蘭陽溪上游流域逕流量與輸砂量之趨勢分析

THE TREND ANALYSIS OF RIVER RUNOFF AND SEDIMENT TRANSPORTATION OF LAN-YANG RIVER UPSTREAM

宋健豪(JIAN-HOW SUNG)

《工程環境會刊》 36期 (2017/01) Pp. 16-31

https://doi.org/10.6562/JEE.2016.36.2

摘要

由於臺灣位於板塊聚合帶，因此臺灣地形陡峭、河川湍急，許多研究指出臺灣河川的單位面積輸砂量高於世界之平均值。砂質海岸的變化與河川的輸砂量息息相關，而輸砂量的變化亦受到逕流量影響。因此本文應用趨勢分析探討蘭陽溪上游集水區西元1975 年至西元2014 年之間逕流量與輸砂量的變化趨勢。本研究主要透過M-K(Mann-Kendall)趨勢檢定、距平值探討研究區域內逕流量與輸砂量的變化趨勢，M-K 趨勢檢定Z 值若為正值即代表變化趨勢呈現成長，Z 值若為負值則代表變化趨勢呈現減少。本研究結果顯示逕流量之M-K 趨勢檢定Z 值分別為：年逕流量-0.098、豐水期逕流量-0.246、枯水期逕流量-0.418、最大日逕流量-0.086；距平趨勢顯示年逕流量、豐水期逕流量、最大日逕流量，均呈現上升，枯水期逕流量呈現下降。輸砂量之M-K 趨勢檢定Z 值分別為：年輸砂量0.073、豐水期輸砂量0.024、枯水期輸砂量1.182，最大日輸砂量-0.086；距平趨勢顯示年輸砂量、豐水期輸砂量、最大日輸砂量，均呈現上升，枯水期輸砂量無明顯變化趨勢。

關鍵字

蘭陽溪 ； 輸砂量 ； 逕流量 ； M-K 趨勢分析 ； 距平趨勢 ； 率定曲線

並列摘要

Since Taiwan is located in the plate polymerization zone. Therefore, Taiwan has very steep terrain and rivers are powerful and rapids. Many studies have already shown Taiwan's rivers have more sediment outputs per area than the world average. The change of sandy coast is relating to river sediment transportation. The sediment transportation also relates to river runoff. Therefore, in this article we use trend analysis to investigate the sediment transportation and river runoff of the Lanyang River upstream during 1975 to 2014. In this article, we use Mann-Kendall trend analysis, Anomaly trend analysis and Rating curve to investigate the change of sediment transport and river runoff. The Z value of runoff is annual -0.098, flood season -0.246, dry season -0.418, the largest daily -0.086. The Anomaly data showed the trend of annual runoff, flood season runoff, the largest daily runoff are increasing. The Anomaly data showed the trend of dry season runoff is decreasing. The Z value of sediment transport is annual 0.073, flood season 0.024, dry season 1.182, the largest daily -0.086. The Anomaly data showed the trend of annual sediment transport, flood season sediment transport, the largest daily sediment transport are increasing. The Anomaly data showed the trend of dry season sediment transport has no significant changes.

並列關鍵字

Lanyang River ； Sediment Transportation ； River Runoff ； M-K Trend Analysis ； Anomaly Trend Analysis ； Rating Curve