根據Schuster & Costa (1986) 研究顯示，不論是地震或豪雨崩塌形成的堰塞湖，50%會於形成後10日內潰決，但多數堰塞湖形成於集水區上游人煙稀少區域，現地調查與資料取得不易，亟需快速完成調查評估與防災作業。為在堰塞湖形成初期即能快速取得現場壩體幾何資訊，以評估壩體穩定性及後續潰壩情境等風險，本研究使用BigGIS平台提供之衛星影像以及數值地形線上分析工具，提出快速估算堰塞湖之迴水面積及蓄水量的方法，並以HEC-RAS二維洪水演算模組模擬不同情境下堰塞湖潰決時對下游保全對象造成的衝擊與影響。以2021年2月發生於台東卑南鄉東興村大南溪堰塞湖為例，不論是堰塞湖規模評估及其潰決後對下游的安全影響，本研究建立之堰塞湖快速評估作業方式，其結果均與現行調查結果相近，並可供後續防災決策參考。

According to Schuster & Costa (1986) statistical results, 50% of landslide dam would breach within 10 days, no matter earthquakes or torrential rains trigger the landslide to form the landslide dam. However, of the numerous kinds of dams form in upstream, basin or the desolated position where inaccessible to investigating. In order to evaluate and simulate the in-situ failure risk assessment, the aim of the current study was to 1. Operating the satellite images and function tools in BigGIS to assess the length and volume of backwater 2. Running different modules of two-dimensional flood routing model of HEC-RAS to evaluate the impact of downstream communities. In conclusions, the results of standard operating procedure method of evaluation and operation dam failure models were similarly with the in-situ investigation, whether occurred lake ranges or assessed the effect of the Da-Nan River downstream in Taitung, Taiwan.