圖書典藏及影音數位平台

鹽港溪大斷面測量

Channel measurement for the governance and management of the necessary work, including large cross section measurement is necessary to handle projects on a regular basis, to facilitate the management units understand channel water capacity, changes in the elevation of existing dikes and channels, and so on, for " The achievement report of a cross-section survey for the Yan-Gang-Si Drainage " program, in this case work completed during the implementation of the scheme are as follows: 1.the measuring section : measurement job aspects amounted to (1) detection known plane points 5 points, and (2) detection known elevation points 5 points, and (3) measurement section pile 284 points and the aerial standard 15 points, and (4) completed 142 at section measurement and the structure real survey job (revetment type State, and across Canal structure real, and flood control structure real and the into workers, survey), and (5) completed color aviation photography measurement (numerical are shot image figure, and 1/1,000 numerical topographic maps, and DEM results), and (6) completed drainage map identificatications finishing meter 38 site, and (7) Complete salt Canal Creek drainage in Yan-Gang-Si current status land use mapping, and (8) the collection of 8 photos map and channel number, and (9)Photomesh 3D model construction, and (10) interactive 3D GIS build operations. 2.analysis of river morphology image interpretation : Orthophoto of the planning region in line with the value of production, and on aerial photo interpretation techniques to handle image interpretation, and analyze water, River Plate texture, drainage patterns, stream habitat and cross drainage structures, clear of ecosystems and environmental factors, as a future reference to create diverse habitats. 3.analysis of bed material sampling: 10 bed load survey meter, accordingto the results of sample analysis estimates the manning roughness coefficient n values in the range of 0.013~0.018. 4.water analysis: Water capacity hydraulic routing mode used HEC-RAS model for review, manning roughness coefficient n-value mining 0.025~0.035. Other exports because it is in the sea, tide starting water level recovery in July-October the mean high tide level EL.2.3 meter run. 5.the existing structure safety review : (1)Bank top security review and flood control structures: At present Salt Creek drainage of the existing flood control structures include include left and right bank 9,385 meters. By water acting calculus results known, South XING Qiao for territories, South XING Qiao to downstream at only has sporadic of water high insufficient, to upstream at by section 32 to country 1 highway bridge section 44 Qian, more to upstream more has water high and the di high insufficient of trend, which section 41 to section 43 are has di high insufficient of case, remaining are can meet their river protection standard. (2)safety review cross-channel structure: Investigation of the case and cross-channel structure of a total of 19 bridges, the Insufficient span is Chung-Hsing bridge, Ming-Der bridges and Hsing-Fung bridge, Nan-hsing bridges, I- Fung bridges and Hsing-Fung bridge height less than at the end of it. 6.analysis on channel scouring and silting variation change: (1)the profile comparison: Than on 94 and 104 section survey results Riverbed changes, section 00~ section 02, section 02-2~ section 06, section 16-1~ section 16-2 and section 46-2~ section 46-3 deposition phenomena, most of the remaining sections are flush. Among them, Nan-hsing bridges upstream sections were scour phenomenon ispartly due to engineering applied, not natural erosion. (2)sand changes : lose sand mining NETSTARS analysis in the present case, NETSTARS losing sand for quasi two dimensional models with different return periods from the peak flow, simulation analysis of the Salt Creek drainage of sand lost in Yan-Gang-Si Drainage. (3)bridge local scour depth : bridge local scour, contraction scour the beam depth and general scour the sum total scour depth is the depth of each of the three bridges, the achievements show the total amount of each bridge scour depth between 3.89m (railway bridge) ~ 5.65m (highway bridge) . (4)Channel Change Analysis : 91 years, 99 years, 101 years and 103 years of the number of flow paths to be drawn into a transition diagram, the results show significantly exceeded 91 years in many revetment and 99 years in Shing-Chen bridge upstream revetment slightly beyond, the rest of the year the flow path.

這份報告是關於鹽港溪排水的大斷面測量計畫。鹽港溪是新竹與苗栗交界的重要河川，全長約12公里。本次計畫旨在透過定期的大斷面測量，讓管理單位了解其通洪能力、堤防高程及渠道變動情況。 計畫內容包含：已知控制點檢測、斷面樁埋設與測量、大斷面測量、防洪及跨渠構造物調查、彩色航空攝影、河床質調查分析、土地利用現況圖製作、數值化渠道範圍、河川型態影像判釋、排水圖籍整理、構造物安全分析、渠道沖淤變化分析及3D GIS成果建置等。 報告中詳細記錄了測量作業、河川型態影像判釋、河床質採樣分析、水理分析、現有構造物安全檢討以及渠道沖淤變化分析的成果。其中，堤防高程在南興橋下游處有零星不足，往上游處有愈趨嚴重的趨勢；部分橋梁的跨距或梁底高程亦有不足。沖淤變化方面，部分斷面呈現淤積，大部分呈現沖刷。