- 期刊
大甲溪輸砂量估算之數學模式研究
A study on the Mathematical Model for Sediment Load Estimation of the Ta-Chia Stream Watershed
摘要
本省之河川，多屬源短流急、坡度陡峻者，加之受人爲因素之破壞，其輸砂量較歐、美、日等各國超出甚多，因此，外來輸砂公式若不加修正，難以適用於本地之河川。然由於多數之河川，其流域曲折險峻，輸砂量（尤其推移量）之測定極爲困難，而欲誘導眞正適合於本地某一河系之輸砂量，實屬不易。據此，目前本省各河川輸砂量之估算，均利用外來公式而憑經驗及局部之觀測值加以粗略之修正，其估測值之可信度必然甚低。爲解決此一問題，筆者在前期（本學報第五卷、第二期）中曾以「臺灣中部地區河川流力冲蝕與輸砂估算數學模式之初步研究」爲題，敍述本人粗淺之構想。此後，在農復會及國科會之專案補助，以及水利局河川治理規劃總隊之協助下，選擇大甲溪上游段，七家灣溪及雪山溪上所設置之攔砂壩間，作貝蒂颱風洪水前後之實地勘測與採樣分析，以其結果作爲本文探討之依據，料對於大甲溪上游流域輸砂公式之選擇與應用上，將獲致合理之改善。今後，續將利用模型試驗進行各種不同流量、坡度及顆粒級配下之理論探討，以作爲更精確之修正，並進而估算衆所矚目之德基水庫壽命。此一結果擬於本學報下一期中發表。
關鍵字
無資料並列摘要
On account of the geographical, geological and hydrological reasons, the amount of sand-sediment of the streams in Taiwan is quite large, and highly exceeds, in amount, almost all the streams in foreign countries, such as U. S. A., Japan and Germany. For this reason, the foreign empirical formulas for the estimation of sedimentation can not be applied without further modification and correction. It is difficult to measure the sediment load, because of danger and complexity. For the time being, the estimation of the sediment load in Taiwan rivers has been corrected roughly by experiences and some observations in details, therefore, the reliability must be low. To solve this problem, the author had offered some ideas which published on the same Journal in vol. 5. No. 2: ＂A preliminary study on Hydrodynamic Erosion and Mathematical Model of Sand-Sediment Estimation for the Streams in Central Taiwan＂, and this can be seen as the preliminary of this paper. This study has been started under the financial support of J. C. C. R and N. S. C, and the help of Water Bureau in this summer. In order to adjust the foreign empirical formulas for Ta-chia stream watershed, we choose the interval of the river reaches with the dams which constructed on Chi-Chia-Wan chi and Shua-San chi as a check. The author also carried the survey and investigation of the cross-sections of river beds, and analyzed the bed materials by sampling. In the next step, the author will continue to practice the model test by different discharge, slope, and sand diameter for the sake of working theoretical discussion and modification of the various foreign empirical formulas more exectly. In the future time, we hope that the application of the result in this study, it is able to estimate the life of To-chi Reservoir more correctly.