Over 97% of the water on earth is unsuitable for human consumption due to its salinity. The vast majority (about 99%) of this is seawater, with most of the remainder consisting of saline groundwater (US Geological Survey, 2010). Purification of this saline water holds the promise of nearly unlimited water resources for human civilizations in coastal regions. However, purification of seawater is expensive, energy intensive and often has large adverse impacts on ecosystems. Despite these drawbacks, desalination can be an appropriate technological choice in certain settings.

Fogs have the potential to provide an alternative source of fresh water in dry regions and can be harvested through the use of simple and low-cost collection systems. Captured water can then be used for agricultural irrigation and domestic use. Research suggests that fog collectors work best in locations with frequent fog periods, such as coastal areas where water can be harvested as fog moves inland driven by the wind.

What is Soil Moisture Conservation Technique?

Rainfall can provide some of the cleanest naturally occurring water that is available. There is considerable scope for the collection of rainwater when it falls, before huge losses occur due to evaporation, transpiration, and runoff and drainage - before it becomes contaminated by natural means or man-made activities. Rainwater harvesting is a particularly suitable technology for areas where there is no surface water, or where groundwater is deep or inaccessible due to hard ground conditions, or where it is too salty or acidic.

Most precipitation that falls on human settlements is lost to the atmosphere through evapo-transporation (evaporation plus transpiration of water taken up by plants), or runs into rivers away from settlements before it can be used. In some water-rich regions, particularly wealthy regions with centralized water infrastructure, these losses may not be a major concern. However, in many water-poor areas, small-scale collection infrastructure can contribute greatly to the volume of freshwater available for human use.

Description

Water reallocation is the transfer of use rights between users who have been allocated a certain amount

of water (through formal water use rights or entitlements, or informal arrangements), after it has been

determined the initial allocation is physically impossible, or socioeconomically unfavourable. Resource

reallocation can help adapt to unforeseen circumstances (e.g. critical water shortages during the dry

season), reduce stress on renewable water supplies and help optimize water use benefits to meet