71% of our earth surface is covered with water. It is about 332.5 million cubic miles. 97% of that water is found in our oceans. This water is saturated with salt and undrinkable. Of the remaining 3% potentially usable freshwater more than two thirds is locked away in glaciers or deep underground and less than 1% of it is available to us. At present large number people is suffering from water scarcity. They don’t have access to safe, clean drinking water. More than half the world’s population endures extreme water scarcity for at least one month a year.
Water scarcity is a result of an imbalance between the supply of and demand for water sources in a geographical area. Water scarcity involves water stress, water shortage or deficits and water crisis. Limited or inadequate water supply is one of the toughest issues facing the world’s most country. Water scarcity can be a result of two mechanisms. Physical water scarcity and economic water scarcity, where physical water scarcity is a result of inadequate natural water resources to supply a region’s demand and economic water scarcity is a result of poor management of the sufficient available water resources. Water shortages may be caused by climate change such as altered weather pattern including droughts or floods, increased population and increased human demand and over use of water. Water scarcity is being driven by two converging phenomena, growing freshwater use and depletion of useable freshwater resources.
Some part of earth has already run out of ground water. Several parts of the world are facing acute water crisis. The UN says by 2050 more than 5 billion people could be facing water shortage across the world. Current estimates predict that by 2040 up to 20 more countries could be experiencing water shortage.
These bleak statistics raise a startling question – are we running out of clean water? Of course not. Earth can’t run out of fresh water because of water cycle, a system that continuously produces and recycle water. Water are being rapidly depleted by humans but slowly replenished by rain & snowfall. This limited supply is not distributed evenly around the globe. Diverse climate and geography provide some regions with more rainfall and natural water sources, while other areas have geographic features that make transporting water much more difficult.So, this is not really a question of how much water there is, but of how much of it is accessible to us.
Agriculture accounts for 70% of water which is withdrawn globally. Agriculture currently covers 37% of earth’s land area, posing the biggest threat to our regional water supplies. So we have to take initiatives to reduce water uses in agriculture. Scientist are already finding ingenious ways to reduce water use like using special irrigation techniques to grow “ more crop per drop” and breeding new crops that are less thirsty. On a personal level reducing food waste is the first step to reducing water waste. Recycling of waste water is also a better option to reduce water waste. Desalination of water could be a better alternative but it is costly and it requires more energy.
Today water scarcity is an alarming issue. Former World Bank vice president Dr. Ismail Serageldin said, “The wars of this century were fought over oil. The wars of the next century will be fought over water unless we change our approach to managing these precious and vital resources”. Cross border conflicts over water could rise 95% by 2119. So we need to be aware of this and take appropriate action.
Afsana Rezoana Sultana, MS in Agronomy, Patuakhali Science & Technology University