Abstract:
There is a typical mountainous area with prominent ecological problems such as geological disasters and soil erosion in Qinling-Bashan Mountains. It will help reveal the genetic mechanism of ecological problems to strengthen the analysis of geomorphic features and morphology. Based on the DEM data, this paper studies the topographic characteristics and geomorphic classification of Qinling-Bashan Mountains by using the methods of domain statistics, mean change point, ISO clustering unsupervised classification and local spatial autocorrelation. The results show: ① The best statistical window of topographic relief is 13×13, the area of which is 1.3689 km
2, and the average topographic relief is 350.61 m; ② The best combination of topographic factors in the study region consists of surface cutting depth, curvature, elevation and its variation coefficient, the cumulative contribution ratio of which is over 92.05%. ③ Spatially, the geomorphic features are high in the West and low in the East, and high in the North and low in the South; besides, the topographic cutting is deep in the middle and West of Qinling Mountains and the East of Bashan Mountains; ④ The spatial clustering of the topographic relief has demonstrated an H-H type of aggregation in Wudu District of the western Qinling-Bashan mountains, and in Langao County and other counties and districts of eastern Bashan Mountains, while an L-L type of aggregation is shown in Yunxian County of the eastern Qinling-Bashan mountains, and in Jiange County and other counties of the southern Bashan Mountains. Due to the influence of geological structure and lithology, the topography is more fragmented in the east of Bashan Mountains and the west of Qinling Mountains, which has an important impact on regional soil erosion and ecological environment.