Constant-slope alluvial fans and source basins in Taiwan
Constant-slope alluvial fans and source basins in Taiwan
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台湾恒坡冲积扇与源盆地
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
Kyoji Saito
中科院分区：
文献类型：
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作者：
Zhou Lin;T. Oguchi;Yue‐Gau Chen;Kyoji Saito
我们研究了台湾冲积扇及其源盆地的地貌特征。虽然其他地方的研究发现，随着盆地面积的增加，冲积扇坡度和盆地坡度会减小，但台湾中央山脉主干上相对较大的扇和源盆地沿着往往具有恒定的平均坡度，分别约为0.9°和32°，盆地面积在80-2900 km 2范围内变化。较小的扇和源盆地，主要是在远离山脉主干的较低地区，有更多不同的坡度。恒坡扇和盆地的存在可能反映了在非常快速的隆起和侵蚀下形成的高度组织化的山坡-河道系统。该系统主要是陡峭的V形山谷，具有相似的山坡角度和一贯的高梯度通道，使有效的沉积物冲洗。这导致了相似的泥沙流量与径流的比率和相似的泥沙颗粒大小，无论流域面积如何，导致冲积扇具有相似的坡度。
We examined morphometric properties of alluvial fans and their source basins in Taiwan. Although studies elsewhere have found a decrease in alluvial-fan slope and basin slope with increasing basin area, the relatively large fans and source basins along the backbone of the Taiwan Central Range tend to have constant mean slopes of approximately 0.9° and 32°, respectively, with basin areas varying over the range 80–2900 km 2 . Smaller fans and source basins, mostly in lower areas away from the backbone of the range, have more varied slopes. The existence of the constant-slope fans and basins may reflect highly organized hillslope-channel systems that have formed under very rapid uplift and erosion. The systems are dominated by steep V-shaped valleys with similar hillslope angles and consistently high-gradient channels that enable efficient sediment flushing. This leads to similar ratios of sediment discharge to runoff and similar sediment grain sizes irrespective of basin area, resulting in alluvial fans with similar slopes.