Water Resources and Its Types in Ecology

In this water resources and its types in ecology post we have briefly explained about freshwater resources, sea water, ground and surface water.

Freshwater Resources and Its Types in Ecology

Freshwater resources are vital and precious commodity, is essential for multiplicity of purposes, viz., drinking, agriculture, power generation, transportation and waste disposal.

In chemical processes industrial water is used as a reaction medium, a solvent, a scrubbing medium and a heat transfer agent. As a source of life for man, plants and animals, freshwater resources is indispensable and cannot be replaced by any other solvent.

The water cycle is used to calculate renewable water resources. They depict the long-term average yearly flow of rivers (surface water) and groundwater in this study. Groundwater bodies (deep aquifers) with a minimal rate of recharge on a human time scale are considered non-renewable water resources.

Availability of Water

The chief sources of freshwater resources are rain water, sea water, ground and surface water. The World’s total quantum of water is 140 x 1016 m3.

Water Resources

Freshwater Resources and Its Types in Ecology

Sea Water

The oceans contain over 97 percent of the world’s water supply, which is unfit for human consumption (not an freshwater resources) or other uses due to excessive salt concentration. 2.3 percent of the remaining 3% is trapped in the polar ice caps and hence inaccessible. Freshwater resources makes up the remaining 0.7 percent. If all of the sea beds could be lifted to the same level as the earth’s surface, the whole water in the seas would cover the entire earth’s surface, creating 2.5-kilometer-deep water mass.

Ground Water

Ground water freshwater resources, a natural gift, is roughly 210×109 m3 (0.66%) (0.66 percent) when infiltration, seepage, and evapotranspiration are included in. Nearly a third of this is used for irrigation, industrial, and domestic purposes, while the rest is recycled into rivers.

About 90% of the freshwater resources beneath the surface meets the definition of ground water. In the unsaturated zone above the water table, about 2% of water exists as soil moisture, which is crucial for plant growth.

The majority of the freshwater resources that enters the earth crust (about 165 x 1010 m3) is maintained as soil moisture. Only 500 x109 m 3 of water percolates to the groundwater deposits.

Water sprayed to agricultural fields travels down to the ground water table in the amount of 120 x109 m3, with 50 x109 m3 of surface flow also ending up as ground water. As a result, 670 x109 m3 of fresh water enters the earth each year.

Surface Water

We have a very limited stock of usable water that is, 0 03% of the mass balance. The 115×1010 m 3 of surface water an freshwater resources is increased by the addition of about 450 x109 m3 of fresh water from ground water flow, 200 x109 m3 from surface flow and 50 x 109 m3 as run-off from irrigated areas.

The surface loses almost 50×109 m3 m of its water which percolates down to ground water deposits. The total surface flow per year is 185×109 m3 which is distributed among river basins.

Rain Water

In India, the annual rainfall an freshwater resources is about 400 x1010 m2. Out of this, 70 x1010 m2 of water evaporates immediately, 115 x1010 m2 runs off into surface water bodies and the remaining percolates into the soil.

The hydrological cycle in nature is, more or less, balanced in terms of charge (cloud formation) and discharge (rainfall). By 2010, the total water requirement was expected to thrice as much as we had in 1974.

Water Quality

It is essential to enforce water quality standards to specify suitability of water for drinking, irrigation, industry, public health and environmental safety purposes. All developed countries strictly conform to water quality standards.

The United States Public Health (USPH) has laid down following standards for drinking water. The quality parameters for surface water (rivers, lakes, ponds) are 4 to 5 times higher than the above values for drinking water.

The delicate balance existing between the ratio of available and exploitable water resources and sustaining their quality should be maintained to support the life systems on earth.

Further Readings

Reference