The following outline is provided as an overview of and topical guide to hydrology: Hydrology – study of the movement, distribution, and quality of water on Earth and other planets, including the hydrologic cycle, water resources and environmental watershed sustainability.
What type of thing is hydrology? Hydrology can be described as all of the following:
a branch of science a branch of natural science a branch of physical science a branch of Earth science a branch of geography a branch of physical geography
Essence of hydrology Water Hydrologic cycle Cryosphere Origin of water on Earth Water distribution on Earth
Branches of hydrology Hydrometry – the measurement of the different components of the hydrologic cycle Chemical hydrology – the study of the chemical characteristics of water Ecohydrology – the study of interactions between organisms and the hydrologic cycle Hydrogeology – the study of the presence and movement of water in aquifers Hydroinformatics – the adaptation of information technology to hydrology and water resources applications Hydrometeorology – the study of the transfer of water and energy between land and water body surfaces and the lower atmosphere Isotope hydrology – the study of the isotopic signatures of water Surface hydrology – the study of hydrologic processes that operate at or near the Earth's surface Catchment hydrology – study of the governing processes in a given hydrologically defined catchment Drainage basin management – covers water-storage, in the form of reservoirs, and flood-protection. Water quality – includes the chemistry of water in rivers and lakes, both of pollutants and natural solutes.
History of hydrology History of hydrology
Things studied by hydrology
Abstract concepts in hydrology Field capacity
Phenomena studied by hydrology
Water movement pathways Water cycle (aka "hydrological cycle")
Above ground Evaporation – Pan evaporation – Condensation – Precipitation – condensed water, is pulled by gravity back to Earth, in the form of: Drizzle Rain Sleet Snow Graupel Hail Interception – Evapotranspiration – Stemflow – Throughfall – On ground Surface runoff – flow of surface water First flush Floods Flash floods Overland flow – Horton overland flow – Below ground Infiltration – Pipeflow – Baseflow – Subsurface flow – flow of ground water
Physical things studied by hydrology Ground water Soil moisture Surface water
Environmental issues Desertification/Oasification – Hypoxia – Erosion – Water pollution –
Measurement tools
Groundwater Source:
Aquifer characterization Flow direction Piezometer - groundwater pressure and, by inference, groundwater depth (see: aquifer test) Conductivity, storativity, transmisivity Geophysical methods Vadose zone characterization Infiltration Infiltrometer - infiltration Soil moisture Capacitance probe-soil moisture Time domain reflectometer - soil moisture Tensiometer - soil moisture Solute sampling Geophysical methods
Surface water Source:
Water level Mechanical pressure gauge – Electronic pressure gauge – Acoustic pressure gauge – Channel shape Dumpy level – Discharge Acoustic Doppler velocimeter – Dilution tracing –
Meteorological Precipitation Rain gauge – rainfall depth (unit) and intensity (unit time−1) Disdrometer – raindrop size, total precipitation depth and intensity Doppler weather radar – raindrop size, total precipitation depth and intensity, rain cloud reflectivity converted to precipitation intensity through calibration to rain gauges Wind profiler – precipitation vertical and horizontal motion, vertical cross-section of reflectivity and typing Frozen precipitation (on ground) Pressure sensors – pressure, depth, and liquid water equivalent Acoustic sensors – pressure, depth, and liquid water equivalent Mean windspeed and direction Anemometer – Doppler sonar – Wind profiler – air vertical and horizontal motion Mean air temperature Thermometer – Humidity Infrared thermometer – a form of remote sensing Hygrometer (Psychrometer) – measures relative humidity Air pressure Barometer – Heat flux Net radiometer – Pyranometer – Pyrgeometer – Heat flux sensor – Lysimeter – Cloudiness/Sunshine Spectroradiometer – Campbell–Stokes recorder – Evapotranspiration Water budget method Basin water balance – Evaporation pan – Lysimetry – Soil moisture depletion – Water vapor transfer method Bowen ratio – considers the energy budget Eddy covariance – Component analysis Porometry/Sap flow – Interception loss – Soil evaporation – Large-scale Scintillometer – Remote sensing estimates – LIDAR –
Soil/porous media Source:
Bulk density & porosity Oven dried sample – Matric potential Suction plate – determines relationship between the water volume and matric potential Resistance thermometer – relates to matric potential from previous calibration Hydraulic conductivity Disc permeameter – measures soil hydraulic conductivity Rainfall simulator – measures output through the application of constant input ("rain") in a sealed area Slug test – addition or removal of water and monitors the time until return to predisturbance level Piezometer – Soil moisture content (water volume percentage) Frequency domain sensor – Time domain reflectometer – Neutron probe –
Water quality Source:
Conductivity Electrical conductivity – variety of probes used pH pH meter – Dissolved oxygen (DO) Winkler test – Turbidity Nephelometer (Turbidimeter) – Water clarity Secchi disk – Bed load Erosion/deposition
Modeling Behavioral modeling in hydrology
Equations Basin
Hack's law – Catchment
Water balance – Evaporation
Penman – Penman-Monteith – Infiltration/Soil Movement
Darcy's law – Darcy-Weisbach – Richards equation – Streamflow/Open channel
Fick's law of diffusion – Chézy formula – Manning formula – Strahler number – Standard step method – computational technique for modeling steady state open channel surface profiles Erosion
Hjulström curve – Groundwater
Dupuit–Forchheimer assumption – Groundwater flow equation –
Power/Uncertainty Nash–Sutcliffe model efficiency coefficient GLUE
Models Hydrological transport model
… excerpt ends here. Continue reading the full article.
