Chapter 11 Groundwater question and correct answers 100% 2023/2024

Chapter 11 GroundwaterDescribe several ways in which groundwater can become contaminated. - correct answer 1. Pesticides and herbicides applied to agricultural crops can find their into groundwater. 2. Nitrate, formed from one of the most widely used fertilizers, is harmful in even small quantities in drinking water. 3. Rain can carry pollutants like toxic mercury and lead from city landfills into groundwater. 4. Liquid and solid wastes from septic tanks and sewage plants, as well as animal feedlots and slaughterhouses can contain bacteria, viruses, and parasites 5. Acid mine drainage form coal and metal mines can contaminate both surface and groundwater 6. Radioactive waste in shallow burial from the nuclear power industry 7. Also, naturally occurring minerals within rock and soil may contain elements such as arsenic, selenium, mercury, etc. Discuss the difference between porosity and permeability. - correct answer Porosity refers to the amount of open pore space in a given volume of rock or sediment. Permeability refers to the ability of a material to transmit a fluid through it. What is the water table? Is it fixed in position? - correct answer The water table marks the surface of the saturated zone and the separation of the saturated sone, in which all the rock openings are filled with water, to the unsaturated zone, or the zone where not all the sediment or rock openings are filled with water. It is not fixed position because.... What controls the velocity of of groundwater flow? - correct answer Permeability, the pressure of water within the saturated zone, and the elevation of water win the saturated zone. Name several geologic materials that make good aquifers. Define aquifer. - correct answer An aquifer is a body of saturated rock or sediment through which water can move easily. Aquifers are both highly permeable and saturated with water. Good aquifers include sandstone, conglomerate, well-jointed limestone, bodies of sand and gravel, and some fragmental or fractured volcanic rocks such as columnar basalt. What happens to the water table near a pumped well? - correct answer When water is pumped form a well, the water table is typically drawn down around the well into a depression shaped like an inverted cone known as a cone of depression. In turn, this lowers the water table around the region of the well. How does a confined aquifer differ from an unconfined aquifer? - correct answer An unconfined aquifer has a water table because it is only partly filled with water, and a confined aquifer is completely filled with water under pressure and is usually separated from the surface by a relatively impermeable confining bed. A confined aquifer is better for drinking water and agriculture because of its unpolluted water due to the impermeable barrier and slow recharge. Porosity is a. the percentage of a rock's volume that is openings c. the ability of of a sediment to retard water - correct answer a. the percentage of a rock's volume that is openings Permeability is - correct answer The capacity of a rock to transmit a fluid. The subsurface zone in which all rock openings are filled with water is called the - correct answer Saturated zone An aquifer is - correct answer A body of saturated rock or sediment through which water can move easily Which rock type would make the best aquifer? a. shale b. mudstone c. sandstone d. all of the preceding - correct answer c. sandstone Which of the following determines how quickly groundwater flows? a. elevation b. water pressure c. permeability d. all of the preceding - correct answer d. all of the preceding Groundwater flows a. always downhill b. from areas of high hydraulic head to low hydraulic head c. from high elevation to low elevation d. from high permeability to low permeability - correct answer b. from areas of high hydraulic head to low hydraulic head The drop in the water table around a pumped well is the a. drawdown b. hydraulic head c. porosity d. fluid potential - correct answer a. drawdown Gaining Streams - correct answer Receives water form the saturated zone ie. springs, lakes, streams, surface of stream coincides with water table. Losing Streams - correct answer Streams where the water eventually drains down to the water table at depth Groundwater - correct answer Groundwater is an essentially non renewable, slow recharge, natural resource that is 35x the amt of all the water in streams + lakes combined. Hydrolic Cycle - correct answer The circulation of water through the Earth-Atmosphere System... Atmospheric water from water vapor gas, clouds, and ice crystals precipitates onto the Earth's surface creating lakes streams, glaciers, vegetation,etc, and then infiltrates the interior, creating groundwater. Factors of Poor Infiltration - correct answer 1. heavy precipitation (only saturates surface) 2. steep slope (too much runoff)