hydrology-example exam 1

What is the Definition of Hydrology? (3 pts)

occurrence distribution, movement, and properties of the waters and their relationship with the environment within each phase of the hydrological cycle

In class we mentioned 4 broad "Applications of Hydrology" (that is things you might be doing during your career as a hydrologist). List the 4 Applications (1 pt @ and give examples of each (2pts @)

water resource management: water balance, supply, and quality, irrigation, flood control

infrastructure design: dams, bridges, sewers, urban drainage

environment and scientific applications: geomorphic changes, contaminant transport, environmental policy, climate change

other applications: agricultural water balance, riparian zone restoration, landslide and drought risk

what is the hydrosphere and where is most water? freshwater?

depth to which water extends, ocean, galciers/groundwater

oldest structures and why

wooden neolithic well and fragments of ancient nilometers to measure river levels

other historical structures

water supply and drainage systems, purification of water using zeolites (porous mineral), nile and red sea connect by navigational canal, drilling of wells, irrigation and drainage, qanat system

renaissance scientists and what they did

leonardo da vinci (continuity equation to understand principles of water flow)
giovan fontana (understand floods and river improvements)

In the outside reading on the History of hydrology and in lecture it was noted that the 17th century hydrologists were the founders of experimental hydrology and established the principles of fundamental hydrology. List 3 of these scientists and tell me what they studied/found/accomplished (4pts @). Ultimately, what was the greatest achievement(s) of the century (hydrologically speaking)

benedetto castelli: published book (Delta misure dell’acque correnti) lead to universal acceptance of continuity equation
pierre perrault: show rainfall alone sufficient to support flow of springs and rivers throughout year (calc total rainfall in area of river and estimate discharge)
edme mariotte: experimentally proved rainfall sufficient for water flow (measure velocity and flow to estimate discharge)
edmond halley: evaporation pan experiment/calculations proved enough water evaporates to produce rainfall (completed missing part of hydrological cycle, found evaporation rate)

greatest achievement: acceptance of continuity equation and founding of experimental hydrology and principles of fundamental hydrology

19th century scientists and what they did

darcy (aspects of groundwater-darcys law (flow down gradient)
dupuit (well discharge equations using darcys law)
adolph thiem (confined and unconfined well, develop previous equaitons/law)

Hydrologic cycle (conceptual model). Draw a sketch of the hydrologic cycle (2pts)

powered by the sun evaporating/transpirating water from ocean or soil/plants, condensates, moves, precipitates, infiltration into percolation into groundwater, and runoff

describes flux of water between oceans, surface water bodies, groundwater in subsurface aquifers, the atmosphere, and biosphere.

List and define 5 processes of water movement/distribution that are part of the hydrologic cycle (2pts @)

precipitation: condensation of atmospheric water vapor that falls under gravity (rain, snow, sleet, hail, fog)
interception: rain caught by vegetation leads to transpiration
evapotranspiration: combines effect of evaporation (from ocean or soil) and transpiration (plants) into atmosphere as water vapor
infiltration: downward entry of water into soil, depends on soil properties
runoff: proportion of precipitation falling on area that is not absorbed, flowing into water bodies

Finally, what are 3 reasons the hydrologic cycle is so important (1 pt @). +more

all water bodies are connected, includes all earth’s water, if one gets polluted all are polluted, powered by the sun, closely tied to geologic processes

What is the water budget equation? (1 pt). Write it out and define all the variables (remember just the basic water budget equation).(9 pts).

simple, universal, and adaptable b/c it relies on few assumptions on mechanisms of water movement and storage

P(precipitation) + Qin (water flow into watershed, usually zero) = ET (evapotranspiration) + deltaS (change in water storage) + Qout(water flow out, equal to runoff)

Why is the water budget equation so important? (2pts).

gets you thinking about tracking of water inputs, outputs and storage (law of conservation and resource management)

List 3 applications of the water budget equation. (1pt@)

watershed and water resource management, agricultural irrigation, flood control, measure how precipitation contributes to water flow/bodies (water system, resource and management)

Drainage Basins!. What is the definition of a Drainage Basin.(2pts)

an area of land that contributes to a stream’s discharge at any given point along the stream (all water to common outflow point →watershed)

defines distribution of water resources, impacting, agriculture, drinking water supply, and hydropower generation

How does a drainage basin form? (3pts)

streams/rivers form valleys they occupy through erosion
deepening/downcutting, widening/lateral erosion, lengthening, deposition at mouth

Factors descriptive of a drainage-basin as related to its hydrology may be classified broadly as 5 different characteristics. List and describe these 5 factors? (2pts@)

morphologic: depend on topography of land forms that compose the drainage-basin and form and extent of stream-system or net-drainage
soil: describe materials forming the groundwork of drainage-basins, all physical properties involved in moisture-relation of soil
geologic-structural: depths and characteristics of underlying rocks and geologic structures and how they relate to groundwater or other hydrological conditions of drainage basins
vegetational: vegetation (natural or cultivated), growing within drainage basin
climate-hydrologic: temp, humidity, rainfall, and evaporation (as evaporate considered hydrologic: conditions dependent on hydrological cycle (specifically runoff/groundwater)

Book Question (Ch. 5.3).....Can you ever get enough watershed stuff? O.k. I know this will have some overlap... but still, the book asks an interesting question: What are the watershed factors that affect runoff. The text lists 7... tell me 5 of them (3pts@). Identify the watershed factor and tell me how it affects runoff. (Note: I want runoff specifically - the other Drainage Basin question dealt with all hydrologic characteristics).

drainage area size: understand the watershed and common outlet where runoff ends up
topography: certain topography effects flow of water/runoff (steeper=faster)
soil properties: impact the permeability of infiltration limiting/enhancing runoff
shape: circular fan have high rate runoff (diff source reach outlet at same time) than other (elongate) shapes
orientation: important for major slope face, effects soil and vegetation, runoff rate
geology: features and processes change land, different materials and elevation impact runoff rates (permeability, speed)
interflow: infiltration greater than rainfall; infiltration recharges soil water, and moves through the soil mantle toward the stream (lateral)