GEO-6 Regional Assessment for Asia and the Pacific


2.4 Freshwater


2.4.1 Introduction Water is a critical resource for human needs, agriculture, industrial production and preserving ecosystems. The Asia and the Pacific region has less than 30 per cent of the world’s internal renewable freshwater resources and there is extreme variation in per person availability from 1 179 cubic metres in South Asia to 31 669 cubic metres in the Pacific Islands (FAO 2014a). The region’s water resources thus need to be monitored, conserved and utilized judiciously to meet the increasing and competing demands.


2.4.2 Drivers


Water resources in Asia and the Pacific are stressed due to the large population, agricultural expansion and intensification, rapid urbanization, industrial growth and climate change.


With 60 per cent of global population, demand for food and energy are high. Of the total land area, 53 per cent was used for agriculture in 2007, rising by 6 per cent in 1970– 2007 in contrast to just a 1 per cent increase in the rest of the world (UNEP 2011). Agriculture’s water requirement is correspondingly high, accounting for 90 per cent and above


of withdrawals in several countries in South and Southeast Asia (FAO 2014b).


The primary energy demand in Asia and the Pacific was 4.985 billion tonnes of oil equivalent in 2010 and this is expected to increase by 2.1 per cent per year for the next 25 years, higher than the estimated world average growth rate of 1.5 per cent per year (ADB 2013a). Nuclear and coal-based thermal power plants consume 75–450 cubic metres of water per megawatt-hour (IEA 2012). Biofuel ethanol production is similarly water intensive, consuming 88.38 cubic metres per megawatt-hour for sugarcane cultivation and 0.522 cubic metres per megawatt-hour for ethanol processing (Spang et al. 2014).


Urbanization in Asia was 43 per cent in 2010 and is expected to reach 63 per cent in 2050, close to the global average of 67 per cent (ADB 2012). Of the 22 global mega-cities, with populations greater than 10 million, in 2013, 13 were in Asia (UNESCAP 2013) and 15 in 2014 (UN-Habitat and UNESCAP 2015). This large population concentrating in urban areas requires access to safe water and sanitation.


There are competing demands for water varying with the extent of urbanization. In South, Northeast and Southeast Asia, agriculture accounts for 82 per cent of water


Key Messages Water scarcity and deteriorating water quality challenge services and security in multiple dimensions including


human health, drinking water, sanitation, food production and loss of ecosystem services.


• Unsafe sanitation, disposal of untreated wastewater, runoff of agrochemicals contaminate surface and groundwater sources which are responsible for increased water-borne diseases, especially, in population-dense urban areas.


• Climate change effects on water security will be pronounced in rivers dependent on Himalayas. It will also cause alteration of rainfall patterns and sanitation of coastal aquifers, especially, in Small Island Nations and deltas;


• Widespread use of pharmaceutical and personal care products, nanomaterials, and organochlorides are contaminating various water sources leading to increased exposure to human health risk.


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