Erkin | April 5, 2013
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Water: Hydrologic cycle

The hydrologic cycle is a conceptual model that describes the storage and movement of water between the biosphere, atmosphere, lithosphere, and the hydrosphere (see Figure 1). Water on our planet can be stored in any one of the following major reservoirs: atmosphere, oceans, lakes, rivers, soils, glaciers, snowfields, and groundwater. Water moves from one reservoir to another by way of processes like evaporation, condensation, precipitation, deposition, runoff, infiltration, sublimation, transpiration, melting, and groundwater flow.

hydrocycle-hires

The oceans supply most of the evaporated water found in the atmosphere. Of this evaporated water, only 91% of it is returned to the ocean basins by way of precipitation. The remaining 9% is transported to areas over landmasses where climatological factors induce the formation of precipitation. The resulting imbalance between rates of evaporation and precipitation over land and ocean is corrected by runoff and groundwater flow to the oceans. Read more

Category: Article |
Erkin | April 2, 2013
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Robotic fish learns to navigate currents and turbulence in water

Robotic-fish-learns-to-navigate-currents-and-turbulence-in-waterThe goal of making robotic fish is to make them as functional as real fish but with the added sensors that humans want for detecting pollution, data about water, and so on.

But to get there, they need to have the sensors fish naturally have — including lateral line sensing. This is how fish detect and use flow features like currents in water.

Tallinn University of Technology reports, “Though flow is a highly volatile and unsteady state of matter, it can nonetheless be measured and characterized based on many salient features that do not change much in space and time (such as flow direction or turbulence intensity, for example)”. Read more

Category: Article |
Erkin | March 28, 2013
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The impact of climate change

RTEmagicC_facts_2degrees_01The IPCC predicts with high confidence that water stress will increase in central and southern Europe, and that by the 2070s, the number of people affected will rise from 28 million to 44 million. Summer flows are likely to drop by up to 80% in southern Europe and some parts of central and Eastern Europe. Europe’s hydropower potential is expected to drop by an average of 6%, but rise by 20–50% around the Mediterranean by 2070 (Alcamo et al., 2007).

The cost of adapting to the impacts of a 2°C rise in global average temperature could range from US$70 to $100 billion per year between 2020 and 2050 (World Bank, 2010). Of this cost, between US$13.7 billion (drier scenario) and $19.2 billion (wetter scenario) will be related to water, predominantly through water supply and flood management. Read more

Category: Facts and figures |
Erkin | March 26, 2013
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A resource without borders

Water is not confined to political borders. An estimated 148 states have international basins within their territory (OSU, n.d., 2008 data), and 21 countries lie entirely within them (OSU, n.d, 2002 data).

RTEmagicC_facts_basinsbycontThere are 276 transboundary river basins in the world (64 transboundary river basins in Africa, 60 in Asia, 68 in Europe, 46 in North America and 38 in South America).

185 out of the 276 transboundary river basins, about two-thirds, are shared by two countries. 256 out of 276 are shared by 2, 3 or 4 countries (92,7%), and 20 out of 276 are shared by 5 or more countries (7,2%), the maximum being 18 countries sharing a same transboundary river basin (Danube).

46% of the globe’s (terrestrial) surface is covered by transboundary river basins.

148 countries include territory within one or more transboundary river basins. 39 countries have more than 90% of their territory within one or more transboundary river basins, and 21 lie entirely within one or more of these watersheds. Read more

Category: Facts and figures |
Erkin | March 22, 2013
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An increasing demand

85% of the world population lives in the driest half of the planet.

RTEmagicC_facts_scarcitymap783 million people do not have access to clean water and almost 2.5 billion do not have access to adequate sanitation.

6 to 8 million people die annually from the consequences of disasters and water-related diseases.

Various estimates indicate that, based on business as usual, ~3.5 planets Earth would be needed to sustain a global population achieving the current lifestyle of the average European or North American.

Global population growth projections of 2–3 billion people over the next 40 years, combined with changing diets, result in a predicted increase in food demand of 70% by 2050. Read more

Category: Facts and figures |