Hydrology Chapter 1 Flashcards
What is hydrology?
The science of water, dealing with its occurrence, circulation, and distribution on Earth and in the atmosphere.
What are the two main categories of hydrology?
1) Scientific hydrology (theoretical and academic aspects)
2) Engineering hydrology (practical applications in engineering)
What are the key areas covered in engineering hydrology?
Assessment of water resources, analysis of precipitation, runoff, evapotranspiration, and study of floods, droughts, and mitigation strategies.
What is the hydrologic cycle?
A continuous process where water moves through evaporation, condensation, precipitation, infiltration, runoff, and storage.
What are the main processes in the hydrologic cycle?
Evaporation, condensation, precipitation, infiltration, runoff, and transpiration.
What is the water budget equation?
Mass inflow - mass outflow = change in mass storage
(Vi - Vo = ΔS), where Vi = inflow, Vo = outflow, and ΔS = change in storage.
What is an aquifer?
A water-bearing rock formation that can transmit water to wells and springs.
What is saltwater intrusion?
The process where saltwater enters freshwater aquifers, often due to over-pumping or sea-level rise.
How do human activities affect the hydrologic cycle?
Activities like deforestation, urbanization, and groundwater extraction alter precipitation patterns, infiltration, and runoff.
What is the world water balance?
The balance of evaporation and precipitation on a global scale, where excess precipitation over land leads to runoff into oceans.
What are common applications of hydrology in engineering?
Irrigation, water supply, flood control, hydropower, and navigation.
What are common sources of hydrological data?
Weather records, precipitation data, streamflow records, evaporation rates, soil infiltration properties, groundwater levels.
What is the runoff coefficient?
The ratio of runoff to precipitation, indicating how much rainfall contributes to surface runoff rather than infiltration or evaporation.
How is the residence time of water in a hydrologic phase calculated?
Residence time = Volume of water in phase ÷ Average flow rate in that phase.
What historical civilizations had knowledge of hydrology?
Indus Valley Civilization (3000 BC, wells and groundwater use), Ancient Egyptians (Nile River stage measurements), Vedic Period (early understanding of the hydrologic cycle).
What are common failures due to poor hydrological assessments?
Dam overtopping, bridge collapse due to floods, underestimated reservoir capacity.
What is the significance of probability in hydrology?
Hydrological events are analyzed statistically to predict extreme weather conditions and design resilient water structures.
