花蓮位於臺灣東部地區，時常發生颱風水患，因此探討當地水文環境有助於花蓮地區永續經營與管理，本研究主要目的是分析花蓮地區花蓮溪與秀姑巒溪水文頻率。本研究使用 1970 年至 2008年花蓮溪與秀姑巒溪河川流量─河川含砂量資料建立迴歸模式以推測 1970 年至 2008 年花蓮溪花蓮大橋測站、花蓮溪仁壽橋測站、秀姑巒溪瑞穗大橋測站與秀姑巒溪立山測站日平均含砂量，本研究發現花蓮溪花蓮大橋測站百分之一時間日平均流量大於 872 秒立方公尺，花蓮溪仁壽橋測站百分之一時間日平均流量大於 231 秒立方公尺，秀姑巒溪瑞穗大橋測站百分之一時間日平均流量大於 1085秒立方公尺，秀姑巒溪立山測站百分之一時間日平均流量大於 185 秒立方公尺，花蓮溪花蓮大橋測站百分之一時間日輸砂量大於 359 公噸/平方公里，花蓮溪仁壽橋測站百分之一時間日輸砂量大於 291 公噸/平方公里，秀姑巒溪瑞穗大橋測站百分之一時間日輸砂量大於 271公噸/平方公里，秀姑巒溪立山測站百分之一時間日輸砂量大於 172公噸/平方公里。花蓮溪花蓮大橋測站當河川流量累積 10%，河川輸砂量累積達 64%，花蓮溪仁壽橋測站當河川流量累積 10%，河川輸砂量累積達 52%，秀姑巒溪瑞穗大橋測站當河川流量累積 10%，河川輸砂量累積達 55%，秀姑巒溪立山測站當河川流量累積 10%，河川輸砂量累積達 55%。花蓮溪與秀姑巒溪河川流量與河川輸砂量頻率分析結果可供相關單位參考，期望有助於花蓮地區水文環境永續經營與管理。

Hua Lien is located in the eastern area of Taiwan. Typhoons and floods often occur in the Hua lien area. Therefore, to examine hydrological environments of this area is helpful to the sustainable development and management of the Hua Lien area. The aim of this study is to do frequency analysis on the hydrological data of Hua Lien Creek and Hsiu Ku Luan Creek in the Hua Lien area. This study uses the rating equations to estimate daily average sediment content from daily mean discharge of the Hua Lien Creek and Hsiu Ku Luan Creek in the period of 1970 to 2008. Results show that at the Hua Lien Bridge station daily mean discharge is larger than 872 cms in 1% of the period. At the Jen Shou Bridge station daily mean discharge is larger than 231 cms in 1% of the period. At the Jui Sui Bridge station daily mean discharge is larger than 1085 cms in 1% of the period. At the Li Shan station daily mean discharge is larger than 185 cms in 1% of the period. Results also show that at the Hua Lien Bridge station daily suspended load is larger than 359 tons/km2 in 1% of the period. At the Jen Shou Bridge station daily suspended load is larger than 291 tons/km2 in 1% of the period. At the Jui Sui Bridge station daily suspended load is larger than 271 tons/km2 in 1% of the period. At the Li Shan station daily suspended load is larger than 172 tons/km2 in 1% of the period. Results also show that at the Hua Lien Bridge station suspended load cumulated 64% when stream discharge cumulated 10%. At the Jen Shou Bridge station suspended load cumulated 52% when stream discharge cumulated 10%. At the Jui Sui Bridge station suspended load cumulated 55% when stream discharge cumulated 10%. At the Li Shan station suspended load cumulated 55% when stream discharge cumulated 10%. The results are helpful to the sustainable development and management of the Hua Lien area.