What causes shortage of water? 1.seasonal or annual precipitation 2.over-exploitation of the sources of water 3.contamination of the sources of water
4.all of the above

Explanation:

Water scarcity

Water scarcity is the lack of sufficient available water resources to meet the demands of water usage within a region.

It already affects every continent and around 2.8 billion people around the world at least one month out of every year.

More than 1.2 billion people lack access to clean drinking water.

Water scarcity involves water stress, water shortage or deficits, and water crisis.

While the concept of water stress is relatively new, it is the difficulty of obtaining sources of fresh water for use during a period of time and may result in further depletion and deterioration of available water resources.Water shortages may be caused by climate change, such as altered weather patterns including droughts or floods, increased pollution, and increased human demand and overuse of water.

A water crisis is a situation where the available potable, unpolluted water within a region is less than that region's demand.

Water scarcity is being driven by two converging phenomena: growing freshwater use and depletion of usable freshwater resources.

Water scarcity can be a result of two mechanisms: physical (absolute) water scarcity and economic water scarcity, where physical water scarcity is a result of inadequate natural water resources to supply a region's demand, and economic water scarcity is a result of poor management of the sufficient available water resources.

According to the United Nations Development Programme, the latter is found more often to be the cause of countries or regions experiencing water scarcity, as most countries or regions have enough water to meet household, industrial, agricultural, and environmental needs, but lack the means to provide it in an accessible manner.

The reduction of water scarcity is a goal of many countries and governments.

The UN recognizes the importance of reducing the number of people without sustainable access to clean water and sanitation.

The Millennium Development Goals within the United Nations Millennium Declaration state that by 2015 they resolve to "halve the proportion of people who are unable to reach or to afford safe drinking water."

Note: The above text is excerpted from the Wikipedia article "Water scarcity", which has been released under the GNU Free Documentation License.

uses : -

1.aneroid barometers primarily measure whether pressure is rising or falling.

2.aneroid barometers are often used for reading pressure in homes and recreational boats.  

3.other uses may include barographs in meteorology and altimeters in modern aircraft.  

4.this type of barometer can announce whether a high or low pressure system is coming or whether it is becoming more intense.  

5.there are different types of aneroid barometers, such as the altimeter, which measures altitude, or distance above sea level.  

6.another example is a barograph, which is a modified aneroid barometer that provides constant readings of atmospheric pressure on graph paper.  

7.when used in this capacity, the aneroid barometer can store a week's worth of data.

android diameter a device for measuring atmospheric pressure , often specially calibrated for use as an altimeter ,consisting of a box or chamber partially exhaused of air, having an elastic top and a pointer to indicate the degree of compression of the top caused by the external air

refer to the attachment for the characteristics : -