Geomorphic Development Characteristics and Evolution Process in Luo River Basin,Loess Plateau,China
The morphological characteristics,developmental mechanism and evolutionary process of loess landform always have been the focus and frontier of geoscience research.14 geomorphic factors were selected from slope scale,basin scale and regional scale to construct a comprehensive quantitative parameter system for characterizing the landform development in Luo River Basin,and the factor values and interpolation maps were obtained from 646 small watershed units.Through principal component analysis(PCA),four main factors were obtained,and reflected four spatial patterns of geomorphic morphological,including south-north gradient type,single-center diffusion type,east-west transitional type,and multi-center diffusion type.Combined with geomorphic types and development degree,it is indicated that the characteristics of loess geomorphic relief and vertical erosion reflect the overall geomorphic spatial pattern in Luo River Basin.Under multi-factor influence,the loess geomorphology of Luo River Basin has been continuously headward eroded and expanded downward with water system developed from downstream to upstream,and finally formed the present morphological spatial differentiation pattern.