Extraction of geomorphic parameters for geomorpho-climatic instantaneous unit hydrograph based on DEM
LIN Jing-Jing-；Bi-Hua-Xin-；Liu-Xin-；Ma-Na
College of Soil and Water Conservation,Beijing Forestry University,National Field Research Station of
Forest Ecosystem,Jixian,Shanxi,100083,Beijing,China
Abstract：Extraction of geomorphic parameters is the foundation of constructing hydrological model,so the precision of extraction of geomorphic parameters affects the accuracy of hydrological model.This paper studied on the method of geomorphic parameters for Geomorpho-Climatic Instantaneous Unit Hydrograph(R-V GIUH) by DEM: dealing with the sink-filling problem of DEM;extracting channel network of different critical support area;analysing on the effects of the critical support area on both the total length and the average slope of the extracted channel network;determining the critical support area for channel development;calculating the geomorphic parameters of watershed for the convergence model of R-V GIUH. The method is applied in Fengjiageduo small watershed(17.98 km<sup>2</sup>).The results showed that the extracted drainage networks are reasonably close to the reality,and Horton's bifurcation ratio(4.608 3),area ratio(2.592 8),length ratio calculated(3.399 9) are in the proper range which is determined by analysing lots of data of nature water systems.The proposed approach removes the subjective decision on the choice of drainage area threshold,and improves exactness of extracting geomorphic parameters.
林靓靓；毕华兴；刘鑫；马娜. 基于DEM的流域地貌气候瞬时单位线地貌参数的提取[J]. 中国水土保持科学, 2007, 5(5): 5-10.
LIN Jing-Jing-；Bi-Hua-Xin-；Liu-Xin-；Ma-Na. Extraction of geomorphic parameters for geomorpho-climatic instantaneous unit hydrograph based on DEM. SSWCC, 2007, 5(5): 5-10.
2007, Vol. 5 
