Seep (hydrology)A seep or flush is a moist or wet place where water, usually groundwater, reaches the earth's surface from an underground aquifer. Seeps are usually not of sufficient volume to be flowing beyond their immediate above-ground location. They are part of the limnology-geomorphology system. Like a higher volume spring, the water is only from underground sources. Seeps mostly occur in lower elevation areas because water runs downhill, but can happen higher up if the groundwater present is abundant enough.
EastEast is one of the four cardinal directions or points of the compass. It is the opposite direction from west and is the direction from which the Sun rises on the Earth. As in other languages, the word is formed from the fact that east is the direction where the Sun rises: east comes from Middle English est, from Old English ēast, which itself comes from the Proto-Germanic *aus-to- or *austra- "east, toward the sunrise", from Proto-Indo-European *aus- "to shine," or "dawn", cognate with Old High German *ōstar "to the east", Latin aurora 'dawn', and Greek ἠώς ēōs 'dawn, east'.
Proportional symbol mapA proportional symbol map or proportional point symbol map is a type of thematic map that uses map symbols that vary in size to represent a quantitative variable. For example, circles may be used to show the location of cities within the map, with the size of each circle sized proportionally to the population of the city. Typically, the size of each symbol is calculated so that its area is mathematically proportional to the variable, but more indirect methods (e.g., categorizing symbols as "small," "medium," and "large") are also used.
Buffer stripA buffer strip is an area of land maintained in permanent vegetation that helps to control air quality, soil quality, and water quality, along with other environmental problems, dealing primarily on land that is used in agriculture. Buffer strips trap sediment, and enhance filtration of nutrients and pesticides by slowing down surface runoff that could enter the local surface waters. The root systems of the planted vegetation in these buffers hold soil particles together which alleviate the soil of wind erosion and stabilize stream banks providing protection against substantial erosion and landslides.
Isotope hydrologyIsotope hydrology is a field of geochemistry and hydrology that uses naturally occurring stable and radioactive isotopic techniques to evaluate the age and origins of surface and groundwater and the processes within the atmospheric hydrologic cycle. Isotope hydrology applications are highly diverse, and used for informing water-use policy, mapping aquifers, conserving water supplies, assessing sources of water pollution, and increasingly are used in eco-hydrology to study human impacts on all dimensions of the hydrological cycle and ecosystem services.
United States Geological SurveyThe United States Geological Survey (USGS), founded as the Geological Survey, is an agency of the United States government whose work spans the disciplines of biology, geography, geology, and hydrology. The agency was founded on March 3, 1879, to study the landscape of the United States, its natural resources, and the natural hazards that threaten it. The agency also makes maps of extraterrestrial planets and moons based on data from U.S. space probes.
1973–1975 recessionThe 1973–1975 recession or 1970s recession was a period of economic stagnation in much of the Western world during the 1970s, putting an end to the overall post–World War II economic expansion. It differed from many previous recessions by involving stagflation, in which high unemployment and high inflation existed simultaneously. Among the causes were the 1973 oil crisis, the deficits of the Vietnam War under President Johnson, and the fall of the Bretton Woods system after the Nixon shock.
Geochemical cycleIn Earth science, a geochemical cycle is the pathway that chemical elements take in the surface and crust of the Earth. The term "geochemical" tells us that geological and chemical factors are all included. The migration of heated and compressed chemical elements and compounds such as silicon, aluminium, and general alkali metals through the means of subduction and volcanism is known in the geological world as geochemical cycles. The geochemical cycle encompasses the natural separation and concentration of elements and heat-assisted recombination processes.
Water towerA water tower is an elevated structure supporting a water tank constructed at a height sufficient to pressurize a distribution system for potable water, and to provide emergency storage for fire protection. Water towers often operate in conjunction with underground or surface service reservoirs, which store treated water close to where it will be used. Other types of water towers may only store raw (non-potable) water for fire protection or industrial purposes, and may not necessarily be connected to a public water supply.
Drawdown (hydrology)In hydrology, there are two similar but distinct definitions in use for the word drawdown: In subsurface hydrogeology, drawdown is the reduction in hydraulic head observed at a well in an aquifer, typically due to pumping a well as part of an aquifer test or well test. In surface water hydrology and civil engineering, drawdown refers to the lowering of the surface elevation of a body of water, the water table, the piezometric surface, or the water surface of a well, as a result of the withdrawal of water.
