Impact of urbanization on baseflow characteristics in the central catchment of North China Plain, China

The Dawenhe River and Xiaoqinghe River Basins (116°21′–118°41′E, 35°43′–37°15′N) in the center of the North China Plain (NCP), China. To quantitatively assess the influence of urbanization (two indicators including Impervious Surface Percentage (ISP) and Average Night Light Index (ANLI)) on baseflow hydrological behavior (nine baseflow signatures), this study selects the typical urbanized catchment (nine sub-catchments) within the central NCP, where the baseflow was estimated from the total daily streamflow from 2006 to 2016. Findings show that: (i) Baseflow signatures had a notable spatial variability, in which the magnitude baseflow signatures (Qb10, Qb25, Qb50, Qb90), Baseflow Index (BFI), Concavity Index (CI), and Slope of the baseflow duration curve (SBDC) demonstrated greater values in the north versus the south. (ii) Both ISP and ANLI exhibited an upward trend over time with some fluctuations (R2 > 0.65, p