Review of Coupling Atmospheric and Hydrologic Models

Abstract

Research on coupling atmospheric and hydrologic models has become an important issue in both hydrology and meteorology,and also been emphasized by many international scientific programs.Land surface scheme,which plays a crucial role of interface between atmospheric and hydrologic models,is introduced in the coupling process by many researchers.Based on a summary of land surface schemes,research on coupling atmospheric and hydrologic models is reviewed in detail from four aspects according to the methods and purposes of coupling:(1) forcing hydrologic model by atmospheric model outputs directly,(2) strengthening hydrological descriptions in land surface models,(3) setting up land surface model hydrologic model coupled system,and(4) some two-way coupling researches.The usual one-way coupling has its own drawback since the land-surface process is treated independently,which gives rise to inconsistent state variables between atmospheric and hydrologic models.This problem can be avoided if the two models share a same land surface scheme.Several key aspects in the study of such two-way coupling must be faced,including time-spatial scales difference,sub-grid heterogeneity,precipitation simulation accuracy,etc.Remote sensing,satellites,geological information system and four-dimensional variation data assimilation provide robust methods and techniques to resolve the main problems in coupling process.In the future,developing two-way coupling experiments and sensitivity analysis will be needed to investigate the interactions between atmosphere-vegetation-soil-hydrology processes through interdisciplinary researchers,to realize two-way coupled atmospheric-hydrological model system,and to improve the simulation and prediction both for atmospheric and hydrologic models.Such coupled model system can effectively decrease life and financial loss due to hydrological extreme events or climate abnormity,such as floods and draughts.