Fig. 1. Location of 42 study areas in the Loess Plateau of northern Shaanxi

Fig. 2. Convergence network and gully network feature points and lines spatial distribution

Fig. 3. Extraction results of feature points and lines by hydrologic analysis of Nantaizi watershed in Huangling county

Fig. 4. Schematic map of horizontal and vertical proximity indexs

Fig. 5. Comparison map of proximity index and proximity distance

Fig. 6. Watershed structure model map^[31]

Fig. 7. Watershed classification map of Yijun

Fig. 8. Proximity index of external confluence region on watershed scale of four key study areas

Fig. 9. Spatial differentiation of MHPI and MVPI in the Loess Plateau of northern Shaanxi

Fig. 10. Comparison of MHPI and MVPI in the external confluence of the four key sample areas on the Loess Plateau of northern shaanxi

Fig. 11. Mean proximity index variability map of external confluence areas in four key study areas of the Loess Plateau of northern shaanxi