The digital elevation model(DEM)is a type of model that has been widely used in terrain analysis and hydrological modeling.DEM resolution influences the hydrological and geomorphologic features of delineated catchments and consequently affects hydrological simulations.This study investigated the impacts of DEM resolution on the performance of the XAJ-GIUH hydrological model,a model coupling the widely used Xinanjiang(XAJ)hydrological model with the geomorphologic instantaneous unit hydrograph(GIUH),in flood simulations in small and medium-sized catchments.To test the model performance,the model parameters were calibrated at a fine DEM resolution(30 m)and then directly transferred to the simulation runs using coarser DEMs.Afterwards,model recalibration was conducted at coarser DEM resolutions.In the simulation runs with the model parameters calibrated at the 30-m resolution,the DEM resolution slightly affected the overall shape of the simulated flood hydrographs but presented a greater impact on the simulated peak discharges in the two study catchments.The XAJ-GIUH model consistently underestimated the peak discharges when the DEM resolution became coarser.The qualified ratio of peak simulations decreased by 35％when the DEM resolution changed from 30 m to 600 m.However,model recalibration produced comparable model per-formances when DEMs with different resolutions were used.This study showed that the impact of DEM resolution on model performance can be mitigated by model recalibration to some extent,if the DEM resolution is not too coarse.

Cheng Yao;Zhi-jia Li;Ke Zhang;Ying-chun Huang;Jing-feng Wang;Satish Bastola

College of Hydrology and Water Resources,Hohai University,Nanjing 210098,China;Yangtze Institute for Conservation and Development,Hohai University,Nanjing 210098,China;State Key Laboratory of Hydrology—Water Resources and Hydraulic Engineering,Hohai University,Nanjing 210098,China;China Meteorological Administration-Hohai University Joint Laboratory for Hydrometeorological Studies,Hohai University,Nanjing 210098,China;School of Civil and Environmental Engineering,Georgia Institute of Technology,Atlanta 30332,USA;Department of Civil and Environmental Engineering,University of New Orleans,New Orleans 70148,USA

水科学与水工程

[1]Cheng Yao;Zhi-jia Li;Ke Zhang;Ying-chun Huang;Jing-feng Wang;Satish Bastola-.Evaluating performance dependency of a geomorphologic instantaneous unit hydrograph-based hydrological model on DEM resolution)[J].水科学与水工程,2022(03):179-188

GIUH,Xinanjiang

Evaluating,performance,dependency,geomorphologic,instantaneous,unit,hydrological,digital,elevation,type,that,has,been,widely,used,terrain,analysis,modeling,influences,features,delineated,catchments,consequently,affects,simulations,This,study,investigated,impacts,XAJ,coupling,flood,small,medium,sized,To,test,parameters,were,calibrated,fine,then,directly,transferred,runs,using,coarser,DEMs,Afterwards,recalibration,was,conducted,resolutions,In,slightly,affected,overall,shape,simulated,hydrographs,but,presented,greater,peak,discharges,two,consistently,underestimated,when,became,qualified,decreased,by,changed,from,However,produced,comparable,formances,different,showed,can,mitigated,some,extent,not,too

0.419112