玉峰集水區颱風事件河川流量和懸移質濃度關係之研究

The Relationship between Discharge and Suspended Sediment Concentration at Typhoon Events in Yu-Feng Catchment

朱怡亭(Yi-Ting Chu) ； 徐美玲(Mei-Ling Hsu)

《地理學報》 49期 (2007/09) Pp. 1-22

https://doi.org/10.6161/jgs.2007.49.01

摘要

本研究搜集颱風期間的短時距懸移質樣本，分析石門水庫上游玉峰集水區2002和2006年共7場颱風流量與懸移質濃度的關係。研究發現，單場颱風流量與懸移質濃度關係與臨前雨量、降雨特性和颱風發生時間有關，發生在颱風季節初期者遲滯效應不明顯，但出現在其他颱風之後者，其懸移質濃度與流量的關係則呈現順時針遲滯圈形態，顯示颱風事件末期輸砂供應不足的現象。此外，暴雨中心與主要崩塌地的相對關係，也與單場事件的懸移質濃度變化趨勢相吻合。
透過集水區崩塌地變遷分析，2002至2006年這段期間崩塌地面積增加了2倍，且大多集中在河道附近，使2006年的懸移質濃度則較2002年增加了13.1-15.6倍。兩年的懸移質濃度在流量的上升翼和下降翼反應不一，2006年上升翼濃度增加速率比2002年快，下降翼減少速率則比2002年緩慢，顯示2006年懸移質供應量較充足，突顯集水區崩塌地變遷對河川懸移質濃度變化的影響力。

關鍵字

颱風 ； 崩塌 ； 遲滯圈 ； 懸移質 ； 暴雨中心

並列摘要

Hourly water samples collected in the Yu-Feng catchment, an upper montane catchment of Shihmen Reservoir, from seven typhoon events in 2002 and 2006 were used to construct hydrographs and time series of sediment concentration. It was found that the relationship between discharge and sediment concentration of an event was related to the antecedent rainfall, rainfall characteristics, and the timing of the events in the typhoon season. The hysteresis effect was less obvious when typhoons occurred in the beginning of the typhoon season. In contrast, typhoons which took place right after others showed clockwise hysteretic loops, indicating signs of sediment depletion in the catchment. Comparison of the landslide intensities at the loci of hourly rainfall centers in temporal sequence with the pattern of sediment concentration in the hydrographs verified the importance of landslides in affecting the fluvial sediment concentration.
Comparisons of landslides records showed that landslide area increased two times from 2002 to 2006. During the same time period, the sediment concentration level from the typhoon events increased 13.1-15.6 times. Sediment concentration in the rising limbs of those 2006 hydrographs increased at much higher rates than those of 2002 hydrographs. In contrast, sediment concentration in the falling limbs of 2006 hydrographs decreased at much slower rates than those of 2002 hydrographs. These phenomena testified the existence of abundant sediment supply in 2006.

並列關鍵字

typhoon ； landslide ； hysteretic loop ； suspended sediment ； rainfall center

參考文獻

Asselman, N. E. M.(1999).Suspended sediment dynamics in a large drainage basin: the River Rhine.Hydrological Process.13,1437-1450.

Burt, T. P.,Donohoe, M. A.,Vann, A. R.(1983).The effect of forestry drainage operations on upland sediment yields: the results of a storm-based study.Earth Surface Processes and Landforms.8,339-346.

Dadson, S. J.,Hovius, N.,Chen, H.,Dade, W. B.,Hsieh, M. L.,Willett, S. D.,Ching, H. J.,Horng, M. J.,Chen, M. C.,Stark, C. P.,Lague, D.,Lin, J. C.(2003).Links between erosion, runoff variability and seismicity in the Taiwan orogen.Nature.426,648-651.

Dadson, S. J.,Hovius, N.,Chen, H.,Dade, W. B.,Lin, J. C.,Hsu, M. L.,Lin, C. W.,Horng, M. J.,Chen, C. T.,Milliman, J.,Stark, C. P.(2004).Earthquake-triggered increase in sediment delivery from an active mountain belt.Geology.32,733-736.

Edwards, T. K.,Glysson, G. D.(1970).Techniques of Water-Resources Investigations.Washington, D.C.:United States Geological Survey.