圖書典藏及影音數位平台

花蓮溪為東部中央管河川之一，發源於中央山脈丹大山支脈之拔子山，主流流經花蓮縣較富裕之鄉鎮市，於花蓮市南郊吉安鄉境注入太平洋。 該溪水系河川大斷面樁於民國67年完成，後續分別於民國82、93、94年及97年辦理重測；後續於100年所測成果至今已逾5年餘，為更新河川斷面測量資料及因應各項工程設計、警戒水位之探討，同時配合105花蓮溪遊系整體河道沖淤比對及相關水文水理分析等工作之需，爰於105年辦理。

The construction of embedding piles in cross-section at Hualien River system was completed in 1978 with regard to the cross-section measuring results report where completed over the years in 1993, 2004, 2005, 2008 and 2011. In order to meet the needs of river system planning and management, it is necessary to make a comparison of the river management and emergency dredging. The team used the latest surveying and mapping equipment, the scope of its plan includes the mainstream of Hualien River, the main and secondary tributaries of a total of 8 rivers, a total of 409 measured cross-section, river length of about 170 km river about 75 square kilometers. An urgent need to use UAV unmanned aerial photogrammetry vehicle, a total of 7, 541 hectares of test area, unmanned vehicle practical training and case applications, and provide any typhoon and rainstorms during the disaster before and after the orthophoto Cross-sectional map data, integration of relevant data for hydrographic analysis and calculation. The project is based on the average river bed elevation of the 102-year review of the Hualien River Water System Management Plan of the Water Resources Department. For the sections where the siltation capacity is significantly reduced, the sections 08 to 12, 35 to 37 and Section 45 to 50 and other sections, as the proposed work area dredging. Nearly five years after the relevant dredging work has been carried out in succession, flood scouring and upstream gravel material shortage and other factors, resulting in most of the tributary showed erosion trend, siltation of the river is relatively minor, The tributaries assessed as follows: 1. Mugua River: For a long time for the erosion trend, nearly five years continued to brush deep, it is not recommended for dredging. 2. Lao River: In addition to the confluence of siltation is more serious, the remaining siltation of the average riverbed height increased by only about 0.08 ~ 0.85 meters, it is proposed not for dredging. In this case, 3. Shoufeng River: the last five years only part of a slight siltation section, the rest of the river section for the scouring trend, it is not recommended for dredging. 4. North Cingshuei River: In addition to the confluence of the mouth for the erosion trend, the remaining siltation of the average riverbed height increased by only about 0.08 ~ 0.85 meters, it is proposed not for dredging. 5. Fenglin River: nearly five years under the brushes are more than the case, the whole river section of the average river bed down about 0.18 meters, it is not recommended for dredging. 6. Wanli River: nearly five years for the erosion trend to section 13 over the erosion of the more obvious, it is not recommended for dredging. 7. Maan River: the last five years Section 04 The following sections of siltation, the average riverbed height increased by only about 0.47 meters, and more than 04 sections for the erosion situation, in view of the downstream river dredging, fear of causing the upper reaches of erosion Intensified, it is not recommended for dredging. 8. Guangfu River: the last five years cross-section 06 (Daxing Bridge) the following mostly silt river, the average river bed height increased by about 0.33 meters, then more than 06 cross-section erosion situation, in view of the downstream river dredging, fear Resulting in increased erosion upstream, it is not recommended for dredging. 9. South Cingshuei River: In addition to the confluence of the mouth for a slight siltation, the remaining sections are washed trend, it is proposed not for dredging. 10. Mofo River: In addition to cross-section 01 ~ 05 deposition is more obvious, the average riverbed elevation increased by about 1.24 meters, but by the water analysis results show that the current flood capacity can still meet the 50-year return period of protection standards, It is recommended follow-up as the case of siltation for dredging work, the rest of the river are washed trend. According to the results of hydrological analysis, the main stream of Hualien River and most of the tributaries are mostly scouring trend, so scouring the river should deepen the base of the structure and the base of the anti-impact and stability, and depending on the river The scouring situation should be adjusted. Considering the characteristics of the Hualien River and the variation of the riverbed, it is suggested that the average riverbed elevation of the "Review of the Hualien River Water System Management Plan" for 102 years should be based on the riverbed change before and after the future flooding. By regular inspections or surveys, And check the flood control capacity of the water management, such as the impact of river security or a high degree of water shortage, have to handle dredging work to maintain the capacity of river flood. The team in 104 for the Hualien River constructural survey, the Mofo River in the upper reaches of the new building embankment has not yet completed, so the plan to update the 1/1000 of topographic map data to facilitate your Bureau of construction planning and design. In addition, the team will build the whole basin of the 3D GIS system construction, which the image data compared to the three-dimensional screen display, cross-section data query, the key facilities, navigation, Measurement, rainfall, water station attributes and photo information query and other functions.