氣候變遷導致複合型災害，堪塞湖與其所造成之災害已有逐漸增多之趨勢。堪塞湖的形成多是因為崩塌、地滑、土石流堵塞河道所致，因此天然壩的安全性遠不及以工程方法構築之人工壩，這也就是天然壩易產生潰決，以至於釀成巨災的原因。大多數的堰塞湖年限極短，主要潰決原因為溢流溯源沖刷。堰塞湖的壽命及潰決方式，受制於天然壩體大小、堵河之土砂材料特性、上游來水條件以及堰塞湖之蓄水容量等。2009年8月7到9日颱風莫拉克侵襲臺灣地區， 超大的降雨造成東部與中南部的嚴重水患洪災，其受害規模與程度不亞於921地震災害，使得山坡地的崩塌、地滑或土石流數量暴增，堆積土石堵塞河道形成了大大小小的堰塞湖，初步研判的新生堰塞湖有17處。這些暴雨所形成之堰塞湖的壩身多矮而長，且在短時間內都發生過不同程度的潰決，而潰決的同時也造成河道的嚴重沖淤與水位變化，並且對下游村落造成一定程度之傷害，其中以小林村為甚。現存之堰塞湖則因均已溢流，雖然危險度已大幅降低，但建立完善的危機管理對策仍刻不容援。

Compound disasters are caused by climate change， so the landslide dams and its secondary disasters have already increasing gradually. The landslide dam forming mostly from rock fall， landslide and debris flow stopping up river， so the safety of the natural dam is not far as with the artificial dam where the engineering method constructs. This is that the natural dam is apt to produce bursting and lead to the failure reason. Most life of landslide dams are extremely short， the reasons are overflow and headcutting mainly. The life-span and way of failure of the landslide dam are situated in size of dam， soil material， inflow and capacity of the barrier lake etc. Typhoon Morakot attacked Taiwan in 7-9 Aug. 2009， the heavy rainfall caused the serious flood in the east and central-south Taiwan， its injured scale and degree were not second to Chichiearthquake disasters. The heavy rainfall caused the quantity of slopeland fault， landslide and debris flow increasing， have piled up the soil material and blocked up the river and formed 17 landslide dams. These landslide dams overwhelming majority failure of various degree within short time， cause flushing， and morphological change seriously in the river while failure， and cause the injury of a certain degree to the downstream communities， especially Siaolin village. Hence the extant landslide dams have already overflowed， thus the dangerous degree has already been reduced by a wide margin. However， the engineering mitigation and risk management of landslide dam demand immediate attention in the future.