Distilled water is water that has been boiled into vapor and condensed back into liquid in a separate container. Impurities in the original water that do not boil below or near the boiling point of water remain in the original container. Thus, distilled water is a type of purified water. (Full article...)
An example of guttation, the appearance of drops of xylem sap on the tips or edges of leaves of some vascular plants, on an Equisetum. At night, transpiration usually does not occur because most plants have their stomata closed. When there is a high soil moisture level, water will enter plant roots, because the water potential of the roots is lower than in the soil solution. The water will accumulate in the plant creating a slight root pressure. The root pressure forces some water to exude through special leaf tip or edge structures, hydathodes, forming drops. Guttation is not to be confused with dew, which condenses from the atmosphere onto the plant surface.
An iceberg is a large piece of freshwater ice that has broken off a glacier or an ice shelf and is floating freely in the open sea. Because the sea around this iceberg is so calm, the underwater portion is visible through the clear water. The largest iceberg ever detected was B-15, which split from the Ross Ice Shelf in Antarctica in 2000, and had a flat top; it had a surface area of 11,000 km2 (4,200 sq mi) and broke into several pieces in 2002 and 2003. This picture depicts an irregularly shaped iceberg with a rounded top, calved from a glacier in the Arctic and photographed in the Arctic Ocean north of Svalbard.
A side-by-side comparison of the Aral Sea in 1989 and 2008, showing its severe shrinkage owing to poor water resource management. The Aral Sea was once the fourth-largest lake in the world. However, the rivers that fed it were diverted by Soviet-era irrigation projects. It had shrunk to 10% of its former size by 2007, and is still shrinking. The near-loss of the Aral Sea, which is now in Kazakhstan and Uzbekistan, has been considered one of the planet's most disastrous examples of poor environmental resource management.
Rain is an oil-on-canvas painting by Dutch painter Vincent van Gogh, part of The Wheat Field, a series that he executed in 1889 while a voluntary patient in the Saint-Paul asylum near Saint-Rémy-de-Provence, France. Through his cell window on the upper floor, he could see an enclosed wheat field, and he made about a dozen paintings of it over the changing seasons. In this work, he represented falling rain with diagonal lines of paint. The style is reminiscent of Japanese prints, but the effect is stylistically personal to Van Gogh. Seen through his rain-splattered window, he shows its bleak aspect in November, with grey clouds overhead and the wheat already harvested. The painting is now in the collection of the Philadelphia Museum of Art.
Image 11A view of the Rosoki River in the eponymous village, Macedonia
Plate XIX of "Studies among the Snow Crystals ... " by Wilson Bentley (1902), the first person known to photograph snowflakes. He did so by catching an individual snowflake on a blackboard, rushing it onto some black velvet, which he would then photograph using a bellows camera he had attached to a microscope. His first photograph of a snowflake was on January 15, 1885 and he would capture over 5000 images of crystals in his lifetime. Bentley also photographed all forms of ice and natural water formations including clouds and fog. He was the first American to record raindrop sizes and was one of the first cloud physicists.
The head of an impact sprinkler, a type of irrigation sprinkler in which the sprinkler head, driven in a circular motion by the force of the outgoing water, pivots on a bearing on top of its threaded attachment nut. Invented in 1935 by Orton Englehardt, it quickly found widespread use.
The Haditha Dam is an earth-filled dam in Iraq, holding back the waters of the Euphrates to create Lake Qadisiyah. The area around Haditha is very arid, with a hot desert climate; the annual precipitation is about 127 millimetres (5 in), mainly occurring during the winter. This photograph, taken from the International Space Station in November 2015, shows the reservoir at a low water level, surrounded by an expanse of dry lakebed; the Haditha Dam is visible near the top of the image. Lake Qadisiyah has a maximum water-storage capacity of 8.3 cubic kilometres (2.0 cu mi) and a maximum surface area of 500 square kilometres (190 sq mi). The associated hydroelectric power station is capable of generating 660 megawatts of electricity, and outlets at the foot of the dam can discharge 3,000 cubic metres (110,000 cu ft) of water per second for irrigation.
Image 19Waterfall Shypit (height 14 m), Mizhhiria Raion, Zakarpattia Oblast of western Ukraine
When a liquid drop impacts the surface of a liquid reservoir it can float, bounce, coalesce with the reservoir, or splash. A floating drop remains on the surface for several seconds. Drop bouncing can occur on perturbed liquid surfaces. If the drop is able to rupture the thin film of gas which separates it from the liquid reservoir, it can coalesce. Additionally, higher Weber number drop impacts produce splashing. In the splashing regime, the impacting drop creates a crater in the fluid surface, followed by a crown around the crater. Finally, a central jet, called the "Rayleigh jet" or "Worthington jet", protrudes from the center of the crater. If the impact energy is high enough, the jet rises to the point where it pinches off, sending one or more droplets upward out of the surface.
Image 22A fire hydrant in Alkmaar, the Netherlands. Fire hydrants are a source of water provided by most metropolitan communities to enable firefighters to tap into the municipal water supply to assist in extinguishing a fire.
Image 6Poverty often leads to unhygienic living conditions, as in this community in the Indian Himalayas. Such conditions promote contraction of diarrheal diseases, as a result of contaminated drinking water, poor sanitation and hygiene. (from Drinking water)
Image 7Mortality rate attributable to unsafe water, sanitation, and hygiene (WASH). (from Drinking water)
Image 8The solid/liquid/vapor triple point of liquid water, ice Ih and water vapor in the lower left portion of a water phase diagram. (from Properties of water)
Image 9Estimates of changes in water storage around the Tigris and Euphrates Rivers, measured by NASA's GRACE satellites. The satellites measure tiny changes in gravitational acceleration, which can then be processed to reveal movement of water due to changes in its total mass. (from Hydrology)
Image 22This paper clip is under the water level, which has risen gently and smoothly. Surface tension prevents the clip from submerging and the water from overflowing the glass edges. (from Properties of water)