Hydrology and Climate Change

A glacier can be defined as a huge block of ice which is formed from falling snow. Glaciers contain almost all of the fresh water present on earth. Glaciers are formed in places where the temperatures are extremely cold. This could even include places that are at sea level, but are mostly places that are high up on mountains. In such cold places that it snows most of the year. This snowfall will settle down and when it snows again the lower layer of snow gets compressed. When the snowfall continue, the below layers will compress more finally turning into hard ice, it is accumulated getting bigger in size. This hard ice larger in size is the formation of the glacier. When the temperature increases slightly, the outer edges of the formed glacier and fresh snow will melt. If the melting of glacier is greater amount than the glacier formation, it is known as ablation of glacier. For a glacier to form and sustain itself it is of prime importance that the amount of snow that falls on it must be more than the amount of glacier that has melted. This is the only way in which the glacier will be able to maintain itself and keep increasing in size year after year. The increasing amount of glacier is known as accumulation of glacier.

The only criterion is that falling snow must exceed the melting ice to sustain the glacier. Many people worldwide depend on melting glaciers for survival. All their freshwater needs are met by these melting glaciers year through. This is the main sources of water and people use for drinking and irrigation purpose. But in these days glaciers are melting faster year by year than collection. It has not only creating avalanche and flooding in down stream but the fresh water resources are also vanishing.

It has been noticed that glaciers have melted more than normal over the past decades. Many glaciers in south-Asian continent have melted so fast over the past few decades that they have nearly to be vanished from the south face Himalayas. And the melting process is increasing each year such that many glaciers are reducing in size year after year because the falling snow is not able to replace the amount of melting ice.

Glaciers are melting faster today as compared to the past decades and the reason is sudden and rapid industrialization which in turn has caused global warming what we say green house effect. Global warming is nothing but the rise in average global temperature. The 'industrial revolution' is the main cause of this rise in average temperature. It is due to this increase in temperature that glaciers are melting more than they are accumulated. When a glacier melts fully, it exposes the earth surface below. Glaciers absorb approximately 20% heat from the sun, reflecting back 80%. When the earth gets exposed this percentage gets reversed. This in turn causes a further increase in temperature. This is a vicious trap which has already begun and it will be almost impossible for us to stop it totally. As a result, in the future, the global temperature will in all likelihood keep increasing, and melting glaciers even faster than they are today.