234
during which much water evaporates, runs off, or drains below the root zone. Other
irrigation methods which are more efficient and more expensive include drip or
trickle irrigation, surge irrigation, and some types of sprinkler systems where the
sprinklers are operated near ground level. Issues often insufficiently considered
when applying irrigation methods are salinization of groundwater and contaminant
accumulation leading to water quality declines, which is the reason of the sharp rising of water scarcity.
Consequently, the misuse of natural resource is leading to its runout in the near
future due to the rapid increase in world population. In 2000, the world population
was 6.2 billion. This number will increase to 9.7 billion by 2050 according to the
estimation of the UN which growth mainly comes from developing countries suffering water stress [18]. Therefore, the water demand will also increase unless water
conservation or recycling increases [18]. The World Bank explained the result of the
UN’s research that access to water will be one of the main challenges in the near
future [3]. Simultaneously, urbanization is also increasing rapidly. In low-density
communities, small private wells and septic tanks are commonly used to provide
water, which is not so useful in high-density urban areas. To deliver water to individuals and concentrate wastewater, urbanization requires large investment from
individuals and businesses in water infrastructure. In 60% of European cities with
more than 100,000 people, the replenishing rate of groundwater is less than consuming rate. Even if some water can be utilized, a large amount of cost will be
needed to capture it. Recent research revealed that in 2025, water shortage problems
will be more obvious among poorer areas with limited resources and rapid population growth, such as the Middle East, parts of Asia, and Africa. Besides, at that time,
to provide clean water and adequate sanitation, large urban and peri-urban areas will
need to construct new infrastructure, which may lead to growing conflicts between
government and agricultural water users, who currently consume most of the water.
Compared to these poorer areas, more developed areas of North America, Europe,
and Russia will not suffer the threat, not only because of their relative wealth, but
also because their population can better align with available water resources.
Subsequently, one of the major concerns today is water pollution and many countries have tried hard to find solutions to solve this problem. Among all pollutants
threatening water supplies, the most widespread one is the discharge of raw sewage,
sludge, garbage, or even toxic pollutants into natural water, which is most common
in underdeveloped countries and some quasi- developed countries like India, Iran,
China, and Nepal. Treated sewage can form sludge, which may be placed in landfills, spread out on land, incinerated, or dumped at sea. Except for sewage, nonpoint
source pollution such as agricultural runoff, urban storm water runoff, and chemical
wastes is also a major source of pollution in some countries. Simply, the misuse of
water resources worldwide significantly impacts the climate change because of the
close connections between the climate and hydrological cycle. Increased hydrologic
variability and change in climate have and will continue to have a profound impact
on the water sector through the hydrologic cycle, water availability, water demand,
and water allocation at the global, regional, basin, and local levels.
12 Potable Water
during which much water evaporates, runs off, or drains below the root zone. Other
irrigation methods which are more efficient and more expensive include drip or
trickle irrigation, surge irrigation, and some types of sprinkler systems where the
sprinklers are operated near ground level. Issues often insufficiently considered
when applying irrigation methods are salinization of groundwater and contaminant
accumulation leading to water quality declines, which is the reason of the sharp rising of water scarcity.
Consequently, the misuse of natural resource is leading to its runout in the near
future due to the rapid increase in world population. In 2000, the world population
was 6.2 billion. This number will increase to 9.7 billion by 2050 according to the
estimation of the UN which growth mainly comes from developing countries suffering water stress [18]. Therefore, the water demand will also increase unless water
conservation or recycling increases [18]. The World Bank explained the result of the
UN’s research that access to water will be one of the main challenges in the near
future [3]. Simultaneously, urbanization is also increasing rapidly. In low-density
communities, small private wells and septic tanks are commonly used to provide
water, which is not so useful in high-density urban areas. To deliver water to individuals and concentrate wastewater, urbanization requires large investment from
individuals and businesses in water infrastructure. In 60% of European cities with
more than 100,000 people, the replenishing rate of groundwater is less than consuming rate. Even if some water can be utilized, a large amount of cost will be
needed to capture it. Recent research revealed that in 2025, water shortage problems
will be more obvious among poorer areas with limited resources and rapid population growth, such as the Middle East, parts of Asia, and Africa. Besides, at that time,
to provide clean water and adequate sanitation, large urban and peri-urban areas will
need to construct new infrastructure, which may lead to growing conflicts between
government and agricultural water users, who currently consume most of the water.
Compared to these poorer areas, more developed areas of North America, Europe,
and Russia will not suffer the threat, not only because of their relative wealth, but
also because their population can better align with available water resources.
Subsequently, one of the major concerns today is water pollution and many countries have tried hard to find solutions to solve this problem. Among all pollutants
threatening water supplies, the most widespread one is the discharge of raw sewage,
sludge, garbage, or even toxic pollutants into natural water, which is most common
in underdeveloped countries and some quasi- developed countries like India, Iran,
China, and Nepal. Treated sewage can form sludge, which may be placed in landfills, spread out on land, incinerated, or dumped at sea. Except for sewage, nonpoint
source pollution such as agricultural runoff, urban storm water runoff, and chemical
wastes is also a major source of pollution in some countries. Simply, the misuse of
water resources worldwide significantly impacts the climate change because of the
close connections between the climate and hydrological cycle. Increased hydrologic
variability and change in climate have and will continue to have a profound impact
on the water sector through the hydrologic cycle, water availability, water demand,
and water allocation at the global, regional, basin, and local levels.
12 Potable Water