Acta Geodaetica et Cartographica Sinica ›› 2019, Vol. 48 ›› Issue (11): 1404-1414.doi: 10.11947/j.AGCS.2019.20180447

• Photogrammetry and Remote Sensing • Previous Articles     Next Articles

Vector geometry based method for the extraction of slope of aspect by using DEMs

HU Guanghui1,2,3, XIONG Liyang1,2,3, TANG Guoan1,2,3   

  1. 1. School of Geography, Nanjing Normal University, Nanjing 210023, China;
    2. Key Laboratory of Virtual Geographic Environment(Nanjing Normal University), Ministry of Education, Nanjing 210023, China;
    3. Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing 210023, China
  • Received:2018-10-08 Revised:2019-02-25 Online:2019-11-20 Published:2019-11-19
  • Supported by:
    The National Natural Science Foundation of China (Nos. 41930102;41971333;41671389;41601411);The Priority Academic Program Development of Jiangsu Higher Education Institutions

Abstract: Aspect matrix, as the source data for calculating the slope of aspect (SOA), has the characteristic of directionality. Thus, misunderstanding and error would be produced if SOA was calculated by scalar method because its source data has the directional property. On a basis of the mathematical Gaussian surface and 5 m resolution DEM data of different loess landform sample areas, the mathematical vector method is proposed to calculate SOA with a full consideration of directional property of the aspect matrix. In this method, the original aspect matrix has been transformed into the polar coordinate system, and the vector geometric representation of aspect matrix could be achieved. Then the SOA is calculated on a basis of this vector transformed aspect data. In the end, a comparative analysis is conducted among the proposed method and traditional scalar methods. The results show that SOA calculated by the proposed method could effectively avoid the extreme error in the north direction and the inaccuracy when the aspect difference exceeds 180°. Meanwhile, a more reasonable SOA result could be achieved in the other main areas, and a more stable result can be obtained by using our method in different resolution DEMs. The proposed vector geometry method could help to provide a reference for accurate digital terrain analysis, and it is also an important practice to solve problem in DTA by mathematical vector geometry.

Key words: DEM, slope of aspect, aspect, vector geometry method

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