苟娇娇, 罗明良, 王飞. 影响黄土高原集水面积阈值的地形因子主成分分析[J]. 武汉大学学报 ( 信息科学版), 2017, 42(5): 704-710. DOI: 10.13203/j.whugis20140783
引用本文: 苟娇娇, 罗明良, 王飞. 影响黄土高原集水面积阈值的地形因子主成分分析[J]. 武汉大学学报 ( 信息科学版), 2017, 42(5): 704-710. DOI: 10.13203/j.whugis20140783
GOU Jiaojiao, LUO Mingliang, WANG Fei. Principal Component Analysis for the Terrain Factors of Flow Accumulation Threshold in Loess Plateau[J]. Geomatics and Information Science of Wuhan University, 2017, 42(5): 704-710. DOI: 10.13203/j.whugis20140783
Citation: GOU Jiaojiao, LUO Mingliang, WANG Fei. Principal Component Analysis for the Terrain Factors of Flow Accumulation Threshold in Loess Plateau[J]. Geomatics and Information Science of Wuhan University, 2017, 42(5): 704-710. DOI: 10.13203/j.whugis20140783

影响黄土高原集水面积阈值的地形因子主成分分析

Principal Component Analysis for the Terrain Factors of Flow Accumulation Threshold in Loess Plateau

  • 摘要: 以ASTER GDEM为信息源、22个典型小流域为样区,分析黄土高原集水面积阈值与沟谷密度的关系,利用均值变点法确定最佳阈值,探讨了影响阈值的数字高程模型(digital elevation model,DEM)地形因子主成分。结果表明,集水面积阈值由北向南、自东向西逐步增大,宏观上受黄土高原地貌类型制约,地形因子对其的影响成分归纳为坡面、起伏及高程变异因子。坡面因子的最大值与阈值正相关,坡度>粗糙度>地形曲率>平面曲率>剖面曲率。起伏因子的均值与阈值正相关,起伏度>切割深度。高程变异因子与阈值负相关。三者的主成分贡献率依次为58.754%、18.915%、11.388%,权重为0.527、0.229、-0.569。研究表明,坡面特征是影响黄土沟谷发育的重要因子。

     

    Abstract: This study tris to reveal the relationship between DEM terrain attributes and flow accumulation threshold (FAT) used to extracted gullies in a severe soil erosion region (SSER) of the Loess Plateau of China based on PCA, which will help to pick out the main influence factors in the initiation and development process of Loess gullies. The study region consists of 22 typical watersheds. A series of gully densities produced by different FAT was obtained, and mean change-point was used to identity a best threshold in every watershed. After terrain attributes were calculated based on ArcGIS, a PCA method was used to study the relationship between terrain attributes and FAT. The results show that the FAT increases from north to south, or from east to west in the SSER of Loess Plateau across the entire study area, consistent with the geomorphological types of Loess Plateau. The effective composition of the terrain Factorscan be separated into three groups, namely slope group, relief group, and thw elevation variation group. The maximum value in slope group shows a positive correlation with FAT, and the order can be described as gradient > roughness> terrain curvature> plan curvature > profile curvature. The average value of the relief group also shows a positive correlation to FAT, and the order as relief degree of terrain > dissection index of terrain, while elevation variation group has a negative correlation with FAT. The contribution rates of principal components are 58.754%, 18.915%, 11.388% respectively with weights of 0.527, 0.229, -0.569. The research implies that the slope characteristics are important factors affecting the development of loess gullies.

     

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