A Unique Resource 1.2. World Water Distribution
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1. INTRODUCTION 1.1. Water – A Unique Resource We live on the water planet with precious film of water. Of all the planet‟s renewable resources, water has a unique place. Water also plays a key role in (i) sculpting the earth‟s surface (ii) moderating climate and (iii) diluting pollution. All organisms (50-97% of the weight of all plants & animals and about 70% of human body) are made up mostly of water and it is the lifeblood of the biosphere (Buchholz, 1998). It connects us to one another, to other forms of life and to the entire planet. Each of us needs only about a dozen cupfuls of water per day to survive, but huge amounts of water are needed to supply us with food, shelter and our other needs and wants. Despite its importance, water is one of our most poorly managed resources. We waste it and pollute it (Fakayode, 2005). We also charge too little for making it available. This encourages still greater waste and pollution of this resource, for which there is no substitute. (Miller, 2004) 1.2. World Water Distribution Out of the world water resources 97.3% are in the oceans as salt water; 0.001% in the atmosphere as water vapor and 2.8% on the land area in various forms. Out of this 2.8%, water in the ice caps and glaciers contribute to 2.14% and the share of rivers is only 0.0001% (Peavy et al., 1985). Two continents share almost 150 of the world‟s 214 major river systems (57 of them in Africa), and another 50 are shared by 3 to 10 countries. Some 40% of the world‟s population already clashed over water, especially in the Middle East. Some areas have lots of water, but the largest Rivers (which carry most of the runoff) are far from agricultural and population centers where the water is needed. For example, South America has the largest annual water runoff of any continent, but 60% of the runoff flows through the Amazon River in remote areas where few people live. In some areas, overall precipitation may be plentiful, but most arrives during short periods, or it cannot be collected and stored because of a lack of water storage capacity. For example, only few hours of rain provide more than half of India‟s rainfall during a four-month monsoon season. 1 1.3. Surface Water Water collecting on the ground or in a stream, river, lake, wetland, or ocean is called surface water, as opposed to groundwater or atmospheric water. Land surface water is the largest source of fresh water, supplied by rain. The quantity of this utilizable water is very much limited on earth (Mathur and Maheswari, 2005). Only about 0.014% of the earth‟s total volume of water is easily available to us as soil moisture, usable ground water, water vapor, lakes and streams. If the world‟s water supply were only 100 liters, our usable supply of fresh water would be only about 0.014 litres. This amounts to a generous supply as long as we do not (i) overload it with slowly degradable and non-degradable wastes or (ii) withdraw it from underground supplies faster than it is replenished. Unfortunately in some parts of the world we are doing both (Gray, 2005). 1.4. Causes of Freshwater Scarcity Water shortage may be due to the scarcity of quantity, loss of quality or economic inability. 1.4.1. Scarcity of quantity According to water expert Falkenmark (1990), there are four causes of water scarcity: (i) global warming (ii) drought (a period of 21 days or longer in which precipitation is at least 70% lower and evaporation is higher than normal), (iii) desiccation (drying of the soil because of such activities as deforestation and overgrazing by livestock), and (iv) water stress (low per capita availability of water caused by increasing numbers of people relying on limited runoff levels). Global warming can (i) increase global rates of evaporation (ii) shift precipitation patterns and (iii) disrupt water supplies and thus food supplies. Some areas will get more precipitation and some less. River flows will change. Monsoons and hurricanes are likely to intensify. The average sea level will rise from thermal expansion of oceans and partial melting of ice caps and mountain glaciers (Miller, 2004). Since the 1970s, intensified by prolonged drought water scarcity, has killed more than 24,000 people per year and created millions of environmental refugees. In water-short rural areas in developing countries, many women and children must walk long distances each day, carrying heavy jars or cans, to get a meager and sometimes contaminated supply of water. 2 A country is said to be water stressed when the volume of reliable runoff per person drops below about 1,700 cubic meters (60,000 cubic feet) per year. According to a 2,000 study by the World Resources Institute (WRI), 2.3 billion people live in river basins under moderate to high water stress. Of this group, 1.7 million live in areas of water scarcity, where annual per capita water availability falls below 1,000 cubic meters (35,000 cubic feet). If current water consumption patterns continue, the WRI projects that by 2025 at least 3.4 billion people will live in water stressed river basins in 50 countries, with more than 2.4 billion of these people suffering from more dire water scarcity. 1.4.2. Loss of Quality (River water pollution) The quality of water has generally been signified by its origin, terrain through which it flows and most importantly the extent to which it is contaminated on its way by anthropogenic means (Bordoloi et al., 2002). Many human activities can pollute rivers. Industry, housing, agriculture, horticulture, transport and discharges from the many disused mines can all affect water quality. The other anthropogenic activities are disposal of dead bodies, cattle wading, bathing, open defecation, cloth washing, disposal of waste, etc. (Saksena et al., 2008 and Verma and Saksena, 2010). Pollution may arise as point sources, such as discharges through pipes which may be easily identifiable, or may be more dispersed over a wider area, known as diffuse pollution. Available data indicate that river pollution from discharges of sewage and industrial waste is a serious and growing problem. In most developing countries, where waste treatment is practically nonexistent. Numerous rivers in Russia and eastern European countries are severely polluted. Of the 78 streams monitored in China 54 are seriously polluted with sewage and industrial waste. Same is the story in Latin America and Africa. India has about 3200 major industries and a large number of small scale industries discharging their effluents into the rivers (Murugesan, 1988). Despite progress in improving stream quality in most developed countries, large fish kills and drinking water contamination still occur. Most of these disasters are caused by (i) accidental or deliberate release of toxic chemicals by industries or mines (ii) mall functioning sewage treatment plants and (iii) nonpoint runoff of 3 pesticides and nutrients (eroded soil, fertilizer and animal waste) from crop land or animal feedlots (Miller, 2004). The natural hydrological processes are overtaken by man‟s influence of water courses lead to changes in canal morphologies, increased catchment, imperviousness and contamination of water quality (Kinyari, 2012). Contaminants such as bacteria, viruses, heavy metals, nitrates and salts have various ill effects on human health (Akoto and Adiyiah, 2007). Minamata disease incidents of 1908 and “itai-itai” disease (1912-25) in Japan are the most famous examples of damage to public health (Fuji and Hu, 2002). Typhoid and cholera have the epidemics during the dry seasons (Edwards, 1993). Even in developed nations like the USA cases of outbreaks of diseases associated with contaminated potable water was reported (Moore et al., 1993). 1.4.3. Economic Inability Even when there is a plentiful supply of water, most of the 1.2 billion poor people living on less than $1 a day cannot afford a safe supply of drinking water. Most are cut off from municipal water supplies and must (i) collect water from unsafe sources or (ii) buy water (often coming from polluted Rivers) from private vendors at high prices. In developing countries, people not connected to municipal water supplies on an average pay 12 times more per liter of water than people connected to such systems and in some areas pay up to 100 times as much. A number of environmental, political, and economic analysts believe that access to water resources, already a key foreign policy and environmental security issue for water short countries, will become even more important over the next 10- 20 years. As population, irrigation and industrialization increase, water shortages in already water short regions will intensity and heighten tension between and within countries. 1.5. Achieving more sustainable use of the earth’s river water resources are as follows:- Not depleting the aquifers Conserving the ecological health of the aquatic systems Preserving the water quality Integrating watershed management 4 Sharing surface water resources through agreements among regions and countries Settling disputes of water between nations through outside party mediation Marketing of water rights Wasting less water Decreasing government subsides for supplying water Increasing government subsides for reducing water waste Slowing population growth 1.6. Need for Monitoring of River Water Quality We depend on surface and groundwater sources for drinking water, to generate energy, to grow our crops, to harvest fish, to run machinery, to carry wastes and to enhance the Isle of Man‟s scenic landscape. We use water for washing and cleaning, industrial abstraction, recreation, cooking, gardening and angling.