Fresh water as a resource Fresh water

1 fresh water resource

1.1 agriculture
1.2 limited resource
1.3 fresh water withdrawal
1.4 causes of limited fresh water
1.5 fresh water in future
1.6 choices in use of fresh water

fresh water resource

water fountain found in small swiss village. used drinking water source people , cattle. every alpine village has such water source.

an important concern hydrological ecosystems securing minimum streamflow, preserving , restoring instream water allocations. fresh water important natural resource necessary survival of ecosystems. use of water humans activities such irrigation , industrial applications can have adverse impacts on down-stream ecosystems. chemical contamination of fresh water can damage eco-systems.

pollution human activity, including oil spills , presents problem freshwater resources. largest petroleum spill has ever occurred in fresh water caused royal dutch shell tank ship in magdalena, argentina, on 15 january 1999, polluting environment, drinkable water, plants , animals.

fresh , unpolluted water accounts 0.003% of total water available globally.

agriculture

changing landscape use of agriculture has great effect on flow of fresh water. changes in landscape removal of trees , soils changes flow of fresh water in local environment , affects cycle of fresh water. result, more fresh water stored in soil benefits agriculture. however, since agriculture human activity consumes fresh water, can put severe strain on local freshwater resources resulting in destruction of local ecosystems. in australia, over-abstraction of fresh water intensive irrigation activities has caused 33% of land area @ risk of salination. regards agriculture, world bank targets food production , water management increasingly global issue foster debate.

limited resource

fresh water renewable , variable, finite natural resource. fresh water can replenished through process of water cycle, in water seas, lakes, forests, land, rivers, , reservoirs evaporates, forms clouds, , returns precipitation. locally however, if more fresh water consumed through human activities naturally restored, may result in reduced fresh water availability surface , underground sources , can cause serious damage surrounding , associated environments.

fresh water withdrawal

fresh water withdrawal quantity of water removed available sources use in purpose, excluding evaporation losses. water drawn off not entirely consumed , portion may returned further use downstream.

causes of limited fresh water

the increase in world population , increase in per capita water use puts increasing strains on finite resources avialability of clean fresh water world bank adds response freshwater ecosystems changing climate can described in terms of 3 interrelated components: water quality, water quantity or volume, , water timing. change in 1 leads shifts in others well. water pollution , subsequent eutrophication reduces availability of fresh water.

fresh water in future

many areas of world experiencing stress on water availability. due accelerated pace of population growth , increase in amount of water single person uses, expected situation continue worse. shortage of water in future detrimental human population affect sanitation, overall health , production of grain.

choices in use of fresh water

with 1 in 8 people in world not having access safe water important use resource in prudent manner. making best use of water on local basis provides best solution. local communities need plan use of fresh water , should made aware of how crops , animals use water.

as guide following tables provide indicators.

table 1 recommended basic water requirements human needs (per person)

table 2. water requirements of different classes of livestock

table 3 approximate values of seasonal crop water needs