Water Resources question n answers graded A+ 2023/2024

Water ResourcesWatershed - correct answer An area or ridge of land that separates waters flowing to different rivers, basins, or seas. Unconfined aquifer - correct answer An unconfined aquifer, also called a water-table aquifer, is an aquifer which has the water table as its upper boundary. Unconfined aquifers occur near the ground surface. Confined aquifer - correct answer A confined aquifer is an aquifer that is bounded above and below by confining beds. Confined aquifers generally occur at significant depth below the ground surface. Hydraulic properties of aquifers. Aquifers store groundwater and transmit it toward a well or other point of discharge. Artesian well - correct answer If water reaches the ground surface under the natural pressure of the aquifer, the well is called a flowing artesian well. An aquifer is a geologic layer of porous and permeable material such as sand and gravel, limestone, or sandstone, through which water flows and is stored. Water table - correct answer Water table, also called Groundwater Table, upper level of an underground surface in which the soil or rocks are permanently saturated with water. The water table separates the groundwater zone that lies below it from the capillary fringe, or zone of aeration, that lies above it. Recharge zone - correct answer Recharge is the primary method that water enters an aquifer. This process usually occurs in the vadose zone below plant roots and is often expressed as a flux to the water table surface. Cone of depression - correct answer A cone of depression occurs in an aquifer when groundwater is pumped from a well. In an unconfined aquifer, this is an actual depression of the water levels. In confined aquifers, the cone of depression is a reduction in the pressure head surrounding the pumped well. Salt water intrusion - correct answer Saltwater intrusion is the movement of saline water into freshwater aquifers, which can lead to contamination of drinking water sources and other consequences. Saltwater intrusion occurs naturally to some degree in most coastal aquifers, owing to the hydraulic connection between groundwater and seawater. Subsidence - correct answer Subsidence is the motion of a surface as it shifts downward relative to a datum such as sea-level. The opposite of subsidence is uplift, which results in an increase in elevation. Ground subsidence is of concern to geologists, geotechnical engineers and surveyors. Floodplain - correct answer A floodplain or flood plain is an area of land adjacent to a stream or river that stretches from the banks of its channel to the base of the enclosing valley walls and experiences flooding during periods of high discharge. Oligotrophic lake - correct answer Characterized by a low accumulation of dissolved nutrient salts, supporting but a sparse growth of algae and other organisms, and having a high oxygen content owing to the low organic content. Mesotrophic lake - correct answer A lake is usually classified as being in one of three possible classes: oligotrophic, mesotrophic or eutrophic. Lakes with extreme trophic indices may also be considered hyperoligotrophic or hypereutrophic. Eutrophic lake - correct answer A eutrophic body of water, commonly a lake or pond, has high biological productivity. Due to excessive nutrients, especially nitrogen and phosphorus, these water bodies are able to support an abundance of aquatic plants. Usually, the water body will be dominated either by aquatic plants or algae. Impermeable surfaces - correct answer Permeable surfaces allow water to percolate into the soil to filter out pollutants and recharge the water table. Impermeable surfaces are solid surfaces that don't allow water to penetrate, forcing it to run off. Impermeable Surfaces. Permeable Surfaces. Asphalt. Levee - correct answer It regulates water levels. It is usually earthen and often parallel to the course of a river in its floodplain or along low-lying coastlines. Dike - correct answer A dike or dyke, in geological usage, is a sheet of rock that formed in a fracture in a pre-existing rock body. Dikes can be either magmatic or sedimentary in origin.