detailed support information - surface

SURFACE CHARACTERISTICS

What is the dominant material exposed to the sun?
The dominant surface that is exposed most directly to the sun’s incoming radiation has an effect on temperature in the local environment. Select the category that most closely matches the material present. If a close match does not exist, select the category with the most similar color.

Grass

Deciduous vegetation

Vegetation consisting of typically short plants with long narrow leaves, growing wild or cultivated on lawns and pasture.

Broad annual leaves from deciduous vegetation (may be shrub or forest).

Coniferous vegetation

Evergreen vegetation

Needle type leaves from coniferous vegetation (may be shrub or forest).

Broad leaves from evergreen vegetation (may be shrub or tree).

Light soil

Dark soil

Light gray or sand colored soils.

Dark brown to black soils.

Gravel

Concrete

Gravel stone (e.g., road or parking lot surface with gravel).

Gray gravel based concrete surface (e.g., sidewalk).

Asphalt

Water

Dark gray to black petroleum and gravel based surface (e.g. road or parking lot).

Open water

Not exposed

Other

Surfaces not exposed to the sun (e.g., streams in buried culverts)

If the surface does not match the choices provided a description should be included in notes.

What percent of the map unit’s ground surface is covered by fallen stems/branches that are less than 3 inches in diameter?
Estimate the percent area of the map unit that is covered by stems and branches lying on the ground.

 
  If present, what is the average density of the stems/branches?
  
  Very sparse
  (<10%) 
  Sparse (10-30%) 
  Medium (30-60%) 
 
  Less
  than 10% of underlying surface is visually obscured where stems and branches
  are present.
  10 – 30% of underlying
  surface is visually obscured.
  30 – 60% of underlying
  surface is visually obscured. 
 
  Dense (60-90%) 
  Very dense (>90%) 
  
  60
  – 90% of underlying surface is visually obscured. 
  Greater than 90% of
  underlying surface is not visible due to stem/branch coverage.

What percent of the map unit is covered by litter/duff?
Litter refers to the upper layer of loose, organic debris that is discernable plant or animal material on the ground. Decomposition may have begun, but components are still recognizable. Duff is less discernable as plant or animal material because it is broken down to very small fragments. Decomposition in the duff layer is more advanced than in the litter layer, but not yet as advanced or as incorporated in the soil as soil organics. Duff is the fermentation and humus layer of organic debris beneath the litter layer.

What percent of the map unit’s surface is exposed (not covered by living or dead vegetation)?
Estimate the percent of exposed materials such as soils, gravels, rocks, bedrock, man-made surfaces or structures, etc. that are not covered by vegetation, litter/duff, stems/branches, etc. In aquatic map units, estimate this based on the exposed bed or bottom (soil, gravels, rocks, bedrock, etc. beneath the water).

Which type of natural or man-made material is most dominant?

Organic material

Clay (<0.002” diameter)

Fine plant and animal remains that have accumulated and become integrated within the soil. This differs from litter/duff, which is not yet decayed to the point of resembling or integrating into soil.

Mineral soil particles that are less than 0.002 inches in diameter. Clays are plastic and cohesive forming ribbons when worked with some moisture.

Silt (0.002”-0.05” diameter)

Sand (0.05”-0.1” diameter)

Mineral soil particles that are between 0.002 inches and 0.05 inches in diameter. Silts are fine non-cohesive particles.

Sediment particles, often largely composed of quartz, generally classified as fine, medium, coarse or very coarse. Beach sand may sometimes be composed of organic sediments such as reef debris or shell fragments.

Gravel (0.1”-4” diameter)

Cobble (4”-10” diameter)

Unconsolidated natural accumulation of rock fragments coarser than sand but finer than cobble.

Stone/rock that has been made smooth by the abrasive action of flowing water or waves.

Rocks (10”-24” diameter)

Boulders (≥24” diameter)

An aggregate of one or more minerals, or a body of undifferentiated mineral matter.

Mass of rock that is at least 24 inches in diameter.

Bedrock

Man-made pervious/porous surface

A general term for the rock, usually solid, that underlies soil or other unconsolidated, superficial material.

Permeable, human-made or engineered substances/surfaces, or human imported substances that were not part of the initial natural environment, such as gravel, bark dust, riprap, etc., and which covers the soil/substrate.

Man-made impervious

Unknown/Other

Human-made or engineered substances/surfaces within the map unit that do not allow water passage into or through the substance, such as concrete, etc.

Substrate material that cannot be identified or seen (e.g. due to poor visibility, lack of access to map unit, etc.), or does not meet definitions of other substrates (e.g. coal ash, wood ash, etc.).

How much does each of the following contribute to the composition of the exposed surface?
Evaluate already exposed areas where present. If debris or other material makes it difficult to see the exposed area, move the material so that the area can be evaluated. Several types of material may be present, the combination of materials should equate to about 100%.

TOPOGRAPHY

What percent of the map unit contains microtopography?
Microtopography is the variability of surface height, generally between 1-6 inches. It is used to evaluate movement of water across a surface. Ridges, mounds and other small-scale variations affect the amount of time water takes to move across a surface.

What percent of the map unit’s area is made up of depressional areas (areas greater than 6 inches in depth relative to the surrounding surface)?
This is a visual estimate of the depressional areas that could hold ponded water. For example, if the whole map unit is a depressional area, then select >90%. If there are a series of small depressional areas within a larger map unit, estimate the percent of the map unit all the depressional areas combined would occupy. If water is not currently ponded, use visual clues to ascertain general ponding conditions during wet periods (from rain events, snow melt, flooding from a nearby water body, irrigation, and/or by overland flow).

What is the slope (gradient) of the map unit? Select the predominant slope where multiple slopes are present.
This is a measure of the gradient of the ground or water surface and it is expressed as the percent change in elevation over the length of the map unit. Use visual estimation or estimate using a clinometer.

If “<3%” or “1 - 2°” is selected and the map unit has flowing water (i.e., stream or river) then select a specific granularity.
Some of ESII’s models require more granular data when flowing water is present because of associated exponential changes in velocity and because of flowing water’s ability to move particles.

If there is a predominant slope, what is the longest length of the map unit along the fall-line?
The fall-line is the path water would take as it moves down slope, perpendicular to the contour lines. For map units with multiple fall-lines (e.g., high points within the map unit) estimate the length along the longest cumulative path.

PERMEABILITY

How permeable is the soil?
This is an estimate, based on visual evidence or knowledge of the site, of the ability of water to move through the upper layers of soil (it is understood that materials evaluated at the surface may not necessarily reflect the underlying hydrology).

Soil has HIGH permeability (e.g. majority sand and gravel): Low runoff potential when thoroughly wet. Water is transmitted freely through the soil, which typically has less than 10% clay and more than 90% sand or gravel and has gravel or sand texture. Some soils having loamy sand, sandy loam, loam, or silt loam textures may be in this group if they are well aggregated, of low bulk density, or contain greater than 35% rock fragments.
Soil has MODERATE permeability (e.g. mostly sand with some clay or silt): Moderately low runoff potential when thoroughly wet. Water transmission through the soil is unimpeded. Soil typically has between 10% and 20% clay and 50% to 90% sand and has loamy sand or sandy loam texture. Some soils having loam, silt loam, silt, or sandy clay loam textures may be in this group if they are well aggregated, of low bulk density, or contain greater than 35% rock fragments.
LOW (e.g. mostly clay or silt with some sand): Moderately high runoff potential or ponding when thoroughly wet. Water transmission through the soil is somewhat restricted. Soil typically has between 20% and 40% clay and less than 50% sand and has loam, silt loam, sandy clay loam, clay loam, and silty clay loam texture. Some soils having clay, silty clay, or sandy clay textures may be in this group if they are well aggregated, of low bulk density, or contain greater than 35% rock fragments.
VERY LOW e.g. mostly clay): High runoff potential or ponding when thoroughly wet. Water movement through the soil is restricted or very restricted. Soil typically has greater than 40% clay, less than 50% sand, and has clay-like texture. In some areas, the soil also has high shrink-swell potential.
NONE of the above: Soil surface is covered by man-made surface, soil cannot be assessed, or water cannot reach soil surface.

WATER REGIME

Does the map unit become saturated or inundated over the course of a normal year?

No: No signs of inundation.
Saturated: Some evidence of frequent wetting or water at the surface due to proximity to groundwater, but standing water is not prevalent (may be based on site observations or knowledge of the site). Soil pore spaces are filled with water. Evidence includes muddy soils during normally dry periods or locations where the soil surface is wet for extended periods.
Inundated: Water is present at or above the soil surface from accumulation of precipitation and/or flooding from adjacent areas. Evidence of persistent inundation includes water lines on trees trunk, debris accumulations, etc.

If the map unit is saturated or inundated during the course of a normal year, is the saturation or inundation occasional, seasonal, or permanent?

Occasional: Surface water and/or soil saturation may occur at certain times but not every year.
Seasonal: Surface water and/or soil saturation is present every year during a particular season.
Permanent: Surface water and/or soil saturation is present throughout the year.

If the map unit is saturated or inundated during the course of a normal year, what percent of the map unit is affected by saturation or inundation (this may be based on local knowledge of the site)?
Estimate the percent of the map unit that contains, or shows evidence of, standing water or saturated soils.

If the map unit is saturated or inundated during the course of a normal year, what is the salinity regime?
This measure is based on site context and knowledge, not water sampling.

Fresh water: Salt concentrations less than 0.05%; typical of natural lakes, ponds, or streams.
Brackish water: Salt concentrations between 0.05% and 3%; typical of estuarine rivers or some man-made special purpose reservoirs.
Sea water: Salt concentrations between 3% and 5%; typical of marine conditions or some man-made special purpose reservoirs.
Brine: Salt concentrations that are greater than 5%; typical of natural water bodies in arid climates with high rates of evaporation or some man-made special purpose reservoirs.
Other: Other dissolved solutes at concentrations that do not appropriately match up to the conditions above. Examples may include structures such as sediment cooling ponds or stormwater contaminated by road salt.

If the map unit is saturated or inundated during the course of a normal year, what type of water motion is present?

Still: Water has no movement or is very slow (e.g., pond, reservoir, etc.)
Flowing: Water in motion (e.g., stream, river, etc.)

What is the average bankfull width for the map unit?
Measure or estimate the average horizontal distance between the points where the water level of a stream, river or lake is at the top of its banks and any further rise would result in water moving into the flood plain. Bankfull is distinguished from Ordinary High Water (OHW) because OHW may exceed the confinement of the banks during average annual high flow events. In severely entrenched systems, OHW may be less than the bankfull width. The U.S. Army Corps of Engineers defines OHW as “that line on the shore established by the fluctuations of water and indicated by physical characteristics such as a clear, natural line impressed on the bank, shelving, changes in the character of soil, destruction of terrestrial vegetation, the presence of litter and debris, or other appropriate means that consider the characteristics of the surrounding areas.”

What is the average bankfull height for the map unit?
Measure or estimate the vertical distance from the streambed to the point where any further rise would result in water moving into the flood plain.

What is the average Ordinary High Water (OHW) width for the map unit?
This is the distance between the tops of the OHW elevations on each side of the stream. The Army Corps of Engineers defines OHW as “that line on the shore established by the fluctuations of water and indicated by physical characteristics such as a clear, natural line impressed on the bank, shelving, changes in the character of soil, destruction of terrestrial vegetation, the presence of litter and debris, or other appropriate means that consider the characteristics of the surrounding areas.”

What is the average height to Ordinary High Water (OHW) for the map unit?
This is the average vertical distance from the streambed to the height at level of OHW within the map unit.

Is the map unit within a low, medium, or high sinuosity (degree of curve or bend) system?
Sinuosity characterizes a river’s tendency to move back and forth across the floodplain, in an S-shaped pattern, over time. This question should be answered in the context of the system in which the map unit is located. Map Unit (MU) #001 in the examples below has low sinuosity when evaluated by itself, but when evaluated in aggregate with other map units, it may be part of more sinuous systems.

What is your level of certainty for the stream dimension measurements?

Low: Heights and widths are estimated visually.
Medium: Heights and widths are estimated with fixed length device (e.g., yard stick).
High: Heights and widths measured with graduated instrument (e.g., measuring tape).

What percent of the map unit contains open water that is free of vegetation or other obstructions?
Open water does not have emergent vegetation, artificial obstructions, or masses of underwater vegetation in shallow areas.

When water is present, what is the predominant depth?
If the average depth is not easily estimated due to water body size, lack of visual clarity or limited access, make an estimated guess of the depth to the extent possible given access and safety considerations. Use local knowledge where available.

What area of the map unit is made up of, or affected by, a seep or spring?
A seep or spring is a discrete location within a terrestrial map unit where cool groundwater discharges on the ground.

Are surface sheens (iridescent or rainbow-like films) present?
The questions regarding surface sheens are collected for the user’s information only.

If “Yes,” are the surface sheens natural (from bacteria) or unknown?
There are multiple sources of water surface sheens, some natural and some man-made. If there is no obvious source, the sheen may be an organic sheen caused by natural bacteria. Sheens caused by bacteria can be broken using a stick or stone, resulting in pieces with distinct edges that do not rejoin cleanly with other pieces. If the sheen breaks in this manner then record as “Natural”.

NEIGHBORING MAP UNITS

Is the map unit adjacent to a developed area (industrial plant, road, ag. field, etc.)?
This may include another map unit or areas off-site.

Is the map unit adjacent to areas of permanent open water?
This question refers to adjacency to permanent open water features, such as rivers, ponds, lakes, etc. Such features do not have to be within the project boundary, as long as they are adjacent to the map unit.

If “Yes,” what direction is the center of the map unit from the adjacent open water area? Select all that apply.
If the water body wraps around the map unit, or the map unit wraps around the water body, there may be more than one direction applicable. Check all that apply.

DISTURBANCES

What percent of the map unit shows evidence of any type of recent man-made VEGETATION disturbance?
Disturbance can result from more than one cause, including clearing, mowing, cattle grazing, compaction of shrubs and herbaceous vegetation, evidence of fire or flooding, etc. It does not include areas where vegetation can no longer grow, such as paved parking lots, buildings, concrete stormwater channels, etc. The map unit must contain visual evidence of disturbance at the time of data collection.

What percent of the map unit shows evidence of man-made SOIL disturbance?
Disturbance can result from more than one cause, including soils visibly upturned, compacted, or otherwise different from an undisturbed state due to leveling, re-contouring, tillage, excavation, placement of fill, or compaction (i.e., a dirt road). It does not include soils that have been covered by man-made structures, roadways, managed material piles and mounds (gravel, bark dust, etc.), or aquatic substrates. The map unit must contain visual evidence of disturbance at the time of data collection.

Of the disturbed area, what percent of the soil disturbance is due to compaction (from vehicle traffic, construction, agriculture, etc.)?

Of the disturbed area, what percent of the soil disturbance is due to conventional tillage practices or comprised of over-turned (bladed) soil?