Albedo: the ratio of light reflected by a planet, or surface in general, to that received by it [<<LL whiteness equiv. to alb(us) white + edo n. suffix, as in torpedo]


Alluvium (-al): “ deposits of clay, silt, sand, gravel, or other particulate material that has been deposited by a stream, on a floodplain, delta or at the base of a mountain. . . . Because alluvium is transported by water, it is sorted by size and weight by the water volume and velocity. Fast moving streams can transport larger sediments such as gravel and cobbles.  When the stream velocity becomes very slow even the fine sediments such as silts and clays are deposited.” (Zaimes and Emanuel 2006)


Anadromy (-mous): reproductive behavioral pattern wherein fish migrate from the ocean up a (typically natal) freshwater river or stream to spawn in headwaters zones [< Gk anadromos running upward]


Appellation: the name or title by which someone is known. Mark Twain is the famous appellation by which everyone remembers author and humorist Samuel Clemens.  An appellation is what people call a person or thing — essentially, its name or title. George Herman Ruth’s parents may have known him as George, but the rest of the world knew this famous slugger by his appellation, Babe. If you use the word appellation in a discussion of wine, you’d mean the name of the region or vineyard where the wine originated. Champagne is an appellation for the bubbly white wine that comes from the Champagne region of France.  (  Note: wine appellations have legal force.


Aquifer: “a saturated permeable geologic formation which can yield significant quantities of water to wells and springs” (Ponce 2007)     Confined aquifer: a saturated permeable geologic formation bounded by substrates of lower permeability; for example, one composed of coarse alluvial sediments, such as sand and gravel, under- and/or overlain by fine-textured sediments such as clay or silt, through which groundwater flux is differentially restricted.  Compare with unconfined or unconsolidated aquifer.  Unconfined or unconsolidated aquifer: a saturated permeable geologic formation composed of highly porous (loosely packed, thus typically coarser-textured) sediments that permit relatively rapid groundwater flux.  Compare with confined aquifer.


Baseflow: “the flow of perennial streams . . . , consisting of interflow and groundwater flow intercepted by the stream” (Ponce 1989b); “the fraction of streamflow that originates in ground water” (Ponce 2007)


Baseflow augmentation: “Temporary storage of subsurface water in floodplains, streamsides, streambanks and/ or streambottom during the wet season, either by natural or artificial means, for later release during the dry season to increase the magnitude and permanence of low flows. The streamflow-regulating mechanism of streambank storage can shave floodpeaks and lead to net increases in summer flows” (Ponce 1989a).  More generally: enhancing and prolonging the storage of precipitation in the biosphere and upper levels of the lithosphere including the vadose zone (transitional soil layers), strategically, so that some portion of that stored water will eventually be yielded to surface waters, where it can provide for “beneficial uses”, as defined in water policy.


Capillary (water, pore space, action, etc): “water of specific retention” (Hursh and Fletcher1942); that is, water held in such minute passageways (micropores) that adhesion, cohesion and related physical forces outweigh the force of gravity on it, though it remains available to plants and other soil organisms.  See soil water.


Capillary fringe: “ located immediately above the water table. Water is held in this fringe by capillarity, at moisture levels close to saturation. However, the capillary fringe differs from the saturated zone in that a well will fill with water only to the base of the capillary fringe, i.e., the water table. Water in the capillary fringe is referred to as capillary water to distinguish it from water in the saturated zone, or groundwater proper” (Ponce 1989b).  It is considered part of the vadose, or unsaturated zone (ibid.)


Catchment or catchment area: drainage basin—a topographically defined unit of land through which precipitation not evaporated or transpired flows through a common outlet to the ocean or other receiving body.  Outside of North America, this term represents what North Americans refer to more generally as watershed (Hynes 1983).


Detention: temporary storage of water.  Below ground, soil water drainage by gravity is slowed, though not stopped, in macropores.  Above ground, runoff is slowed by semipermeable means — most typically by routing through soil, but other means are possible.


Ecohydrology: the science that “studies the interplay between water resources and ecosystems” (Daly and Porporato 2005)


Emergence (-ent): “a process by which a [self-organizing] system of interacting elements acquires qualitatively new pattern and structure that cannot be understood simply as the superposition of the individual contributions. Although the term may suggest that something mysteriously or magically materializes within the system, this is not the case.  The human mind is generally poor at predicting the properties of systems that consist of multiple components with complex, dynamic interactions. Thus, even if one has a full knowledge of the system’s elements and their mode of interaction, the collective properties of a selforganizing system often seem to arise unexpectedly.” (Camazine 2003)  See self-organizing systems.


Fractal: Benoit Mandelbrot “coined fractal from the Latin adjective fractus . . . meaning ‘to break’; to create irregular fragments . . . a rough or fragmented geometric shape that can be split into parts, each of which is [approximately] a reduced-size copy of the whole” (Mandelbrot 1982); that is, a structure and/or system exhibiting approximate self-similarity at different scales; fractals express nature’s irregular geometry, contrasting with the regular shapes of Euclidian geometry; Fractal dimensions are fractional dimensions: between 1- and 2-, or 2- and 3- dimensions, e.g., Cantor Set: 0.63, Koch Snowflake: 1.26, and Menger Sponge: 2.73 (Garcia 1991);


Fractal interfaces are highly irregular, “fuzzy”, natural boundaries whose lengths or surface areas fragment and increase upon examination at closer scales, e.g., the boundaries among water, air and land along coastlines, or the boundaries among the biosphere, hydrosphere, lithosphere and even atmosphere that comprise soil


Glomalin: a.k.a. glomalin-related soil protein, a soil protein class associated with mycorrhizas and apparently the primary “glue” responsible for soil aggregation.  Iidentified by its immunoreactive properties combined with the extraction process necessary to isolate it, a common practice in soil science.


Grok |ɡräk|: verb (groks, grokking, grokked):  a word coined by American writer Robert A. Heinlein for his 1961 science fiction novel Stranger in a Strange Land. While the Oxford English Dictionary summarizes the meaning of grok as “to understand intuitively or by empathy, to establish rapport with” and “to empathize or communicate sympathetically (with); also, to experience enjoyment”,[1] Heinlein’s concept is far more nuanced, with critic Istvan Csicsery-Ronay Jr. observing that “the book’s major theme can be seen as an extended definition of the term.”[2] The concept of grok garnered significant critical scrutiny in the years after the book’s initial publication.  (Wikipedia)


Ground water (groundwater): “the water flowing by gravity, below the surface of the Earth, and which fills the pore spaces of the alluvium, soil, or rock formation” (Ponce 2007)


Hydrography(-ic): “the science of the measurement and description and mapping of the surface waters of the earth with special reference to navigation” via Google


Hyporheic zone:  zone of exchange of surface water with groundwater;  “saturated interstitial areas beneath the stream bed and [dynamically] into the stream banks that contain some proportion of [stream] channel water or that have been altered by channel water infiltration (advection)” (White 1993).  In three contexts: zoologically, “a groundwater zone penetrated by amphibiontic [see note] stream organisms”; metabolically, “a groundwater zone in which microbial mediated chemical dynamics exert controls on materials cycles in the active channel and associated riparian vegetation; hydrologically, “the hyporheic zone includes the groundwater volume that may be hydraulically interactive with the channel hydrograph over short times scales (e.g., hours)” (Stanford and Ward 1993); hyporheos: the invertebrate fauna of the hyporheic zone (Hynes 1983)  Note: Amphibiontic:  epigean organisms [literally, of or near the ground surface, thus, in a watery environment, of stream channel origin; contrast with hypogean organisms, of groundwater origin] with hyporheobiont life-history stages (Brunke and Gosner 1997)


Infiltration: the movement of water into the soil, from whence percolation ensues

Infiltration capacity: “the maximum rate at which water can enter the soil surface . . . determined by the noncapillary porosity of the soil surface after it has been thoroughly wetted, but not to the point of saturation” (Lassen et al. 1952)


Interflow: subsurface flow; “flow that takes place in the unsaturated soil layers located beneath the ground surface. Interflow consists of the lateral movement of water and moisture toward lower elevations, and it includes some of the precipitation abstracted by infiltration. It is characteristically a slow process, but eventually interflow volumes flow into streams and rivers” (Ponce 1989b)


Macropore: soil pore space large enough that the force of gravity outweighs other physical forces on water in the (noncapillary) pore; usually between soil aggregates. Compare with Micropore.


Micropore: small, capillary soil pore space where retention storage occurs.  Compare with Macropore.


Mycorrhiza(-s): [myco < Gk: fungus + rhiza <Gk: root] mutualistic soil association between fungal species and vascular plants; includes the most common, (vesicular-) arbuscular mycorrhizas [AM(F) or the older VAM] a.k.a. endomycorrhizas, wherein extensions of the fungal hyphae enter the plant root cells.  The second most common type are ectomycorhizas, wherein the relationship is strictly external, with the fungal hyphae associated with, but not entering the root cells—common among forest tree species.  Ericoid mycorrhizal fungi are associated with plant species in the Ericaceae, the heath family, that includes manzanitas, madrone and huckleberries. Other types of mycorrhizas need not be elaborated upon here.


Noncapillary (water, pore space, etc): “gravitational water” (Hursh and Fletcher 1942); noncapillary soil water exists in pore spaces large enough (macropores) that the force of gravity outweighs other physical forces.  See soil water.


Percolation: the movement of water downward through the soil, following infiltration

Percolation capacity: the rate at which water will move through soil; determined by its noncapillary porosity and thus independent of infiltration rate and soil-water storage (Lassen et al. 1952)


Phreatophyte: “rooted plant that obtains water from a permanent ground supply or from the water table, or from soil just above it” (Ponce 2007); note also: “hydrophyte = a plant adapted to live in water or waterlogged soil; hygrophyte = a plant that thrives in very wet soil and/or is more or less restricted to moist sites” (Ponce 2007)


Rational Equation/ Formula:  Simplest method to determine peak discharge from drainage basin runoff.   Rational Equation:  Q=ciA ,  where:

Q = Peak discharge, cfs
c = Rational method runoff coefficient
i = Rainfall intensity, inch/hour
A = Drainage area, acre

Various interpretations of the rational equation may be found online.  The most comprehensive treatment Verna has seen is that presented in the Oregon Department of Transportation Hydraulics Manual.  Nice work, OR DOT!


Retention: water is held against the force of gravity, above or within the soil.  Within the soil retention occurs within capillary pore spaces (micropores), where the retained water is available for uptake by plants.  Above ground retention is accomplished by dams or similar obstructions.


Riparian: adjective basically meaning streamside; “of, pertaining to, or situated or dwelling on the bank of a river or other body of water” (Webster’s Encyclopedic Unabridged Dictionary of the English Language 1989)


Self-organizing(-ed) systems: “physical and biological systems in which pattern and structure at the global level arises solely from interactions among the lower-level components of the system.  The rules specifying interactions among the system’s components are executed using only local information without reference to the global pattern.” (Camazine 2003)  So-called emergent properties and behavior are products of self-organizing systems.


Soil: “the biologically excited layer of the earth’s crust. It is an organized mixture of organic and mineral matter. Soil is created by and responsive to organisms, climate, geologic processes, and the chemistry of the aboveground atmosphere. Soil is the rooting zone for terrestrial plants and the filtration medium that influences the quality and quantity of Earth’s waters. Soil supports the nearly unexplored communities of microorganisms that decompose organic matter and recirculate many of the biosphere’s chemical elements. Ecologists consider soil to be the central processing unit of the earth’s environment (Sanchez 1994, Richter and Markewitz 1995).

Soil_compaction: “ . . . the packing together of the soil particles by a force exerted on the soil. This force is represented by any weight—that of a person, truck, or animal, or the impact of raindrops on bare soil. . . . Its principal effect, so far as soil-water relations are concerned, is reduction of soil pore space corresponding to an increase in soil density. Reduction of pore space is achieved chiefly at the expense of the noncapillary pores—those governing infiltration capacity .” (Lassen et al. 1952)


Soil water: exists in four basic forms:

1.) gravitational water, drained by macropores (see noncapillary),

2.) micropore or “capillary” water, available to plants,

3.) hygroscopic water, bound so tightly to soil particles by hygroscopic forces (absorbing water from the air) that it is not available to plants, and

4.) “water vapor, which occurs in the soil atmosphere and moves along vapor pressure gradients. It probably is not directly used by plants”  (Kramer 1949).


Terroir |terˈwär| noun: the complete natural environment in which a particular wine is produced, including factors such as the soil, topography, and climate.

  • (also goût de terroir |ɡo͞o də| )the characteristic taste and flavor imparted to a wine by the environment in which it is produced.  (Mac OS 10.11.6 Dictionary)


Transpiration: the passage of water vapor through membranes or pores, used herein to refer to its passage through the stomata of vascular plants into the atmosphere. Like evaporation, the process is partly driven by relative humidity in the vicinity of the plant; unlike evaporation, it is also strongly controlled by plant physiology, and is furthermore subject to the increased local relative humidity affected by the transpiration of neighboring plants — a feedback system.


Unsaturated hydraulic conductivity: applying Ponce’s (2007) definition of hydraulic conductivity, this refers to the velocity of flow through the vadose, or unsaturated, zone.

Unsaturated zone: (a.k.a. vadose zone) zone where the water storage capacity of the soil is unmet, thus it is the zone of soil aeration (Brooks et al. 2003) and is subject to strong biotic influences.  Boundaries may change and/or fluctuate over time.


Vadose zone: [<L vados (us): shallow equiv. to vad(um): a shoal, ford + -osus -ose] “the unsaturated zone extending between the ground surface and the water table” (Ponce 2007).  Aka the zone of aeration (Brooks et al. 2003).


Watershed: technically, the divide that separates drainage basins, but North Americans use it as a synonym for catchment/ drainage (Hynes 1983): a topographically defined unit of land whose waters flow through a common outlet to the ocean or other receiving body; In California, typically several scales or orders of subwatersheds are nested within the entire drainage of any river or estuary.