Please use this identifier to cite or link to this item:
Department of Geography, NTNU
Lanyang area including longitudinal valley and alluvial plain is located between the northern part of Central Range and Snow Mountain. With conspicuous fault scarps and abundant debris supply, alluvial fans are developed well in this area. There are 30 fans with area over 1 ha. each, 13 of them are distributed in the longitudinal valley and the rest are in the peidmont surrounding the alluvial plain. In the longitudinal valley, most of the fans have been undercut to be composit fans. There are 4 steps in the upper valley where as 2 steps in the down valley. The fact of the fan head trench shifting down could reveal that the down cutting rate of stream channel is greater than the uplift rate of mountain area. The cross profile of fan deposition is shaped in lenticular could be resulted from the continul uplift of the mountain area. By product-moment correlation, some fan variables are corretaled closely, such as fan area has a significant relation with width, slope and sorting and roundness of sediments. Based on the discriminant analysis, the stream order, relief ratio, uplift rate, precipitation, hypsometric integral, the distance between valley mouth and intermountain basin areas are the dominating factors to the existence of the fan. By factor analysis, uplift rate, drainage area, relief ratio and stage of fan are the main factors influencing the fan morphology. From the relation between fan and drainage basin, the evolution of the fan can be interpretated by both the equillibrium model and the erosional cycle model.
|Appears in Collections:||地理研究|
Files in This Item:
There are no files associated with this item.
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.