Water resources

Water resources

type of natural resource

Subclass of	natural resource
Ein location	hydrosphere
Made from material	water

Water resources be natural resources of water wey potentially be useful give humans, for example as a source of drinking water supply anaa irrigation water. Dese resources fi be either freshwater from natural sources, anaa water dem produce artificially from oda sources, such as from reclaimed water (wastewater) anaa desalinated water (seawater). 97% of de water for Earth be salt water den three percent per be fresh water; slightly over two-thirds of dis be frozen insyd glaciers den polar ice caps. De remaining unfrozen freshwater be found mainly as groundwater, plus only a small fraction present above ground anaa insyd de air. Natural sources of fresh water dey include frozen water, groundwater, surface water, den under river flow. People dey use water resources for agricultural, household, den industrial activities.

Water resources be under threat from multiple issues. Der be water scarcity, water pollution, water conflict den climate change. Fresh water be in principle a renewable resource. However, de world ein supply of groundwater be steadily decreasing. Groundwater depletion (anaa overdrafting) dey occur for example insyd Asia, South America den North America.

Natural sources of fresh water

Further information: Water distribution on Earth

Natural sources of fresh water include surface water, under river flow, groundwater den frozen water.

Surface water

Main article: Surface water

Lake Chungará den Parinacota volcano insyd northern Chile

Surface water be water insyd a river, lake, anaa fresh water wetland. Surface water be naturally replenished by precipitation den naturally lost through discharge to de oceans, evaporation, evapotranspiration, den groundwater recharge. De only natural input to any surface water system be precipitation within its watershed. De total quantity of water insyd dat system at any given time be sanso dependent on chaw oda factors. These factors include storage capacity insyd lakes, wetlands den artificial reservoirs, de permeability of de soil beneath these storage bodies, de runoff characteristics of de land insyd de watershed, de timing of de precipitation den local evaporation rates. All of these factors sanso affect de proportions of water loss.

Humans often increase storage capacity by constructing reservoirs den decrease am by draining wetlands. Humans often increase runoff quantities den velocities by paving areas den channelizing de stream flow.

Natural surface water fit be augmented by importing surface water from anoda watershed through a canal anaa pipeline.

Brazil be estimated to have de largest supply of fresh water insyd de world, followed by Russia den Canada.

• 
  Panorama of a natural wetland (Sinclair Wetlands, New Zealand)

Water from glaciers

Glacier runoff be considered to be surface water. De Himalayas, wich are often bell "De Roof of de World", contain sum of de most extensive den rough high altitude areas on Earth as well as de greatest area of glaciers den permafrost outside of de poles. Ten of Asia's largest rivers flow from there, den more than a billion people's livelihoods depend on dem. To complicate matters, temperatures there are rising more rapidly than de global average. Insyd Nepal, de temperature has risen by 0.6 degrees Celsius over de last decade, whereas globally, de Earth has warmed approximately 0.7 degrees Celsius over de last hundred years.

Groundwater

Relative groundwater travel times in the subsurface

This section is an excerpt from Groundwater.[edit]

Water resources

type of natural resource

Subclass of	natural resource
Ein location	hydrosphere
Made from material	water

Groundwater be de water present beneath Earth ein surface insyd rock den soil pore spaces den insyd de fractures of rock formations. About 30 percent of all readily available fresh water insyd de world be groundwater. A unit of rock anaa an unconsolidated deposit be bell an aquifer wen e fit yield a usable quantity of water. De depth at wich soil pore spaces anaa fractures den voids insyd rock cam be completely saturated plus water dem dey bell de water table. Groundwater be recharged from de surface; e fi discharge from de surface naturally at springs den seeps, den fit form oases anaa wetlands. Groundwater sanso often be withdrawn for agricultural, municipal, den industrial use by constructing den operating extraction wells. De study of de distribution den movement of groundwater be hydrogeology, dem sanso bell groundwater hydrology.

Typically, groundwater be thought of as water wey dey flow thru shallow aquifers, buh, insyd de technical sense, e sanso fi contain soil moisture, permafrost (frozen soil), immobile water insyd very low permeability bedrock, den deep geothermal anaa oil formation water. Groundwater be hypothesized to provide lubrication dat fit possibly influence de movement of faults. E be likely dat much of Earth ein subsurface dey contain sum water, wich fi be mixed plus oda fluids insyd sum instances.

Under river flow

Throughout de course of a river, de total volume of water transported downstream will often be a combination of de visible free water flow together plus a substantial contribution flowing through rocks den sediments dat underlie de river den its floodplain called de hyporheic zone. For many rivers insyd large valleys, dis unseen component of flow may greatly exceed de visible flow. De hyporheic zone often forms a dynamic interface between surface water den groundwater from aquifers, exchanging flow between rivers den aquifers dat may be fully charged anaa depleted. Dis be especially significant insyd karst areas where pot-holes den underground rivers are common.

External links

• Renewable water resources in the world by country
• Portal to international hydrology and water resources
• Sustainable Sanitation and Water Management Toolbox