The Assessment of Climate Change and Land-Use Influences on the Runoff of a Typical Coastal Basin in Northern China

Land use and climate change are the two major driving factors of watershed runoff change, and it is of great significance to study the influence of watershed hydrological processes on water resource planning and management. This study takes the Changyang River basin as the study area, builds a SWAT model and explores the applicability of the SWAT model in the basin. Moreover, we combine data on land use and climate change in different periods to construct a variety of scenario models to quantitatively analyze the impacts of different scenarios on runoff. The results show that the R2 and Ensof the model are 0.71 and 0.68 in the calibration period, respectively, and those in the verification period are 0.68 and 0.65, respectively, indicating that the SWAT model has good applicability in simulating the runoff of the Changyang River basin. Under the comprehensive scenario of land use and climate change on runoff, we found that land use and climate change have a certain contribution to the change in runoff. Therefore, the runoff of the basin increased by 0.22 m3/s, in which land-use change caused the runoff in the basin to increase by 0.07 m3/s attributed to the decreased area of arable land and the increased area of urban land in the basin. Moreover, climate change has caused the runoff in the basin to increase by 0.13 m3/s, mainly influenced by the increased precipitation. The results show that climate change has a more significant effect on runoff in the basin.