Response of hydrological regimes to land use change: A case study of the Han River Basin

Comprehensive and systematic research linking land-hydrological correlations is lacking in the study of factors driving watershed runoff variations. It quantitatively analyzes the overall watershed hydrological conditions using the range of variability approach (RVA) and applies the Budyko hypothesis to identify driving factors of annual runoff variations. The study also explores the impact of individual land use types on runoff across various timescales using the SWAT model in conjunction with historical and extreme scenarios in the Han River Basin. Results reveal that following abrupt changes, the Han River Basin experiences negative alterations in its hydrological indices and overall conditions. Among the driving factors, the lower cushion surface has the most significant impact on runoff. At an annual scale, runoff increases by 12.57 and 20.4% for cropland and construction land scenarios, while forest and grassland scenarios lead to decreases of 8.45 and 2.32%, respectively. Runoff sensitivity to land use changes is notably higher in the wet season than in the dry season at the quarterly and monthly scales. This study offers valuable insights into the integrated management of land use and water resources in the Han River Basin.HIGHLIGHTS center dot Using IHA - RVA analysis of watershed hydrological situation changes. center dot Attribution analysis of runoff before and after 1991 is conducted using the Budyko hypothesis.center dot Integrating five distinct land use scenarios, we constructed a SWAT model to quantify the impact of different land use types on runoff.