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UGC NET Environmental Science Unit-IV: Environmental Geosciences Flashcards
67 question-and-answer cards covering Unit-IV: Environmental Geosciences as it is examined in UGC NET Environmental Science. 24 of them are printed below, taken from across the deck — no signup, no paywall on the preview.
24 sample cards from the Unit-IV: Environmental Geosciences deck
Sampled from the end of the deck, so these are different cards from the ones shown on the syllabus page.
What is the most abundant element in the bulk Earth (whole planet)?
Iron (~32%), followed by oxygen (~30%), silicon, and magnesium, because the dense Fe-rich core dominates the bulk composition.
What dissolved ions dominate the hydrosphere (seawater)?
Chloride (Cl-) and sodium (Na+) are dominant, along with sulfate, magnesium, calcium, and potassium; H and O make up the water itself.
What controls the partitioning of elements during surficial geologic processes?
Solubility, ionic potential (charge/radius), redox conditions (Eh), pH, and adsorption; soluble ions stay in solution while elements with high ionic potential form insoluble hydrolysates that concentrate in residues.
What is geochemical recycling of elements?
The continuous movement of elements among the crust, hydrosphere, atmosphere, and biosphere through weathering, erosion, sedimentation, subduction, volcanism, and uplift (biogeochemical cycling).
What is paleoclimate and name two proxies used to reconstruct it.
Paleoclimate is the climate of the geological past; proxies include ice cores (trapped gas and δ18O), ocean sediment/foraminifera oxygen-isotope ratios, tree rings, pollen, and corals.
How is water distributed on Earth among major reservoirs?
About 97% is saline ocean water; of the ~3% freshwater, most is locked in glaciers/ice caps (~69%), groundwater is ~30%, and surface water (lakes, rivers) is a small fraction (<1%).
State Darcy's law and define its terms.
Q = -K A (dh/dl): groundwater discharge Q equals hydraulic conductivity K times cross-sectional area A times the hydraulic gradient (dh/dl); the negative sign shows flow is from high to low head.
What is the validity limit of Darcy's law?
It is valid only for laminar (slow) flow, typically Reynolds number < 1-10; it breaks down for turbulent flow in coarse gravels/fractures and for very low gradients in dense clays.
What is hydraulic conductivity (K)?
A measure of an aquifer material's ability to transmit water under a hydraulic gradient (units m/day); it depends on both the medium's intrinsic permeability and the fluid's properties (density, viscosity).
What is the Ghyben-Herzberg relation?
In coastal aquifers, the depth of fresh-saltwater interface below sea level z ≈ 40 h, where h is the height of the freshwater table above sea level; i.e., for every 1 m of freshwater head, fresh water extends ~40 m below sea level.
What is land subsidence due to groundwater, and name an Indian example concern?
The gradual sinking of the land surface caused by compaction of aquifer sediments when excessive groundwater withdrawal reduces pore pressure; over-extraction in many Indian alluvial basins is a growing concern.
Name common effects of excessive groundwater use.
Declining water tables, land subsidence, drying of wells/springs, saltwater intrusion in coastal areas, deterioration of water quality, and increased pumping cost.
What are groundwater tracers used for?
Natural or artificial substances (dyes, isotopes like tritium/14C, salts) added to or measured in groundwater to determine flow direction, velocity, recharge age, and connectivity between aquifers.
What is the historical/conservation perspective on non-renewable resources?
Non-renewable resources (fossil fuels, minerals) form over geological timescales and are finite; conservation emphasizes efficient use, recycling, substitution by renewables, and equitable, sustainable exploitation to avoid depletion.
What environmental concerns arise from natural resource exploration and exploitation?
Habitat destruction, deforestation, soil erosion, water and air pollution, acid mine drainage, tailings/waste generation, land degradation, and displacement of communities.
List the major catastrophic geological hazards.
Floods, landslides, earthquakes, volcanism (volcanic eruptions), avalanches, tsunamis, and cloud bursts.
What is a tsunami and what commonly triggers it?
A series of long-wavelength ocean waves generated by sudden displacement of a large water volume, most often by submarine earthquakes, but also by undersea landslides or volcanic eruptions.
What is a cloud burst?
A sudden, very intense, localized rainfall event (conventionally >100 mm/hour) over a small area, often in mountainous terrain, that causes flash floods and landslides.
What is liquefaction in the context of earthquakes?
The process where saturated, loose granular soil temporarily loses strength and behaves like a liquid due to earthquake shaking, causing buildings to sink or tilt.
How are earthquake magnitude and intensity different?
Magnitude (Richter/moment scale) is an instrumental measure of the energy released at the source (single value); intensity (Mercalli scale) measures the observed effects/damage at a place and varies with distance.
Name common approaches to hazard prediction and mitigation.
Hazard mapping/zonation, early-warning systems, monitoring (seismic, weather, GPS), land-use planning/building codes, structural measures (dams, embankments), afforestation, public awareness, and emergency preparedness.
What are some major groundwater provinces/basins of India?
The Indo-Gangetic-Brahmaputra alluvial plains (most productive), the hard-rock Peninsular shield (Deccan basalts, crystalline rocks with limited fractured-zone storage), coastal sedimentary basins, and Cenozoic sedimentary tracts.
What is groundwater quality degradation and name common contaminants in India?
Deterioration of groundwater making it unfit for use; common Indian contaminants include fluoride, arsenic, nitrate, salinity, and iron, from geogenic sources and pollution.
How do tectonic and climatic controls jointly shape landforms?
Tectonics sets the elevation, rock type, and structural framework (uplift creating relief), while climate controls the dominant weathering/erosional processes (glacial, fluvial, aeolian, karst) that carve that relief into specific landform assemblages.
What this deck covers
The Unit-IV: Environmental Geosciences deck follows the UGC NET Environmental Science Unit-IV: Environmental Geosciences syllabus — 5 chapters and 27 topics — so questions land on material that is genuinely examinable rather than trivia around it. That works out to roughly 13.4 cards per chapter.
Answers are written to be recallable, not just readable — averaging about 189 characters, which is long enough to carry the reasoning and short enough to say out loud.
A deck like this earns its keep on the second and third pass. Read the syllabus first so you know the shape of the subject, then use the cards to find the specific facts that have not stuck.
Unit-IV: Environmental Geosciences flashcards FAQ
How many Unit-IV: Environmental Geosciences flashcards are in this UGC NET Environmental Science deck?
67 cards. This page previews 24 of them, sampled evenly across the deck so you can judge the difficulty before installing anything.
Are these UGC NET Environmental Science flashcards free?
Yes. The preview here is free to read with no signup, and the full 67-card deck is free inside the Examius app.
What do the Unit-IV: Environmental Geosciences cards cover?
They follow the UGC NET Environmental Science Unit-IV: Environmental Geosciences syllabus — 5 chapters and 27 topics — so the questions track what is actually examinable.
How should I use these flashcards?
Read the syllabus first so you know the shape of the subject, then drill the deck. Examius schedules each card with spaced repetition, so cards you keep missing come back sooner and ones you know drift further apart.