本研究探討顆粒及水流條件對沖積扇坡度及堆積型態之影響，實驗使用的顆粒為中砂和粗砂，在不同砂量、不同濃度的水砂比進行實驗，藉此觀察沖積扇的平面堆積形態變化與時間歷程以及掃描最終縱剖面。實驗顆粒由桶倉儲存槽經由渠道沖積於平台上，觀察乾砂顆粒在平台上之沖積輪廓、時間歷程以及利用2D-LiDAR掃描最終縱剖面之結果，並討論坡度之關係。改變不同的水砂比，對於濕砂之沖積或堆積造成什麼影響，討論濕砂之沖積輪廓、時間歷程以及掃描最終縱剖面之結果，從扇面之歷程可知，前期發展縱方向大於側方向；而剖面分析中，水砂比小時，曲線呈現下凹形，水砂比大時，曲線呈現上凸形。探討不同水砂比與最大沖積距離之影響，從結果可知水砂比增加會使最大沖積距離加大及坡度變緩。在水砂比大之情況下，扇面影像分析所觀察到的脫離改道和渠道化現象。

The effects of particle and water flow conditions on the surface slope and deposition patterns of alluvial fans are experimentally explored in this study. The particles used in this study include both medium sand and coarse sand, under the condition of varying discharges of water and sediment. The fan shapes at different time steps were measured by a 2D-LiDAR and compared with pictures taken from cameras. The longitudinal progradation at the earlier stage is faster than that in the lateral direction. Regarding the longitudinal profile, the curve will be concave or convex for the water-sediment ratios are small or large, respectively. The increase of water-sediment ratios will enhance the maximum alluvial distance and reduce the corresponding surface slope. In the case of a large water-sediment ratios, the phenomena of avulsion and channelization on the fan surface were observed.

[1] 王俊凱 (2017)，「不同水砂比之顆粒流對於渠道回淤及沖積扇堆積型態之影響」，碩士論文，國立中央大學土木工程研究所，中壢。
[2] 陳瑞遠 (2016)，「不同水砂比及渠道坡度對沖積扇型態之影響」，碩士論文，國立中央大學土木工程研究所，中壢。
[3] 吳侑謙 (2015)，「顆粒特性及水流條件對顆粒體運動及淤積型態之實驗研究」，碩士論文，國立中央大學土木工程研究所，中壢。
[4] 曾文毅 (2014)，「不同輸砂濃度及基準水面條件下之沖積扇形態分析」，碩士論文，國立中央大學土木工程研究所，中壢。
[5] 吳俊銓 (2012)，「山洪濁流形成沖積扇之實驗研究」，碩士論文，國立中央大學土木工程研究所，中壢。
[6] 孫稜翔 (2011)，「八卦臺地山麓沖積扇型態之研究」，地理學報，第六十一期:81-104.
[7] 詹錢登 (2000)，「土石流概論」，科技圖書股份有限公司，台北。
[8] 蔡元芳 (1999)，「土石流扇狀地形狀特性之研究」，碩士論文，國立成功大學水利及海洋工程研究所，台南。
[9] Asif Khan M., Haneef M., Khan A.S., Tahirkheli T. (2013), “Debris-flow hazards on tributary junction fans, Chitral, Hindu Kush Range, northern Pakistan”, Journal of Asian Earth Sciences, Vol. 62, 720-733.
[10] Bull W.B. (1997), “Discontinuous ephemeral streams”, Geomorphology, Vol. 19, 227-276.
[11] De Haas T., Berg W.V.D., Braat L., Kleinhans M.G. (2016), “Autogenic avulsion, channelization and backfilling dynamics of debris-flow fans”, Journal of International Association of Sedimentologists, 1596-1619.
[12] De Haas T., Braat L., Leuven J.R.F.W., Lokhorst L.R., Kleinhans M.G. (2015), “Effects of debris flow composition on runout, depositional
mechanisms, and deposit morphology in laboratory experiments”, Journal of Geophysical Research Earth Surface, 10.1002, JF003525.
[13] De Haas T., Woerkom T.V. (2016) , “Bed scour by debris flows: experimental investigation of effects of debris-flow composition”, Earth Surface Processes and Landforms, 10.1002/esp.3963.
[14] Delorme P., Voller V., Paola C., Devauchelle O., Lajeunesse E., Barrier L., Métivier F. (2017), “Self-similar growth of a bimodal laboratory fan”, Earth Surface Dynamics, 5, 239-252.
[15] Guerit L., Métivier F., Devauchelle O., Lajeunesse E., Barrier L. (2014), “Laboratory alluvial fans in one dimension”, Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics, Vol. 90, 022203.
[16] Larkin Z.T., Tooth S., Ralph T.J., Duller G.A.T., Mccarthy T., Keen-Zebert A., Humphries M.S. (2017), “Timescales, mechanisms, and controls of incisional avulsions in floodplain wetlands: Insights from the Tshwane River, semiarid South Africa”, Geomorphology, Vol. 283, 158-172.
[17] Levy J.S., Head J.W., Dickson J.L., Fassett C.I., Morgan G.A., Schon S.C. (2009), “Identification of gully debris flow deposits in Protonilus Mensae, Mars: Characterization of a water-bearing, energetic gully-forming process”, Earth and Planetary Science Letters, 09953, 10.1016.
[18] Nicholas A.P., Clarke L., Quine T.A. (2009), “A numerical modelling and experimental study of flow width dynamics on alluvial fans”, Earth Surf. Process. Landforms, Vol. 34, 1985-1993.
[19] Procter J.N., Cronin S.J., Zernack A.V., Lube G., Stewart R.B., Nemeth K., Keys H. (2014), “Debris flow evolution and the activation of an explosive hydrothermal system; Te Maari, Tongariro, New Zealand”, Journal of Volcanology and Geothermal Research, Volgeo-05363; No of Pages 14.
[20] Reitz M.D., Jerolmack D.J. (2012), “Experimental alluvial fan evolution: Channel dynamics,slope controls, and shoreline growth”, Journal of Geophysical Research, Vol. 117, F02021.
[21] Shahram Bahrami. (2012), “Morphotectonic evolution of triangular facets and wine-glass valleys in the Noakoh anticline, Zagros, Iran: Implications for active tectonics”, Geomorphology, Vol. 159-160, 37-49.
[22] Williams R.M.E., Zimbelman J.R., Johnston A.K. (2006), “Aspects of alluvial fan shape indicative of formation process: A case study in southwestern California with application to Mojave Crater fans on Mars”, Geophysical Research Letters, Vol. 33, L10201.