圖書典藏及影音數位平台

大斷面測量為河道河川警戒水位之制定、洪水淹水範圍之水理演算、輸砂、河防構造物之規劃設計及河川管理、跨河構造物及固床工之安全調查、河床沖淤分析等均需依此基本資料，爰此，每年辦理大斷面觀測工作，俾供河川治理及檢討警戒水位之參考。

The large-section measurement is the basic information for the determination of river warning water level , the water calculus of flood flooding area , the design of sand transport , river defense structure and river management , the safety investigation of river-crossing structures and solid-bed workers , the analysis of river bed erosion and siltation , etc. , in this regard, The 7th River Management Office continued to handle the " The observation and investigation of cross sections and important bridges in the Kaoping River Basin". This project took 7 months to complete all field surveying operations, and completed the project ○1 site survey; ○2 plane control survey; ○3 elevation control survey; ○4 section pile embedment and coordinate elevation survey; ○5 river course Section measurement; ○6 important bridge and fixed bed engineering large section measurement; ○7 four feedback projects. After collecting historical cross-section data of the main and tributary rivers, bridges, and fixed beds of the Kaoping River and the large-section results measured in conjunction with this project, analyze and compare the average river bed height of each bridge section and fixed bed section , The depth of erosion and deposition, etc., the main stream of the Kaoping River shows mutual erosion and deposition. Because the river is still wide, it will not seriously affect the function of flood discharge and sand transportation, and the river is still stable. The Laonong River below Xinfa Bridge is scouring. Because the river is still wide, it will not seriously affect the flood discharge and sand transport function of the river. Above the Xinfa Bridge, there is mutual erosion and silting, and the river is still stable. The cross-sections of Qishan River from Qiwei Bridge and Qishan Bridge have changed greatly, and most of them are scoured. The bridges from Yuemei Bridge and above are scouring and silting, and the bridge sections are still stable. The entire section of the Ailiao River is scouring and silting, and there is no obvious change in each section. Only the downstream of Xinsandimen Bridge, the erosion is -2.03m~3.10m, and the river course is still stable. The Wuluo River is scouring and silting, and only the cross-section 7-1 scours -3.01m, but the single cross-section has slight changes, and the other cross-sections have no obvious changes, and the river is still stable. The whole section of Wulu River is scour-like, and all sections are scour-like, scour -3.19m (section 1), scour -3.93m (section 2), scour -2.18m (section 3), scour -1.61m ( Section 4), the average scouring depth of the entire river section is as high as -2.73m, and attention should be paid to the safety of its river defense structures. The entire section of the Kouaixi River is scouring and silting, only section 33-1 has a siltation of 2.93m and section 41 has a siltation of 3.86m, and the channel is still stable. The whole section of Zhuokou River is mostly siltated, and only section 28 is scoured -4.18m, and the river course is still stable.