Over Exploitation of Groundwater in Third World Countries Particularly in South Asia to Meet the Hunger of Billions of Population – A Threat to Drinking Water In 21st Century

Water shortages and water pollution constrain development in general and food production in particular (UN, 1997). Of all the water on the planet, only 3% is fresh water, and most of this is frozen in icecaps and glaciers or is in underground aquifers. Only about one-hundredth of 1% of the world’s total water supply is readily available for human use. This amount would be sufficient for current needs, if evenly distributed (Lean et al. 1994). Of course water is not evenly distributed. For example, in arid Saudi Arabia about 40 people must have the same amount of water that is available to one person in tropical Malaysia (UN, 1996).

Hydrologist Malin Faikenmark and colleagues have calculated that once a country’s available water resources drop below 1700 cubic meters per person per year, the country can be expected to experience regular water stress. If the amount of water available per capita drops below 500 cusic meters per person per year, countries face conditions of absolute water scarcity (Englman et al, 1993; Faikenmark et al, 1992; UN, 1997). In the third world countries, the population is increasing according to the Malthus principle (Agricultural production increases in arithmetic progression while food production in geometric progression). This causes loss of agricultural land to urbanization. There will be more population; there will be more need of water. Water scarcity or chronic stress makes it difficult to expand agricultural production to keep pace with population growth. In 1990, 28 countries with a combined population of 335 million faced chronic water stress or outright scarcity. By 2025, 52 countries may face water shortage, affecting over three billion people – about 40% of the world’s projected population (Englman et al, 1993; Un, 1997). The 20 countries of the Near East and North Africa face the worst prospects, annual per capita water availability already has fallen to only 1250 cusic meters, 60% less than in 1960.  

By 2025, per capita supplies are projected to fall another 50%, to 650 cubic meter. Currently Jordan and Yemen withdraw 30% more water from groundwater aquifers every year than is replenished (Englman et al, 1993; Postel, 1996; WB, 1995).

Urbanization in the third world countries particularly in South Asia is not only responsible for loss of agricultural land and depletion of water resources but also is causing pollution due to utilization of too much and too many fertilizers. In many countries water pollution has contributed to water shortages and thus constrained food production, as well as caused health problems. For example, of 78 major rivers in China, 54 are seriously polluted. More than 40% of Malaysia’s rivers are so fouled with municipal, industrial and agricultural wastes that they are biologically dead (Hinrichsen, 1996). The nearly 450 cubic kilometers of waste water that is discharged into surface water every year require an additional 6000 cubic kilometers of freshwater, two third of world’s total stable water runoff, to dilute the waste water and carry it to the oceans (WHO, 1997). Same is the case with many rivers in India, Pakistan, Bangladesh and other South Asian countries.

The world needs a “blue revolution” as much as it needs another Green Revolution. Based on the UN medium population projection, over 4 billion people would be affected by water shortage in the year 2050. By then, for example, in Nigeria only about 900 cubic meters would be available per person, compared with 3200 cubic meters per person in 1990 (Englman et al, 1993).

A water shortage world is an unstable one. More than 200 river systems cross international borders; nearly 100 countries have just 13 major rivers and lakes (Englman et al, 1993; Postel, 1996). Water use practices in upstream countries can affect water supplies in downstream countries. Disputes can arise, especially where countries with rapid population growth and limited arable land and water supplies vie for access to water. For example Ethiopia plans to divert more of the Blue Nile’s water for irrigated agriculture, while Egypt, downstream, depends on the Nile’s waters for its very existence (Hinrichsen, 1996).

Instead of “first come, first served” approach to water management, countries and regions need to manage distribution and use of water resources to ensure that everyone gets a fair share. Guaranteeing access to water supplies also would be help food-deficit countries improve their agricultural production. Some countries has successfully negotiated agreements over use of water resources for example, India and Bangladesh, which share the Ganges, the largest and most important river on the India sub-continent (UN, 1995).

With the prospect of less water per person, countries must conserve available water resources and manage them better in the Past. Many strategies and technologies exist to help save water and distribute it equitably. These include building reservoirs and small catchment dams to collect water during the rainy season for use during the dry season, allowing aquifers to recharge, reducing leaks in urban water pipes, protecting water-sheds by plantation to reduce erosion, and recycling municipal waste for agricultural use.

Author(s):
Akhileshwar Tiwari and V.S. Dube
Department of Geology, Patna University, Patna, India.

Poonam Ojha
Department of Chemistry, Magadh University, Bodh-Gaya, India.