留。