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  2. Biochemical oxygen demand - Wikipedia

    en.wikipedia.org/wiki/Biochemical_oxygen_demand

    BOD test bottles at the laboratory of a wastewater treatment plant. Biochemical oxygen demand (also known as BOD or biological oxygen demand) is an analytical parameter representing the amount of dissolved oxygen (DO) consumed by aerobic bacteria growing on the organic material present in a water sample at a specific temperature over a specific time period.

  3. Water balance - Wikipedia

    en.wikipedia.org/wiki/Water_balance

    [2] [3] In hydrology, a water balance equation can be used to describe the flow of water in and out of a system. A system can be one of several hydrological or water domains, such as a column of soil, a drainage basin, an irrigation area or a city. The water balance is also referred to as a water budget. Developing water budgets is a ...

  4. Infiltration (hydrology) - Wikipedia

    en.wikipedia.org/wiki/Infiltration_(hydrology)

    The maximum rate at that water can enter soil in a given condition is the infiltration capacity. If the arrival of the water at the soil surface is less than the infiltration capacity, it is sometimes analyzed using hydrology transport models, mathematical models that consider infiltration, runoff, and channel flow to predict river flow rates ...

  5. Streeter–Phelps equation - Wikipedia

    en.wikipedia.org/wiki/Streeter–Phelps_equation

    The model describes how dissolved oxygen (DO) decreases in a river or stream along a certain distance by degradation of biochemical oxygen demand (BOD). The equation was derived by H. W. Streeter, a sanitary engineer, and Earle B. Phelps, a consultant for the U.S. Public Health Service, in 1925, based on field data from the Ohio River. The ...

  6. Infiltration/Inflow - Wikipedia

    en.wikipedia.org/wiki/Infiltration/Inflow

    Infiltration/Inflow (I/I or I&I) is the process of groundwater, or water from sources other than domestic wastewater, entering sanitary sewers.I/I causes dilution in sanitary sewers, which decreases the efficiency of treatment, and may cause sewage volumes to exceed design capacity.

  7. Runoff curve number - Wikipedia

    en.wikipedia.org/wiki/Runoff_curve_number

    These soils have a very slow rate of water transmission (final infiltration rate less than 0.05 in (1.3 mm) per hour). Selection of a hydrologic soil group should be done based on measured infiltration rates, soil survey (such as the NRCS Web Soil Survey), or judgement from a qualified soil science or geotechnical professional. The table below ...

  8. Richards equation - Wikipedia

    en.wikipedia.org/wiki/Richards_equation

    The Richards equation represents the movement of water in unsaturated soils, and is attributed to Lorenzo A. Richards who published the equation in 1931. [1] It is a quasilinear partial differential equation; its analytical solution is often limited to specific initial and boundary conditions. [2]

  9. HBV hydrology model - Wikipedia

    en.wikipedia.org/wiki/HBV_hydrology_model

    The HBV hydrology model, or Hydrologiska Byråns Vattenbalansavdelning model, is a computer simulation used to analyze river discharge and water pollution. Developed originally for use in Scandinavia , [ 1 ] [ 2 ] [ 3 ] this hydrological transport model has also been applied in a large number of catchments on most continents.