Review on snowmelt runoff model and variation response mechanism

As a pivotal component of the water cycle, snowmelt runoff exerts significant impacts on water resource distribution and watershed ecosystems. To deepen the understanding of its role in snow hydrology, this study systematically reviewed research advancements in snowmelt runoff modeling and its variation response mechanisms from multiple perspectives: model development and refinement, uncertainty analysis, blowing snow effects, runoff partitioning, topography and vegetation impacts, and climate variation. The following research results are obtained: ① Lumped and distributed models exhibit complementary advantages, the former suitable for large-scale rapid assessments and the latter enabling refined regional simulations. ② Model improvements enhance applicability across diverse regions and climatic conditions, though current refinement strategies predominantly focus on thermal-precipitation phase change mechanisms while inadequately addressing underlying surface heterogeneity. ③ Parameter-induced uncertainty predominates, with research methodologies following a progressive framework of "quantitative analysis-sensitivity ranking-dynamic optimization". Climate-driven parameter uncertainties prove particularly critical, exhibiting distinct geographical variations. ④ Blowing snow alters snowpack input characteristics through sublimation and redistribution mechanisms, though existing theories remain confined to steady-state environments. ⑤ Time series decomposition and isotopic tracer techniques constitute mainstream approaches for runoff partitioning, effectively revealing snowmelt contribution ratios and the delayed effects of influencing factors. ⑥ Among surface characteristics, slope gradient dominates topographic influences, while canopy structure and vegetation types persistently affect snowmelt generation processes. ⑦ RCP scenario simulations consistently demonstrate that temperature elevation will amplify snowmelt′s runoff contribution beyond precipitation effects, projecting future polarization trends. The combined impacts of temperature and precipitation will induce snowmelt runoff fluctuations. Based on the research progress of snowmelt runoff, it is proposed that further in-depth research should be carried out from the aspects of model optimization, blowing snow processes, underlying surface characteristics, and climate change, so as to provide a reference for snow hydrology research and disaster warning.