崩塌對溪流水化學之影響——以六龜試驗林中寮溪為例

Effects of Landslides on Water Chenistry – A Case Study in Chunglia Stream of Liuquei Experimental Forest

本試驗收集2003-2007年間，六龜試驗林中寮溪上游至下游共4處取樣點之水樣，除了分析乾、濕季溪流水化學之變化，亦探討颱風所造成之崩塌對溪流水化學之影響。分析結果顯示Na、 K、Mg、F、PO、SO、HCO 、總離子濃度於乾季明顯高於濕季，而懸浮值、H、NH、C1、NO、 NO.及TN之濃度於濕季較高。此外，溪水中Na、K、Mg、PO、SO4、HCO，及總離子濃度於4取樣點都在崩塌後有增加之趨勢，上游崩塌面積最大處影響最大，該處總離子濃度較崩塌前增加了 31%，顯示崩塌後由溪流所輸出的營養鹽會增加；但TN於崩塌後則有減少之情形。 The Chunglia stream was studied with regard to water chemistry between dry and wet season and the impact of landslides. Water samples were collected in four sampling sites along Chungliao stream from upstream to downstream of Liouguei Experimental Forest during 2003-2007. Results showed that the concentrations of Na, K, Mg, F, PO4, SO4, HCO3 and total ions in the dry season were significantly higher than in the wet season. On the contrary, the concentrations of suspended solids, H, NH4, Cl, NO2, NO3 and TN were higher in the wet season. In addition, there was an increasing trend in the concentrations of Na, K, Mg, PO4, SO4 and HCO3 after landslides. The strength of the relationship between ion concentration and landslide areas was the highest in the biggest landslide area, up to 31 % increase in ion concentrations. This provided that nutrient outputs were greatly increased after landslides. However, the concentrations of TN in sreaemwater reduced after landslides.