GLOFs, can be defined as the sudden release of water from a lake that is in contact with a glacier. Climate change has led to rapid changes in glaciers which in turn has led to the expansion of glacial lakes or the formation of new ones. Many GLOFs have occurred where there is no historical evidence of such floods occurring previously. GLOFs can be huge, and the flood water can carry significant amounts of sediment and other debris. However, how dangerous a GLOF can be depends on whether there are settlements or infrastructure downstream in the flood zone. In the Hindu Kush Himalaya, major damage can occur in areas far from the glacier itself, and people affected may not have been aware of the existence of the lake before it burst. Lowering the lake level can either make the lake much less likely to flood or make the volume of such a flood much lower and hence much less damaging. However, doing this kind of mitigation in remote areas and at high elevation in the is often prohibitively difficult. In such cases, early warning systems can give communities the chance to get away from the flood zone before the flood water arrives. The distance from the glacial lake is often far enough that sufficient warning time can be given as soon as a lowering in lake level or increase in discharge is noted. It is imperative that such warning systems are established in close agreement with the local community. Although such warning systems cannot save infrastructure, they can help greatly in saving lives and reducing injury.
