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Based on the remote sensing monitoring results of the monthly scale drought in Sichuan Province from July to August 2000-2015(Lu et al.(2017)), the multi-scale characteristics of drought are studied in such a complex topographical area in this paper. The multi-dimensional analysis of the monthly average drought conditions and its evolution trend are carried out based on two-dimensional wavelet analysis in different topographic and geomorphological areas. The wavelet square difference (WSD) is taken as an index, the larger the wavelet square difference is, the richer the structural information is in the study area at that scale, and the greater the intensity of drought effect is. Through the research, it is found that: 1) The WSD of average annual situation of drought conditions is reaching its maximum in the vertical direction (North-South direction), the second in the horizontal direction (West-East direction), and the smallest in the diagonal direction (Northwest-Southeast direction), reflecting the significant spatial differentiation of the drought along the vertical direction of the region. The dominant factor that leads to this phenomenon is the significant vertical gradient of the vegetations. 2) The number and scope of the dominant scales for the annual average drought conditions in different are different. There are 5 dominant scales in the Eastern Sichuan basin, and the scale of 5 040.75 km2 is the most topographic areas in the macro scales. The severe drought and extraordinarily drought grades are dominated by the meso scale at 187.34, 560.08 km2, which is mainly reflected in Chengdu Plain. For the plateau and basin transition zone, there are 3 dominant scales. The macro scale of 2 194.5 km2 is mainly characterized by moderate drought and has a significant vertical differentiation. The meso scales of 160.51 and 418 km2 correspond to severe or extraordinarily droughts, which are mainly reflected in the city and built-up area. For the western Sichuan plateau, there are 2 dominant scales. The macro scale of 9 487.5 km2 is prominently represented in the diagonal direction as the drought-free area where the evergreen coniferous forest and the mixed forest are interlaced in the central part of Ganzi Tibetan Autonomous Prefecture. The meso scale of 637.82 km2 is prominent in the horizontal and vertical directions in area where grassland and mixed forest distributed along in the northwestern of the Tibetan and Qiang Autonomous Prefecture. 3) The number of dominant scales and the prominent scale characteristics of the drought and evolution trend are inconsistent in 3 major topographical and morphological areas. For the Eastern Sichuan Basin, there are 4 spatial scales in the drought aggravation trend area, and the mesoscale scale is dominant, while the drought mitigation trend area is dominated by the macro scale of 5 023.02 km2. For the plateau and basin transition areas, there are mainly 3 scales in drought-increasing trend areas. The dominant scale is also the meso scale, while the mitigation trend area is more prominent with 3 meso scales. There are 4 dominant scales in the drought-increasing trend area of the western Sichuan Plateau, which is dominated by the macro scale. While the drought mitigation trend area is dominated by the meso scale. 4) Although the dominant scales in the evolution trend of drought in different geomorphological areas are different, they have strong consistency in the causes of these scale characteristics, that is, the dominant scale areas of drought aggravation trend show a kind of vegetation decline, while the area of drought mitigation is presented as the increasing trend of precipitation. [ABSTRACT FROM AUTHOR]