USGS Water Science Glossary of Terms A | B | C | D | E | F | G | H | I | K | L | M | N | O | P | R | S | T | U | V | W | X | Y A acequia--acequias are gravity-driven waterways, similar in concept to a flume. Most are simple ditches with dirt banks, but they can be lined with concrete. They were important forms of irrigation in the development of agriculture in the American Southwest. The proliferation of cotton, pecans and green chile as major agricultural staples owe their progress to the acequia system. acid--a substance that has a pH of less than 7, which is neutral. Specifically, an acid has more free hydrogen ions (H+) than hydroxyl ions (OH-). acre-foot (acre-ft)--the volume of water required to cover 1 acre of land (43,560 square feet) to a depth of 1 foot. Equal to 325,851 gallons or 1,233 cubic meters.

alkaline--sometimes water or soils contain an amount of alkali (strongly basic) substances sufficient to raise the pH value above 7.0 and be harmful to the growth of crops. alkalinity--the capacity of water for neutralizing an acid solution. alluvium--deposits of clay, silt, sand, gravel, or other particulate material that has been deposited by a stream or other body of running water in a streambed, on a flood plain, on a delta, or at the base of a mountain. appropriation doctrine--the system for allocating water to private individuals used in most Western states. The doctrine of Prior Appropriation was in common use throughout the arid west as early settlers and miners began to develop the land. The prior appropriation doctrine is based on the concept of "First in Time, First in Right." The first person to take a quantity of water and put it to Beneficial Use has a higher priority of right than a subsequent user. Under drought conditions, higher priority users are satisfied before junior users receive water. Appropriative rights can be lost through nonuse; they can also be sold or transferred apart from the land. Contrasts with Riparian Water Rights.

aquaculture--farming of plants and animals that live in water, such as fish, shellfish, and algae. aqueduct--a pipe, conduit, or channel designed to transport water from a remote source, usually by gravity. aquifer--a geologic formation(s) that is water bearing. A geological formation or structure that stores and/or transmits water, such as to wells and springs. Use of the term is usually restricted to those water-bearing formations capable of yielding water in sufficient quantity to constitute a usable supply for people's uses. aquifer (confined)--soil or rock below the land surface that is saturated with water. There are layers of impermeable material both above and below it and it is under pressure so that when the aquifer is penetrated by a well, the water will rise above the top of the aquifer. aquifer (unconfined)--an aquifer whose upper water surface (water table) is at atmospheric pressure, and thus is able to rise and fall. artesian water--groundwater that is under pressure when tapped by a well and is able to rise above the level at which it is first encountered. It may or may not flow out at ground level.

The pressure in such an aquifer commonly is called artesian pressure, and the formation containing artesian water is an artesian aquifer or confined aquifer. See flowing well artificial recharge--an process where water is put back into groundwater storage from surface-water supplies such as irrigation, or induced infiltration from streams or wells. B base flow--sustained flow of a stream in the absence of direct runoff. It includes natural and human-induced streamflows. Natural base flow is sustained largely by groundwater discharges. base--a substance that has a pH of more than 7, which is neutral. A base has less free hydrogen ions (H+) than hydroxyl ions (OH-). bedrock--the solid rock beneath the soil and superficial rock. A general term for solid rock that lies beneath soil, loose sediments, or other unconsolidated material. C capillary action--the means by which liquid moves through the porous spaces in a solid, such as soil, plant roots, and the capillary blood vessels in our bodies due to the forces of adhesion, cohesion, and surface tension. Capillary action is essential in carrying substances and nutrients from one place to another in plants and animals.

commercial water use--water used for motels, hotels, restaurants, office buildings, other commercial facilities, and institutions. Water for commercial uses comes both from public-supplied sources, such as a county water department, and self-supplied sources, such as local wells. condensation--the process of water vapor in the air turning into liquid water. Water drops on the outside of a cold glass of water are condensed water. Condensation is the opposite process of evaporation . consumptive use--that part of water withdrawn that is evaporated, transpired by plants, incorporated into products or crops, consumed by humans or livestock, or otherwise removed from the immediate water environment. Also referred to as water consumed. conveyance loss--water that is lost in transit from a pipe, canal, or ditch by leakage or evaporation. Generally, the water is not available for further use; however, leakage from an irrigation ditch, for example, may percolate to a groundwater source and be available for further use. cubic feet per second (cfs)--a rate of the flow, in streams and rivers, for example. It is equal to a volume of water one foot high and one foot wide flowing a distance of one foot in one second.

One "cfs" is equal to 7.48 gallons of water flowing each second. As an example, if your car's gas tank is 2 feet by 1 foot by 1 foot (2 cubic feet), then gas flowing at a rate of 1 cubic foot/second would fill the tank in two seconds. D desalination--the removal of salts from saline water to provide freshwater. This method is becoming a more popular way of providing freshwater to populations. discharge--the volume of water that passes a given location within a given period of time. Usually expressed in cubic feet per second. domestic water use--water used for household purposes, such as drinking, food preparation, bathing, washing clothes, dishes, and dogs, flushing toilets, and watering lawns and gardens. About 85% of domestic water is delivered to homes by a public-supply facility, such as a county water department. About 15% of the Nation's population supply their own water, mainly from wells. drainage basin--land area where precipitation runs off into streams, rivers, lakes, and reservoirs.

It is a land feature that can be identified by tracing a line along the highest elevations between two areas on a map, often a ridge. Large drainage basins, like the area that drains into the Mississippi River contain thousands of smaller drainage basins. Also called a "watershed." drip irrigation--a common irrigation method where pipes or tubes filled with water slowly drip onto crops. Drip irrigation is a low-pressure method of irrigation and less water is lost to evaporation than high-pressure spray irrigation . drawdown--a lowering of the groundwater surface caused by pumping. E effluent--water that flows from a sewage treatment plant after it has been treated. erosion--the process in which a material is worn away by a stream of liquid (water) or air, often due to the presence of abrasive particles in the stream. estuary--a place where fresh and salt water mix, such as a bay, salt marsh, or where a river enters an ocean. evaporation--the process of liquid water becoming water vapor, including vaporization from water surfaces, land surfaces, and snow fields, but not from leaf surfaces. See transpiration evapotranspiration--the sum of evaporation and transpiration .

F flood--An overflow of water onto lands that are used or usable by man and not normally covered by water. Floods have two essential characteristics: The inundation of land is temporary; and the land is adjacent to and inundated by overflow from a river, stream, lake, or ocean. flood, 100-year--A 100-year flood does not refer to a flood that occurs once every 100 years, but to a flood level with a 1 percent chance of being equaled or exceeded in any given year. flood plain--a strip of relatively flat and normally dry land alongside a stream, river, or lake that is covered by water during a flood. flood stage--The elevation at which overflow of the natural banks of a stream or body of water begins in the reach or area in which the elevation is measured. floodway--The channel of a river or stream and the parts of the floodplain adjoining the channel that are reasonably required to efficiently carry and discharge the flood water or flood flow of a river or stream. flowing well/spring--a well or spring that taps groundwater under pressure so that water rises without pumping.

If the water rises above the surface, it is known as a flowing well. freshwater, freshwater--water that contains less than 1,000 milligrams per liter (mg/L) of dissolved solids; generally, more than 500 mg/L of dissolved solids is undesirable for drinking and many industrial uses. G gage height--the height of the water surface above the gage datum (zero point). Gage height is often used interchangeably with the more general term, stage, although gage height is more appropriate when used with a gage reading. gaging station--a site on a stream, lake, reservoir or other body of water where observations and hydrologic data are obtained. The U.S. Geological Survey measures stream discharge at gaging stations. geyser--a geothermal feature of the Earth where there is an opening in the surface that contains superheated water that periodically erupts in a shower of water and steam. giardiasis--a disease that results from an infection by the protozoan parasite Giardia Intestinalis, caused by drinking water that is either not filtered or not chlorinated.

The disorder is more prevalent in children than in adults and is characterized by abdominal discomfort, nausea, and alternating constipation and diarrhea. glacier--a huge mass of ice, formed on land by the compaction and recrystallization of snow, that moves very slowly downslope or outward due to its own weight. greywater--wastewater from clothes washing machines, showers, bathtubs, hand washing, lavatories and sinks. groundwater--(1) water that flows or seeps downward and saturates soil or rock, supplying springs and wells. The upper surface of the saturate zone is called the water table. (2) Water stored underground in rock crevices and in the pores of geologic materials that make up the Earth's crust. groundwater, confined--groundwater under pressure significantly greater than atmospheric, with its upper limit the bottom of a bed with hydraulic conductivity distinctly lower than that of the material in which the confined water occurs. groundwater recharge--inflow of water to a groundwater reservoir from the surface. Infiltration of precipitation and its movement to the water table is one form of natural recharge. Also, the volume of water added by this process.

groundwater, unconfined--water in an aquifer that has a water table that is exposed to the atmosphere. H hardness--a water-quality indication of the concentration of alkaline salts in water, mainly calcium and magnesium. If the water you use is "hard" then more soap, detergent or shampoo is necessary to raise a lather. headwater(s)--(1) the source and upper reaches of a stream; also the upper reaches of a reservoir. (2) the water upstream from a structure or point on a stream. (3) the small streams that come together to form a river. Also may be thought of as any and all parts of a river basin except the mainstream river and main tributaries. hydroelectric power water use--the use of water in the generation of electricity at plants where the turbine generators are driven by falling water. hydrologic cycle--the cyclic transfer of water vapor from the Earth's surface via evapotranspiration into the atmosphere, from the atmosphere via precipitation back to earth, and through runoff into streams, rivers, and lakes, and ultimately into the oceans. I impermeable layer--a layer of solid material, such as rock or clay, which does not allow water to pass through.

industrial water use--water used for industrial purposes in such industries as steel, chemical, paper, and petroleum refining. Nationally, water for industrial uses comes mainly (80%) from self-supplied sources, such as a local wells or withdrawal points in a river, but some water comes from public-supplied sources, such as the county/city water department. infiltration--flow of water from the land surface into the subsurface. injection well--refers to a well constructed for the purpose of injecting treated wastewater directly into the ground. Wastewater is generally forced (pumped) into the well for dispersal or storage into a designated aquifer. Injection wells are generally drilled into aquifers that don't deliver drinking water, unused aquifers, or below freshwater levels. irrigation--the controlled application of water for agricultural purposes through manmade systems to supply water requirements not satisfied by rainfall. Here's a quick look at some types of irrigation systems . irrigation water use--water application on lands to assist in the growing of crops and pastures or to maintain vegetative growth in recreational lands, such as parks and golf courses. K kilogram--one thousand grams.

kilowatthour (KWH)--a power demand of 1,000 watts for one hour. Power company utility rates are typically expressed in cents per kilowatt-hour. L leaching--the process by which soluble materials in the soil, such as salts, nutrients, pesticide chemicals or contaminants, are washed into a lower layer of soil or are dissolved and carried away by water. lentic waters--ponds or lakes (standing water). levee--a natural or manmade earthen barrier along the edge of a stream, lake, or river. Land alongside rivers can be protected from flooding by levees. livestock water use--water used for livestock watering, feed lots, dairy operations, fish farming, and other on-farm needs. lotic waters--flowing waters, as in streams and rivers. M maximum contaminant level (MCL)--the designation given by the U.S. Environmental Protection Agency (EPA) to water-quality standards promulgated under the Safe Drinking Water Act. The MCL is the greatest amount of a contaminant that can be present in drinking water without causing a risk to human health. milligram (mg)--One-thousandth of a gram.

milligrams per liter (mg/l)--a unit of the concentration of a constituent in water or wastewater. It represents 0.001 gram of a constituent in 1 liter of water. It is approximately equal to one part per million (PPM). million gallons per day (Mgd)--a rate of flow of water equal to 133,680.56 cubic feet per day, or 1.5472 cubic feet per second, or 3.0689 acre-feet per day. A flow of one million gallons per day for one year equals 1,120 acre-feet (365 million gallons). mining water use--water use during quarrying rocks and extracting minerals from the land. municipal water system--a water system that has at least five service connections or which regularly serves 25 individuals for 60 days; also called a public water system N nephelometric turbidity unit (NTU)--unit of measure for the turbidity of water. Essentially, a measure of the cloudiness of water as measured by a nephelometer. Turbidity is based on the amount of light that is reflected off particles in the water.

NGVD--National Geodetic Vertical Datum. (1) As corrected in 1929, a vertical control measure used as a reference for establishing varying elevations. (2) Elevation datum plane previously used by the Federal Emergency Management Agency (FEMA) for the determination of flood elevations. FEMA current uses the North American Vertical Datum Plane. NGVD of 1929--National Geodetic Vertical Datum of 1929. A geodetic datum derived from a general adjustment of the first order level nets of the United States and Canada. It was formerly called "Sea Level Datum of 1929" or "mean sea level" in the USGS series of reports. Although the datum was derived from the average sea level over a period of many years at 26 tide stations along the Atlantic, Gulf of Mexico, and Pacific Coasts, it does not necessarily represent local mean sea level at any particular place. non-point source (NPS) pollution--pollution discharged over a wide land area, not from one specific location. These are forms of diffuse pollution caused by sediment, nutrients, organic and toxic substances originating from land-use activities, which are carried to lakes and streams by surface runoff.

Non-point source pollution is contamination that occurs when rainwater, snowmelt, or irrigation washes off plowed fields, city streets, or suburban backyards. As this runoff moves across the land surface, it picks up soil particles and pollutants, such as nutrients and pesticides. O organic matter--plant and animal residues, or substances made by living organisms. All are based upon carbon compounds. osmosis--the movement of water molecules through a thin membrane. The osmosis process occurs in our bodies and is also one method of desalinating saline water. outfall--the place where a sewer, drain, or stream discharges; the outlet or structure through which reclaimed water or treated effluent is finally discharged to a receiving water body. oxygen demand--the need for molecular oxygen to meet the needs of biological and chemical processes in water. Even though very little oxygen will dissolve in water, it is extremely important in biological and chemical processes. P pH--a measure of the relative acidity or alkalinity of water. Water with a pH of 7 is neutral; lower pH levels indicate increasing acidity, while pH levels higher than 7 indicate increasingly basic solutions.

Bovine Petroglyphs at Jebel Maqla A FIRST TIME DISCOVERY – THE SPLIT ROCK On numerous websites and several video productions and books pertaining to the real Mt. Sinai being in Saudi Arabia, pictures as well as video can be seen of the Rock at Horeb, or the Split Rock, as it has been so named by the Caldwell’s. These pictures, video, and in some instances still shots from video, are the result of their personal discovery of this rock in 1992. (Prior to that no one knew that a rock with a clean split down the middle existed there in Midian). Their names have never appeared in connection with this discovery before because of the fact that they were still in Saudi Arabia conducting research. Now, for the first time on their website, they share the story of that discovery. FIELD REPORT- THE SPLIT ROCK By Penny Caldwell Copyright 2002 – All Rights Reserved On April 2nd 1992, Jim and I were hiking in the mountains in northwestern Saudi Arabia seeking to find a way up the western face of Jebel Maqla.

We had been out to the eastern side of the mountain twice before in an attempt to explore it and take photographs, but were almost immediately apprehended at gunpoint and sent away each time. Figuring that our only chance of getting down into the area inside that fence was from the other side of the mountain, we drove past the usual wadi systems that serve as passages between the peaks and found ourselves at last on the opposite side of the range. After winding our way between numerous rock outcroppings and smaller peaks which serve as what one could call foothills to the much higher mountains in the background, we entered a valley that was different from the usual terrain of the local landscape. Facing south looking down this corridor, we noticed right away that the valley floor was not comprised of the same crushed granite we had been accustomed to, but was that of a smooth granite, almost washed. This valley stretched north and south for about two miles, and dotted all throughout its length are what must literally be described as huge hills comprised of bare rounded granite rocks. These hills range in height from fifty to several hundred feet tall.

As we continued driving we came over a small knoll and there before us was an enormous such formation, with the exception of a singularly unique feature that separated its appearance from every other surrounding hill. Rising from the very top of this hundred foot high boulder hill there stood a massive rock in the dead center, with an even split right down the middle of it. It stood strangely upright with regard to the contour of the rest of these hills of boulders, which were almost without exception rounded in nature. The rock itself appeared to be at least forty-five to fifty feet tall, and we immediately parked the truck and got out to take a closer look. The Split Rock at Horeb from the North Hiking up to the base of the structure was no easy task over these large round rocks, but all along the way were smooth places that we realized must be channels where water had washed between them. We walked then in these channels upward and were able to come right to the base of the two huge slabs of granite that now loomed over us. Standing there we came to realize some factual evidences that were quite startling in their revelation. In the first place, erosion takes on a very distinct pattern on the granite in the region.

Most damage is done by heat, for this side of the Lawz range is the western front facing the Gulf of Aqaba, and the literal measurable rainfall here is less than one-half inch every year, and in some cases, up to ten years. The rainfall amounts rise substantially on the eastern side of the range because of the normal cycle of clouds forming as they pass over the mountains and rain falling on the opposite grounds. Therefore it was very odd that on this certain hill, deep channels were cut into the granite base, obviously by copious amounts of flowing water. Where had it come from? And not only that, but the signature of heat related erosion is the cracking of the granite, which leaves sharp, thin flakes all over the rock. This rock was cleanly split right down the middle and spaced widely enough so that I could easily walk right between the pieces. No evidence of the normal sharp flaking was to be found. Now we had a massive rock with a clean split, and smooth channels leading from the base of it all the way down to the granite floor below in front of us. Anticipation was rising that we’d found something quite out of the ordinary.

The Split Rock at Horeb As we followed the channels downward, the significance of the smooth granite floor also became obvious to us. In each of the mountain passes leading up to the Lawz range from the eastern side and down to the Gulf of Aqaba from the western side, the material of the surface ground is that of crushed granite. Having the benefit of many trips to this place behind us, we can with great assurance declare that this area at the base of the split rock is the only spot within the whole of the vicinity that the desert floor is not tiny broken down nodules of granite. We noticed right away that far below us in the granite were not only channels that appear to have been cut out by water, but various depressions where it looked as though water had pooled up all over the valley at some point in time. This is the only place where water could have gathered and stood, for in the surrounding crushed granite it would have been swallowed up almost immediately. We were becoming steadily more aware that something very unusual must have happened here at this place.

The channels clearly showing at the base of the Split Rock Hiking back down the front of the split rock to the ground level, and once again following the grooves that surely seemed to be cut by the flow of water, we saw another unusual rock directly below the whole formation. This rock was oblong and about eight to ten feet in length, with a very flat side facing upward. The flat top was broken only by a perfectly round hole approximately two feet in diameter, cleanly burned through the height of the boulder to the ground underneath it. Small rocks are stacked in a step-like fashion on the front side of this huge stone. These rocks had a surface patina that appears to have been caused by a direct heat source. In the vicinity of this huge rock are scattered archeological remains of stacked stones, all definitely man-made. Some are rounded and have the appearance of kilns, while others are much larger and are square in shape. It is absolute that many years ago, this site was marked by the visitation of many people who thought it important enough to leave their evidences behind in a sure manner.

Flat stone at the base of the Split Rock at Horeb OUR PERSONAL CONCLUSIONS From the moment we saw this gigantic sliced boulder sticking out like a sore thumb in the valley on the western slopes of Jebel al Lawz, we knew that it was something unique and special. In all the area, and in fact in all our travels throughout Arabia, we had never until then and have not since run across anything as odd as this rock. A particular story in the Book of Exodus comes to mind immediately: Ex 17:1-8 17:1 And all the congregation of the children of Israel journeyed from the wilderness of Sin, after their journeys, according to the commandment of the LORD, and pitched in Rephidim: and there was no water for the people to drink. 2 Wherefore the people did chide with Moses, and said, Give us water that we may drink. And Moses said unto them, Why chide ye with me? wherefore do ye tempt the LORD? 3 And the people thirsted there for water; and the people murmured against Moses, and said, Wherefore is this that thou hast brought us up out of Egypt, to kill us and our children and our cattle with thirst?

4 And Moses cried unto the LORD, saying, What shall I do unto this people? they be almost ready to stone me. 5 And the LORD said unto Moses, Go on before the people, and take with thee of the elders of Israel; and thy rod, wherewith thou smotest the river, take in thine hand, and go. 6 Behold, I will stand before thee there upon the rock in Horeb; and thou shalt smite the rock, and there shall come water out of it, that the people may drink. And Moses did so in the sight of the elders of Israel. 7 And he called the name of the place Massah, and Meribah, because of the chiding of the children of Israel, and because they tempted the LORD, saying, Is the LORD among us, or not? Here an incident is recorded describing Moses as taking his rod and striking a rock, and water coming forth from that rock to give drink to the children of Israel in their desert wanderings. Could evidence of this event still exist today? What is clear to us is that at this site, something completely out of the ordinary had to have taken place.

Every piece of evidence in and around this rock and the hill of boulders it sits upon points directly at the scriptures displayed above. In another series of verses we have an extraordinarily good description of the rock Moses struck and its surroundings. They read as follows: Ps 78:15-16 15 He clave the rocks in the wilderness, and gave them drink as out of the great depths. 16 He brought streams also out of the rock, and caused waters to run down like rivers. In looking at verse 15, we can ascertain much with regard to the physiology of the rock and the process by which it was split. "He clave": the Hebrew word here is baqa', meaning to cleave; generally, to rend, break, rip, or open. Further definitions explicitly detail this word to mean to cleave asunder, divide asunder, or rend asunder. The word cleave actually means to divide in pieces. ..."the rocks": interestingly enough, the Hebrew word here is tsuwr, which is not plural. It means a rock or a boulder, sometimes a cliff, or an edge, as precipitous.

..."as out of the great depths": the word for depths here is tehowm, which means a surging mass of water as an abyss. We could, by expanding these Hebrew definitions declare the verse as follows: "He divided the boulder asunder into pieces; and gave them drink from the surging mass of waters from the abyss". Our take on the process by which water was given from the rock is that Moses struck it, just as he was told to do. From deep within the earth under this monolithic rock sitting atop this boulder hill came a gushing geyser of water from an large aquifer well below the surface. You could picture it as one of the old time oil wells coming in, if you will. The pressure from this earth shaking release of the waters of the deep was forced upward and right through the boulder hill and found its way to the base of the big rock itself. The pressure building beneath that rock finally caused it to give way and the stream of water literally sliced that rock in two, as we see it today. The water actually did come "out of the rock itself". Verse 16 tells us directly that the rock spoken of here must be elevated.

"He brought streams also out of the rock, and caused waters to run down like rivers". "He brought also": the Hebrew word here is yatsa, meaning to go out. Further expansion of the definition is to break out, bring forth out & up, to issue out, to shoot forth from, and to spring out. ..."streams": the Hebrew word here is nazal, meaning to drip or shed by trickling, to cause to flood or gush out, to pour down, a running water, stream. ..."out of the rock": the Hebrew word for rock here is cela, meaning to be lofty, a craggy rock. ..." and caused waters to run down": the Hebrew word is yarad, meaning to descend, literally to go downwards to a lower region, to bring down abundantly, to let run down. ..."like rivers": the Hebrew word is nahar, meaning a stream. Once again, to bring all these expanded meanings to life we would have, "He brought forth, outward, upward, & shooting forth, rivers gushing from the lofty, craggy rock, and caused waters to go downwards, descending to the lower region abundantly like rivers".

The split rock in Saudi Arabia has been divided right down the middle. It is sitting high atop a boulder hill, and is thereby defined as being lofty and craggy. In other words, if your candidate for the rock that Moses struck is not elevated, it can't be the rock that the Scriptures so painstakingly describe. Beside that, this split rock shows evidence that much water indeed flowed from a source between the two slabs that remain. It gushed up from great depths below the surface, came up and actually split the rock itself, then bubbled up and cascaded downward in great streams. It came out from behind the rock and in front of the rock, and formed the deep gouges and channels that are so evident in our pictures. It gushed on down, smoothing the boulders below the split rock, and pooled up below the entire formation giving the children of Israel and their flocks an almost instantaneous freshwater lake, way down below the rock. Traditional sites for this rock and the event that took place there do not fit this Biblical description in any way whatsoever. In fact, if you look at them in the light of practicality, they don’t make any sense at all.

If a small trickle broke out of a rock such as the traditional one, the people and flocks out on the far edge of the group of up to a million would in fact die of thirst before enough water could be taken in a container to them. And how would you be able to water the flocks in such a manner? It just doesn’t fit. When we look at the Hebrew scriptures and the choice of words given, we do not get the picture that a small trickle daintily bubbled from an average field stone. We are given the picture of a huge boulder, high and lofty, craggy and elevated. We also must admit that an enormous quantity of water was caused to burst forth forcefully, and literal rivers and streams were formed by the copious amounts the Lord provided. This rock in Saudi Arabia fits the description perfectly. The whole nation and all their flocks and herds would have taken a drink at the same time as these gushing rivers ran down and filled in all the depressions in the valley below. By the way, the valley below this rock is unique to the area also. While almost all the surrounding areas are covered with a broken, crushed granite, below this rock it has all been blown away and is beautifully smooth.

We feel like the waters must have blown the loose granite granules completely away, forming pools and ponding the water all around. In light of all the descriptions given us by Scripture, it seems most likely to us that this rock in Saudi Arabia in the ancient land of Midian is indeed the very rock Moses is said to have struck that brought forth the life giving water. Groundwater Definitions - NYS Dept. of Environmental Conservation Groundwater Definitions Note: The following definitions are not for regulatory purposes. Aquifer: An underground geological formation able to store and yield water (see artesian, confined, and unconfined aquifers). Artesian (or confined) aquifer: exist where the groundwater is bounded between layers of impermeable substances like clay or dense rock. When tapped by a well, water in confined aquifers is forced up, sometimes above the land surface. Artesian well: A well tapping a confined (or artesian) aquifer. Water in the well rises above the top of the aquifer under artesian pressure, but does not necessarily reach the land surface. When a well in which the water level is above the land surface (see "Pontiometric surface"), a natural flow of water out of the well occurs.

When water flows above the land surface the well is defined as a flowing artesian well. Cone of depression: The zone around a well in an unconfined aquifer that is normally saturated, but becomes unsaturated as a well is pumped, leaving an area where the water table dips down to form a cone shape. The shape of the cone is influenced by porosity and the water yield or pumping rate of the well. The land surface overlying the cone of depression is referred to as the area of influence. Confining layer: Geologic material with little or no permeability or hydraulic conductivity. Water does not pass through this layer or the rate of movement is extremely slow. Decommissioning a well: An environmentally sound process of sealing a well that is no longer being used in order to prevent groundwater contamination and harm to people and animals. "Well abandonment" can be a synonymous term unless it is used to describe a situation in which the use of a well is discontinued and the well is ignored or improperly sealed. Drawdown: A lowering of the groundwater level caused by pumping. Groundwater: Water found in the spaces between soil particles and cracks in rocks underground located in the saturation zone. Cracks in rocks can be due to joints, faults, etc.

Groundwater is a natural resource that is used for drinking, recreation, industry, and growing crops. Hydraulic conductivity: a measure of a material's capacity to transmit water. It is independent of the thickness of that material. See "Transmissivity" for related definition. Another term for hydraulic conductivity is "coefficient of permeability". Impermeable layer: A layer of material (such as clay) in an aquifer through which water does not pass or passes extremely slowly. Induced recharge: The recharge to an aquifer that occurs when a pumping well creates a cone of depression that lowers an adjacent water table below the level of a stream or lake, causing the stream or lake to lose water to the adjacent groundwater aquifer. Infiltration: Flow of water from the land surface into the subsurface. Infiltration rate: The quantity of water that enters the soil surface in a specified time interval. Often expressed in volume of water per unit of soil surface area per unit of time. Karst: A geologic formation of irregular limestone deposits that dissolve to form sink holes, underground streams, and caverns. Groundwater Mining: Withdrawal (removal) of groundwater over a period of time that exceeds the recharge rate of the supply aquifer.

Also referred to as overdraft or mining the aquifer. Monitoring well: A non-pumping well, generally of small diameter, that is used to measure the elevation of a water table or water quality. A piezometer, which is open only at the top and bottom of its casing, is one type of monitoring well. Perched aquifer: Localized zone of saturation above the main water table created by a laterally limited layer of underlying impermeable material. Permeable/Permeability: Capable of transmitting water (porous rock, sediment, or soil); the rate at which water moves through rocks or soil. Permeable layer: A layer of porous material (rock or unconsolidated sediment); in an aquifer, the layer through which water freely passes as it moves through the subsurface. Pore space: Openings between geologic material found underground. Also referred to as void space or interstices. Porosity: The ratio of the volume of void or air spaces in a rock or sediment to the total volume of the rock or sediment. The capacity of rock or soil to hold water varies with the material. For example, saturated small grain sand contains less water than coarse gravel.

Potentiometric surface: The potential level to which water will rise above the water level in an aquifer in a well that penetrates a confined aquifer; if the potential level is higher than the land surface, the well will overflow. See "Artesian well" and "Confined aquifer". Pumping test: Evaluation of an aquifer by "stimulation" through controlled pumping and observing the aquifer's "response" (drawdown) in the production and observation wells. See NYSDEC protocol for pumping tests . Also "aquifer test". As opposed to "pump test" which measures the performance of a pump. Recharge: Water added to an aquifer. For example, when rainwater seeps into the ground. Recharge may occur artificially through injection wells or by spreading water over groundwater reservoirs. Recharge rate: The quantity of water per unit of time that replenishes or refills an aquifer. Saturated thickness: Total water-bearing thickness of an aquifer. Saturated zone: Located immediately below the unsaturated zone (see definition below) where the pores are totally saturated with water. Same as "groundwater".

Spring: The emergence of groundwater at the land surface, usually at a clearly defined point; it may flow strongly or just ooze or seep out. Transmissivity: A measure of the capability of the entire thickness of an aquifer to transmit water. In other words, it is product of hydraulic conductivity and aquifer thickness. Also "coefficient of transmissivity". Technically defined as the rate of flow at which water is transmitted through a unit width of the saturated thickness an aquifer under a unit hydraulic gradient. In the English Engineering system it is flow in gallons per minute through the vertical section of an aquifer one foot wide and extending the full saturated height of an aquifer under a hydraulic gradient of 1. Unconfined aquifers: An aquifer in which the water table is at or near atmosphere pressure and is the upper boundary of the aquifer. Because the aquifer is not under pressure the water level in a well is the same as the water table outside the well. Unsaturated zone: Located immediately below the land surface where the pores contain both water and air, but are not totally saturated with water. Plant roots can capture the moisture passing through this zone, but it cannot provide water for wells.

Also known as the unsaturated zone or vadose zone. Watershed: The land area from which surface runoff drains into a stream, channel, lake, reservoir, or other body of water. Also called a drainage basin, watersheds may encompass an area of millions of square miles or as little as a few acres. They are often considered to be more of a local definition. Wellhead Protection Area Water table: The top of an unconfined aquifer; indicates the level below which soil and rock are saturated with water. See "potentiometric surface" for definition of water level of confined aquifer. Well: A bored, drilled or driven shaft, or a dug hole whose depth is greater than the largest surface dimension and whose purpose is to reach underground water supplies to inject, extract or monitor water. Wellhead protection area: A protected surface and subsurface zone surrounding a well or well field supplying a public water system to keep contaminants from reaching the well water. Wetlands: Lands where water saturation is the dominant factor in determining the nature of soil development and the types of plant and animal communities. Other common names for wetlands are sloughs, ponds, and marshes. All definitions after The Groundwater Foundation.

Bureau of Water Resource Management Division of Water

Question: What name is given to the rock formations used as a source of water?
Answer: Aquifers