UAV輔助農田灌溉進水口易淤積區域調查與潛在災害分析

旗山圳一幹線進水口，為旗山地區重要農田灌溉水源源頭，該進水口於八八風災期間受旗山溪土砂掩埋導致無法取水。為降低颱風等天然災害對於農民賴以為生之農地危害及農田水利設施之損壞，本研究利用無人飛行載具協助調查旗山圳一幹線進水口地區易淤積區域調查與潛在災害分析，期能因應超大豪雨或颱風過後等天然因素對進水口之影響。分析調查結果顯示旗山圳一幹線進水口位於旗山溪下游地區，上游於颱風豪雨期間常有堰塞湖形成，河岸崩塌及支流發生土石流等事件發生，造成位於下游的進水口地區遭土砂掩埋、漂流木堵塞及溪水泥沙含量增高，導致進水困難。除建議修復目前溪床固床工端部損毀部分與支流損毀整流工程避免持續沖刷外，考量後續營運維護成本與進水穩定性，建議搭配地下伏流水之取用設計，增設集水廊道取伏流水連接現有引水渠道，以補旱季灌溉水源不足問題。避免土砂災害發生造成斷水後，才進行事後補救措施，讓水資源能更有效運用，提升管理效率。

關鍵字

旗山圳；農田灌溉；易淤積區域；潛在災害分析；無人載具

並列摘要

The irrigation water inlet of the Qishan first-canal waterway is a central agricultural water resource facility in the Qishan district of Kaohsiung City in southern Taiwan. The inlet was buried by masses of debris during Typhoon Morakot, which landed in Taiwan in 2009. In an attempt to reduce the effects of natural hazards on agricultural lands and hydraulic engineering, an unmanned aerial system (UAS) was used to investigate the stream water inlet of the Qishan first-canal waterway for potential sediments and analyze areas vulnerable to hazards. The results of the analysis revealed that the inlet was located downstream of the Qishan River and that numerous sediments from debris flows, riverbank landslides, and natural dams flowed downstream. The inlet can be buried in sediment and clogged by floodwood, and the hyperconcentration of sediments cause the water to be untakable. A designated water collection gallery for taking the subsurface water connecting to the waterway should be created to maintain the water volume during dry seasons.