Definitions Flashcards
Accuracy
The closeness of observations, computations, or estimates to the true values or to values accepted as being true
Aerial
Of, pertaining to, or occurring in the air or atmosphere
Aerial Photograph, Oblique
An aerial photograph taken with a camera axis directed between the horizontal and the vertical.
(1) high oblique - an oblique photograph in which the horizon is shown
(2) low oblique - an oblique photograph in which the horizon is not shown
Aerial Photograph, Vertical
An aerial photograph made with the optical axis of the camera approximately perpendicular to the earth’s surface and with the film as nearly horizontal as is practical
Algorithm
A statement of the steps to be followed in the solution of a problem; an algorithm may be in the form of a word description, an explanatory note, or a labeled diagram or flowchart
Alluvium
Any material deposited by running water; the soil material of floodplains and alluvial fans
Altitude
Elevation above or below a reference datum; the datum is usually the mean sea level
Analog
A form of data display in which values are shown in graphic form, such as curves
Aquifer
Any subsurface material that holds a relatively large quantity of groundwater and is able to transmit that water readily
Area
A generic term for a bounded, continuous, two-dimensional object that may or may not include its boundary
Aspect
The horizontal direction in which a slope faces, commonly expressed as compass direction (for example, North, Northeast); degrees clockwise from the North
Attribute
A defined characteristic of an entity (for example, topographic slope)
Attribute Value
A specific quality or quantity assigned to an attribute (for example, 15 percent slope)
Band
A specific frequency or range of frequencies in the electromagnetic spectrum
Baseflow
The portion of streamflow contributed by groundwater; it is a steady flow that is slow to change even during rainless periods
Berm
A low, linear mound of earth and soil
Buffer
(1) The zone around the perimeter of a wetland or lake where land-use activities are limited to protect the water features;
(2) a zone of a specified distance around any map feature in a GIS layer
Cadastre
a parcel-based land information system
Carrying Capacity
The level of development density or use that an environment is able to support without suffering undesirable or irreversible degradation
Characterization
The delineation or representation of the essential features or qualities existing at a site
Chloropleth Map
a map comprised of areas of any size or shape representing qualitative phenomena (for example, soil fertility) or quantitative phenomena (for example, elevation); often has a mosaic appearance
Climate
The general or representative conditions of the atmosphere at a place on earth
Clustering
A land development concept in which buildings and infrastructures are grouped together, and large contiguous areas of open space remain undeveloped
Coefficient of Runoff
A number given to a type of ground surface representing the proportion of rainfall converted to overland or surface flow
Color-Infrared Film
Photographic film sensitive to energy in the visible and near-infrared wavelengths of the electromagnetic spectrum (usually from 0.4 to 0.9 mm)
Concentration Time
The time taken for a drop of rain falling on the perimeter of a drainage basin to pass through the basin to the outlet
Constraint
Any feature or condition of the built or natural environment that poses an obstacle to proposed land uses
Contour
An imaginary line on the ground, all points of which are at the same elevation above or below a specific datum
Contour Interval
The difference in elevation between two adjacent contours
Control Point
Any station in a horizontal or vertical control system that is identified on a photograph and used for correlating the data shown on the photograph
Coordinate System
A reference system for uniquely defining the location of any point on earth
Crown Diameter, Visible
The apparent diameter of a tree crown imaged on a vertical aerial photograph
Data Set
A file or files that contain related geometric and attribute information; a collection of related data
Datum
A reference system for measuring another attribute, such as horizontal or vertical location
Decibel
A unit of measurement for the loudness of sound based on the pressure produced in air by a noise; denoted as dB
DEM (Digital Elevation Model)
A topographic surface arranged in a data file as a set of regularly spaced x, y, z coordinates, in which z represents elevation
Design Storm
A rainstorm of a given intensity and frequency of recurrence that is used as the basis for stormwater management
Detention
A strategy used in stormwater management in which runoff is detained on-site to be released later at some prescribed rate
Development Density
A measure of intensity of development or land use; defined, for example, on the basis of area covered by dwelling units, impervious surfaces, or building floor area
Digitization
The process of converting a photograph, map, or other image into numerical format
Discharge
The rate of water flow in a stream channel or from a site; measured as the volume of water passing through a cross-section of a stream or swale per unit of time, commonly expressed as cubic feet (or meters) per second
Discharge Zone
An area where groundwater seepage and springs are concentrated
Disturbance
An impact on the environment, such as forest clearing, characterized by physical or biological change
DLG (Digital Line Graph)
A digital representation of cartographic information; digital vectors converted from maps and related sources
DOQ (Digital Orthophotoquadrangle)
A digital image with the properties of an orthographic projection; derived from a digitized vertical aerial photograph so that image displacement caused by camera tilt and relief of terrain are removed, or rectified. Orthophotos combine the image characteristics of a photograph with the geometric qualities of a map
Drainage Network
A system of stream channels usually connected in a hierarchical fashion
Drainage Basin
The area that contributes runoff to a stream, river, of lake
Easement
A right-of-way granted, but not dedicated, for limited use of private land for a public or quasi-public purpose
Ecosystem
A group of organisms linked together by a flow of energy; it is also a community of organisms and their environment
Ecotone
The transition zone between two groups, or zones, of vegetation
Electromagnetic Radiation (EMR)
Energy propagated through space in the form of an advancing interaction between electric and magnetic fields. EMR is also called electromagnetic energy.
Elevation
Vertical distance from a datum point, such as mean sea level, to a point or object on the earth’s surface; not to be confused with altitude, which refers to points or objects above the earth’s surface
Endangered Species
According to the U.S. Endangered Species Act, a species of imminent danger of extinction in all or a significant portion of its range
Environment
The aggregate conditions that affect the existence or development of properties intrinsic to a site
Environmental Site Characterization
The delineation or representation of the essential features or qualities, including all of the conditions, influences, and circumstance, existing at a place or location designated for a specific use, function, or study
Environmental Assessment
A preliminary study or review of a proposed action (project) and the influence it could have on the environment; often conducted to determine the need for more detailed environmental impact analysis
Ephemeral Stream
A stream without base flow; one that flows only during or after rainstorms or snowmelt events
Erosion
The removal of rock debris by moving water, wind, or another agent; generally, the sculpting or wearing down of the land by erosional agents
Eutrophication
The increase of biomass of a water body leading to infilling of the basin and the eventual disappearance of open water
Evapotranspiration
The loss of water from the soil through evaporation and transpiration
Feasibility Study
A type of planning aimed at identifying the most appropriate use of a site
Filtration
A term generally applied to the removal of pollutants, such as sediment, with the passage of water through a soil, organic, and/or fabric medium
Floodway Fringe
The zone designated by U.S. federal flood policy as the area in a river valley that would be lightly inundated by the hundred-year flood
Floor Area
The area of all floors of a building or structure
Footprint
Area covered by a building
Geocoding
A coding process in which a digital map feature is assigned an attribute value (for example, vertical or horizontal location)
Geographic Information System (GIS)
A mapping system designed for analysis, planning, and management applications involving overlapping and complex distributional patterns. Two classes of GIS are vector and raster.
Geomorphology
A science that deals with the land and submarine relief features of the earth’s surface, or the comparable features of a celestial body, and seeks a genetic interpretation of them.
Georeference
To establish the relationship between coordinates on a planar map and real-world coordinates
Geospatial Data
Information identifying the geographic location and characteristics of natural or constructed features and boundaries on the earth; geospatial data may be derived from, among other things, remote sensing, mapping, and surveying technologies
Geostationary Satellite
A satellite placed in orbit above the earth; it rotates with the earth and, thus, remains fixed over the same area.
Global Positioning System (GPS)
The Navigation Satellite Timing and Ranging (NAVSTAR) GPS is a passive, satellite-based, navigation system operated and maintained by the Department of Defense (DOD)
Global Coordinate System
The network of east-west and north-south lines (parallels and meridians) used to measure locations on earth; this system uses degrees, minutes, and seconds as the units of measurement
Gradient
The inclination or slope of the land, often applied to systems such as streams and highways
Ground Truth (jargon)
The term coined for data and information obtained on surface or subsurface features to aid in interpretation of remotely sensed data; ground data and ground information are the preferred terms.
Ground Resolution
The area on the terrain that is covered by the instantaneous field of view of a detector; ground resolution is determined by the altitude of the remote-sensing system and the instantaneous field of view of the detector
Ground Data
Data collected on the ground, and information derived there from, as an aid to the interpretation of remotely recorded surveys, such as airborne imagery; generally, this should be performed concurrently with the airborne surveys; data collected on weather, soils, and vegetation types and conditions are typical
Groundwater
The mass of water that occupies the subsoil and upper bedrock zone; the water occupying the zone of saturation below the soil-water zone
Habitat
The local environment from which an organism gains its resources; habitat is often variable in size, content, and location, changing with the phases in an organism’s life cycle
Hardpan
A hardened soil layer characterized by the accumulation of colloids and ions
Hazard Assessment
An evaluation of the dangers to land use and people from environmental threats such as floods, tornadoes, and earthquakes
Horizon
A layer in the soil that originates from the differentiation of particles and chemicals due to moisture movement within the soil column
Hydric Soil
Soil characterized by wet conditions, or saturation, most of the year - often organic in composition
Hydrograph
A streamflow graph that shows the change in discharge over time, usually hours or days
Hydrologic Cycle
The planet’s water system, described by the movement of water from the oceans to the atmosphere to the continents and back to the sea
Impervious Cover
Any hard surface material, such as asphalt or concrete, that limits stormwater infiltration and induces high runoff rate
Infiltration Capacity
The rate at which a ground material takes in water through the surface; measured in inches or centimeters per minute or hour
Infrared Image
An image acquired within the wavelength from about 0.7 mm to about 2.6 mm; thermal infrared is between 2.6 mm and 13.5 mm
Infrared Film
Photographic film capable of recording near-infrared radiation (just beyond the visible to a wavelength of 0.9 micrometer), but not capable of recording thermal infrared wavelengths
Infrared Radiation
Mainly long wave radiation of wavelengths between 3.0-4.0 and 100 micrometers; it includes near-infrared radiation, which occurs at wavelengths between 0.7 and 3.0-4.0 micrometers
Isopleth Map
A map comprised of lines (isolines) that connect points of equal attribute value
Lacustrine Wetland
A wetland associated with standing water bodies such as ponds, lakes, and reservoirs
Land Cover
The materials such as vegetation and concrete that cover the ground. See also Land Use.
Land Use
The human activities occurring within an area of the landscape; for example, agricultural, industrial, and residential uses
Layer
In a geographic information system, spatial data of a common type or theme
Legend
An explanation of the symbols, colors, and styles used on a map or plan, usually in a box next to the map or plan
Lithosphere
The solid part of the earth or other spatial body, distinguished from the atmosphere and the hydrosphere
Lot
A parcel, tract, or area of land established by a plat or otherwise as permitted by law
Lot Frontage
The portion of a lot adjacent to a street
Magnetic Declination
The deviation in degrees east or west between magnetic north and true north
Map
A graphical representation of a portion of the earth’s surface, drawn to scale, on a specific projection, showing natural and manmade features
Map Projection
An orderly system of lines on a plane representing a corresponding system of imaginary lines on a datum surface
Metadata
“Data about data” describe the content, quality, condition, and other characteristics of data; for example, the date and source from which field data were collected
Monochromatic
Pertaining to a single wavelength or, more commonly, to a narrow band of wavelengths
Microclimate
The climate of small spaces, such as inner city, a residential area, or a mountain valley
Mitigation
A measure used to lessen the impact of an action on the natural or human environment
Mitigation Banking
In wetland mitigation planning, the practice of building surplus acreage of compensation credits through replacement, enhancement, restoration, and/or preservation of wetlands
Moraine
The material deposited directly by a glacier; the material (load) is also carried in or on a glacier; as landforms, moraines usually have either hilly or rolling topography
Mosaic
A term used in landscape ecology to describe the patchy character of habitat as a result of fragmentation through land use; an assemblage of overlapping aerial or space photographs or images whose edges have been matched to form a continuous pictorial representation of a portion of the earth’s surface
Nonpoint Source
Water pollution from a spatially diffuse source such as the atmosphere or agricultural land
Palustrine Wetland
Wetlands associated with inland sites that are not dependent on streams, lakes, or oceanic water
Panchromatic
A term used for films that are sensitive to broadband (that is, the entire visible part of the electromagnetic spectrum)
Parent Material
The particulate material in which a soil forms; the two types of parent material are residual and transported
Peak Discharge
The maximum flow of a stream or a river in response to an event such as a rainstorm, or over a period of time such as a year
Percolation Rate
The rate at which water moves into soil through the walls of a test pit; used to determine soil suitability for wastewater disposal and treatment
Percolation Test
A soil-permeability test performed in the field to determine the suitability of a material for wastewater disposal and treatment
Permeability
The rate at which soil or rock transmits groundwater (or gravity water in the area above the water table)
Photogrammetry
The art or science of obtaining reliable measurements by means of photography
Photosynthesis
The process by which green plants synthesize water and carbon dioxide and, with the energy from absorbed light, convert it into plant materials in the form of sugar and carbohydrates
Physiography
A term from physical geography that is traditionally used to describe the composite character of the landscape over large regions
Planned Unit Development (PUD)
An area planned, developed, operated, and maintained as a single entity containing one or more structures and common areas; it may include multiple land uses (for example, commercial or residential)
Plat
A map or maps of a subdivision or site plan
Point Source
Water pollution that emanates from a single source such as a sewage plant or stormwater outfall
Radiation
The process by which radiant (electromagnetic) energy is transmitted through free space; the term used to describe electromagnetic energy, as in infrared radiation or short-wave radiation
Rainfall Intensity
The rate of rainfall measured in inches or centimeters of water deposited on the surface per hour or minute
Rational Method
A method of computing the discharge from a small drainage basin in response to a given rainstorm; computation is based on the coefficient runoff, rainfall intensity, and basin area
Recharge Zone
An area where groundwater recharge is conentrated
Recharge
The replenishment of groundwater with water from the surface
Relief
The range of topographic elevation within a prescribed area
Retention
A strategy used for stormwater management in which runoff is retained on-site in basins, underground, or released into the soil
Right-of-Way
A strip of land occupied or intended to be occupied by a street, one or more walkways, utility lines, or other special uses
Riparian Wetland
Wetlands that form on the edge of a water feature such as a lake or stream
Riparian
The environment along the banks of a stream, often more broadly applied to the larger lowland corridor on the stream valley floor
Risk Management
An area of planning that involves preparation and response to hazards such as floods, hurricanes, and toxic waste accidents
Rubber Sheet
A procedure to adjust features of a digital GIS layer in a nonuniform manner; representing “from” and “to” locations are used to define the adjustment
Runoff
The flow of water from the land as both surface and subsurface discharge; in the more restricted and common use, surface discharge is in the form of overland flow and channel flow
Scale
The relationship between a distance on a map, chart, or photograph and the corresponding distance on the earth
Septic System
A sewage system that relies on a septic tank to store and/or treat wastewater; generally, an on-site (small-scale) sewage disposal system that depends on the soil for wastewater treatment
Setback
The minimum distance that a structure or facility should be separated from an edge, such as a property line.
Siltation
The deposition of sediment in water due to soil erosion and stormwater runoff.
Soil Profile
The sequence of horizons, or layers, of a soil.
Solar Heating
The process of generating heat from absorbed solar radiation.
Solar Gain
The amount of solar radiation absorbed by a surface or setting in the landscape.
Solstice
The dates when the declination of the sun is at 23.27 degree north latitude (the Tropic of Cancer) and 23.27 degrees south latitude (Tropic of Capricorn) - June 21-22 and December 21-22, respectively.
Spatial Data
Data or information with implicit or explicit information about location.
Stream Order
The relative position, or rank, of a stream in a drainage network. Streams without tributaries, usually the small ones, are first order; streams with two or more first-order tributaries are second order, and so on.
Subdivision
The division of a lot, tract, or parcel of land into two or more lots, tracts, or parcels for sale or development.
Sun Angle
The angle formed between the beam of incoming solar radiation and a plane at the earth’s surface.
Surge
A large and often destructive wave caused by intensive atmospheric pressure and strong winds.
Threatened Species
According to the U.S. Endangered Species Act, a species with a rapidly declining population that is likely to become endangered.
TIN
Triangulated irregular network. A surface representation derived from irregularly spaced points and breakline features. Each sample point has an x, y coordinate and a z (surface) value.
Topsoil
The uppermost layer of the soil, characterized by a high organic content.
Water Table
The upper boundary of the zone of groundwater. In fine-textured materials it is usually a transition zone rather than a boundary line. The configuration of the water table often approximates that of the overlying terrain.
Wellhead Protection
Land-use planning and management to control contaminant sources in the area contributing recharge water to community wells.
Wetland
An area where the ground is permanently wet or wet most of the year and is occupied by water-loving (or tolerant) vegetation, such as cattails, mangrove, or cypress.
Zenith
For any location on earth, the point that is directly overhead to an observer.
Adaptation
A genetically determined characteristic that enhances the ability of an organism to better adjust to its surroundings.
Adiabatic Lapse Rate
A variation in temperature of a parcel of air up or down a change in elevation. This does not take into account exchanges of heat between the air parcel and the environment.
Administration
Execution of an organizational policy to reach predetermined objectives.
Advection
The transfer of an atmospheric property due to mass air motion along a gradient of the property in question; the horizontal spreading of local effects by wind.
Agricultural District
A legally recognized geographic area formed by one or more landowners and approved by one or more government agencies, designed to keep land in agriculture. Agricultural districts are created for fixed, renewable terms. Enrollment is voluntary; landowners receive a variety of benefits that may include eligibility for differential assessment, limits on annexation and eminent domain, protection against unreasonable government regulation and private nuisance lawsuits, and eligibility for purchase of agricultural conservation easement programs. Agricultural districts are also known as agricultural preserves, agricultural security areas, agricultural preservation districts, agricultural areas, agricultural incentive areas, agricultural development areas, and agricultural protection areas
Agricultural lands
Places used for crop or animal production or for silviculture.
Agricultural Zoning
A zoning ordinance or zoning district design to protect farmland from incompatible nonfarm uses. There are several types of agricultural zoning, which vary according to (1) the uses allowed in the zone (i.e., exclusive or nonexclusive farm use); (2) the minimum farm size allowed, such as a 50-acre (20.2-hectare) minimum lot size; (3) the number of nonfarm dwellings allowed, such as one building lot per 25 acres (10.1 hectares); and (4) the size of setbacks or buffer areas between farms and nonfarm properties
Air Mass
A widespread body of air that gains certain characteristics while set in one location. The characteristics change as it moves away.
Air Parcel
A space of air over a certain area of land.
Air Pollution Areas
Places that require restraints on air pollution emissions due to periods of poor vertical air mixing and the subsequent entrapment of polluting substances.
Albedo
Reflected solar radiation factor.
Alluvium
The soil material deposited by running wtaer.
Analysis
The examination of individual parts to find out their nature, function, and interrelationship with other parts.
Abiotic
Those aspects dealing with nonliving matter
Annexation
The incorporation of land into an existing community that results in a change in the community’s boundary. Annexation generally refers to the inclusion of newly incorporated land but can also involve the transfer of land from one municipality to another.
Aquifer
A water-bearing layer of permeable rock, sand, or gravel
Aspect
Orientation toward some direction
Basalt
A hard, fine-grained igneous rock caused by volcanism
Base Map
A reproducible map used to display various types of information.
Biodiversity (biological diversity)
The variety and abundance of all life-forms considered at all levels of organization, from the genetic level through the species and higher levels of taxonomic organization, and including the variety of habitats, communities, landscapes, and ecosystems.
Biogeochemical cycles
Mineral and nutrient cycles that are important to the biological community
Biological
Those aspects dealing with living matter
Biosphere
The portion of earth and its atmosphere that can support life
Biota
All living organisms that exist in an area
Biotic Community
An assemblage of plants and animals living in the same community, forming a system that is mutually sustaining and interdependent and influenced by the abiotic factors of the ecosystem. A biotic community is generally characterized by the dominant vegetation.
Board of Adjustment
An independent board created to handle conditional uses, variances, and special applications of regulations established by a zoning ordinance and to hear and act on appeals.
Building Code
The legal requirements pertaining to the building of structures.
Canopy Layer
The uppermost layer of forest vegetation.
Capability
An evaluation based on a resource’s inherent, natural, or intrinsic ability to provide for use and includes that existing ability that is the result of past alterations or current management practices. Often capability is used interchangeably with suitability.
Capability Class
An evaluation made by the U.S. Natural Resources Conservation Service concerning the agricultural management of a soil type.
Capital Improvement Programming (CIP)
The multiyear scheduling of public physical improvements. The scheduling is based on studies of fiscal resources available and the choice of specific improvements to be constructed for a period of five or six years in the future.
Carnivores
Organisms that feed on animal issue.
Carrying Capacity
(1) In ecology, the number of individuals that the resources of a habitat can support.
(2) In wildlife, the maximum number of animals an area can support during a given period of the year.
(3) In recreation, the amount of use a recreation area can sustain without deterioration of its quality.
Circuit Breaker Tax Relief
A tax abatement program that permits eligible landowners to take some or all of the property tax they pay on farmland and farm buildings as a credit to offset their state income tax. Generally, farmers are eligible for a credit when property taxes exceed a set percentage of their income.
Citizen Participation
The involvement of the public in the planning process
Citizens’ Advisory Committee (CAC)
A group of citizens called together by an agency to represent the ideas and attitudes of their community in advising and giving consultation to the agency.
Clay
Soil particles smaller than 0.0002 millimeters in diameter.
Climate
The set of meteorological conditions characteristic of an area over a given length of time.
Cluster Development
Grouping houses on part of a property while maintaining a large amount of open space on the remaining land. Cluster development should be seen as an open-space protection tool rather than a farmland protection tool.
Cognitive Mapping
A process by which people acquire, code, store, recall, and decode information about the relative locations and attributes of phenomena in the everyday spatial environment.
Cohort-Survival Method
A popular method for making population projections based on fertility, mortality, and net migration.
Community
(1) In sociology, a variety of physical and social areas and institutions within which and with which people live.
(2) In ecology, an association of interacting populations, usually determined by their interactions by spatial occurrence.
Compensating Wind
Wind originating above plains and flowing toward nearby mountains along a pressure gradient.
Competition
The use or defense of a resource by one individual that reduces the availability of that resource to other individuals.
Comprehensive Plan
A document setting forth official governmental policy for the long-term future development of an area that considers all major determinants of growth and change - economic, political, social, and biophysical.
Comprehensive Planning
A process for coordinating and establishing the policies set forth in a comprehensive plan.
Conditional Use
A permitted use allowed in zoning ordinances that requires review by a board of adjustment or similar review agency.
Conifer
A cone-bearing plant whose needles remain on the tree all year.
Conservation
The management of human use of the biosphere to yield the greatest sustainable benefit to present generations while maintaining its potential to meet the needs and aspirations of future generations.
Conservation Easement
A nonpossessory interest of a holder in real property imposing limitations or affirmative obligations the purposes of which include retaining or protecting natural, scenic, or open-space values of real property, assuring its availability for agricultural, forest, recreational, or open-pace use, protecting natural resources, maintaining or enhancing air or water quality, or preserving the historical, architectural, archaeological, or cultural aspects of real property. Most are permanent; term easements impose restrictions for a limited number of years.
Corn Suitability Rating (CSR)
A numerical system for rating the productivity of farmland, used primarily in Iowa.
Critical Areas
Places significantly affected by, or having an effect on, an existing or proposed major facility or other areas of major public investment; or containing or having a significant impact on historical, natural, or environmental resources of regional or statewide importance.
Cropland
Land regularly used for production of crops, except forestland and rangeland, including permanent pasture.
Cross Section
A graphic tool that illustrates a vertical section of land.
Cumulative Impact Assessment
A comprehensive planning process whereby the rate or total amount of development is managed to stay below prestated threshold levels and is halted when such thresholds are reached.
Deadwater
Unflowing stream or river water.
Decomposers
Organisms responsible for breaking down matter.
Deferred Taxation
A form of differential assessment that permits eligible land to be assessed at its value for agriculture. Taxes are based on how much money the land could produce in crops or livestock, instead of its speculative value for development. Deferred taxation is similar to preferential assessment, but landowners must pay some or all of the taxes that were excused if they later convert land to ineligible uses. Rollback taxes assess the difference between taxes paid under differential assessment and taxes that would have been due if the land was assessed at fair market value.
Delphi
A method for systematically developing an expressing the views of a panel of experts.
Design Guidelines
Local ordinances that establish standards for architecture and landscape architecture features of new development.
Detritus
Freshly dead or partially decomposed organic matter.
Detritus-Feeding Animals
Animals that ingest and break down fragments of organic matter.
Detrivores
Animals that obtain energy from decaying plant and animal matter.
Development
The modification of the biosphere and the application of human, financial, living, and nonliving resources to satisfy human needs and improve the quality of human life.
Development Rights
Development rights entitle property owners to develop land in accordance with local land-use regulations. These rights may be sold to public agencies or qualified nonprofit organization. Sale of development rights to a government agency or land trust generally does not pass any affirmative interest in the property. Rather than the right to develop the land, the buyer acquires the responsibility to enforce the negative covenants or restrictions stipulated in the development rights agreement.
Differential Assessment
An agricultural property tax relief program that allows eligible farmland to be assessed at its value for agriculture rather than its fair market value, which reflects “highest and best” use. The tax takes three different forms: preferential assessment, deferred taxation, and restrictive agreements. This approach is also known as current-use assessment, current-use valuation, farm-use valuation, and use assessment.
Dike
Hardened lava extending in a direction other than that of the flow. Also, earthen elevated barrier erected to prevent land from uncontrolled flooding.
Dominant Species
A species that has a controlling influence on the local environment.
Downzoning
A change in the zoning for a particular area that results in lower residential densities. For example, a change from a zoning ordinance that requires 10 acres (4.05 hectares) per dwelling to an ordinance that requires 40 acres (16.2 hectares) per dwelling is a downzoning.
Drainage Basin
A part of the earth’s surface that is occupied by a drainage system, which consists of a surface stream or a body of impounded surface water together with all tributary surface streams and bodies of impounded surface water.
Drainage Class
The relative terms used to describe natural drainage as follows:
Excessive: Commonly very porous and rapidly permeable soils that have low water-holding capacity.
Somewhat Excessive: Very permeable soils that are free from mottling throughout their profile.
Good: Well-drained soils that are nearly free of mottling and are commonly of intermediate texture.
Moderately Good: Moderately well-drained soils that commonly have a slow permeable layer in or immediately beneath the solum. They have uniform color in the surface layers and upper subsoil and mottling in the lower subsoils and substrata.
Somewhat Poor: Soils wet for significant periods but not all the time. They commonly have a slowly permeable layer in the profile, a high water table, additions through seepage, or a combination of these conditions.
Poor: Soils wet for long periods of time. They are light gray and generally are mottled from the surface downward, although mottling may be absent or nearly so in some soils.
Drainage Wind
A wind flowing from a higher elevation to a lower elevation.
Duplex
A detached structure containing two dwelling units.
Dwelling Unit
An independent living space within a structure designed and intended for occupancy by not more than one family and having its own housekeeping and kitchen facilities.
Easement
The purchase of partial rights in a piece of land.
Ecologically Critical Areas
Places containing one or more significant natural resources that could be degraded or lost as a result of uncontrolled or incompatible development.
Ecological Planning
The application of ecological knowledge to community, regional, and resource planning.
Ecology
The reciprocal relationship of living things to one another and to their physical and biological environment.
Economic
Of or having to do with the management of the income and expenditures of a household, business, community, or government.
Economic Multiplier
The numerical relationship between an original change in economic activity and the ultimate change in activity that results as the money is spent and respent through various sectors of the economy.
Ecosystem
The interacting system of a biological community and its nonliving surroundings.
Ecotone
Transitional areas between two ecological communities, generally of greater richness than either of the communities it separates.
Elevation
The height of land (in feet or meters) above sea level.
Energy
That which does or is capable of doing work.
Environment
The sum of all external influences that affect the life, development, and survival of an organism.
Environmental Impact Statement (EIS)
A document required of federal agencies by the National Environmental Policy Act for major projects or legislative proposals. It is used in making decisions about the positive and negative effects of the undertaking and lists alternatives. Some states and several other nations also require impact statements.
Environmentally Sensitive Areas
Places vulnerable to negative environmental impacts, such as unstable soils, steep slopes, floodplains, wetlands, and certain plant and animal habitats.
Environmental Thresholds
The level beyond which additional stress to an ecosystem results in a marked decrease in the system’s performance or an adequate change in the system’s structure or both.
Eolian Soils
Soils deposited by the wind.
Erosion
The process of diminishing the land by degrees by running water, wind, ice, or other geological agents.
Erosion, bank
The destruction of land areas by active cutting of stream banks.
Erosion, beach
The retrogression of the shoreline of large lakes and coastal waters caused by wave action, shore currents, or natural causes other than subsidence.
Erosion, gully
The widening, deepening, and headcutting of small channels and waterways due to erosion.
Erosion, rill
The removal of soil by running water with formation of shallow channels that can be smoothed out completely by normal cultivation.
Erosion, sheet
The removal of a fairly uniform layer of soil or materials from the land surface by the action of rainfall and runoff water.
Estuary
A semienclosed coastal body of water that has a free connection with the open sea; it is thus strongly affected by tidal action, and within it seawater is mixed (and usually measurably diluted) with fresh water from land drainage.
Evaporation
The loss of water to the atmosphere from the surface of a soil or a body of water
Evapotranspiration
The sum of evaporation and transpiration during a specific time period.
Exotics
Plants or animals introduced into a community that are not normally constituents of that community.
Factor
The term used to label a group of attributes, such as soil potential, size, compatibility, or scenic quality.
Factor Rating
The number of points assigned to a factor, before weighting.
Factor Scale
The way points are assigned to a factor.
Fault
A fracture line along which movement have occurred, causing the geologic units on either side to be mismatched.
Fauna
Animal life.
Fee Simple
A form of land ownership that includes all property rights, including the rights to develop the land.
Fire Hazard Areas
Places identifies by the U.S. Forest Service and state wildlife management agencies as being particularly susceptible to forest fires.
Flooding
The general and temporary condition of partial or complete inundation of normal dryland areas from the overflow of streams, rivers, and other inland water or from abnormally high tidal water resulting from severe storms, hurricanes, or tsunamis. Also, any relatively high stream flow overtopping the natural or artificial banks in any reach of a stream, or a relatively high flow as measured by either gauge height or discharge quantity.
Floodplain
The area of land adjoining a body of water that has been or may be covered by floodwater.
Flood-Prone Areas
Places identified on the basis of the frequency of flooding.
Floodway
The channel of a river or other watercourse and the adjacent land areas required to carry and discharge a flood of a given magnitude.
Flora
Plant life
Fog
Suspended liquid particles formed by condensation of vapor.
Food Chain
The interconnected feeding relationships of various species that transfer energy from an initial source through a series of organisms.
Forb
Herbs other than true grasses, sedges, and rushes and nongrasslike plants having little or no woody material.
Forestland
Land that is at least 10 percent stocked by trees of any size, and land from which the trees have been removed to less than 10 percent stocking but that has not been developed for other use.
Fragmentation
The breaking up of continuous areas of habitat into smaller parcels. For example, a forest becomes fragmented when sections are cleared for agriculture or when trees are cleared to build roads.
Frost Pocket
A hollow in the topography into which cold air will flow, thereby lowering temperatures in the bottom of the hollow.
Geographic Information System (GIS)
A method of storing geographic information on computers to create a map or a series of maps. Geographic information can be obtained from a variety of sources, including topographical maps, soil maps, aerial and satellite photographs, and remote sensing technology. This information can then be used to create special maps for recordkeeping and decision-making purposes. GIS may be used to maintain maps of protected land or make decisions about which farmland to protect.
Geologic Map
A graphic representation of the rock units and geologic features that are exposed on the surface of the earth.
Geological Hazard Areas
Places characterized by a high frequency of earthquake shaking, landslides, fault displacements, volcanic activity, subsidence, or severe erosion.
Geology
The science dealing with the study of rocks, often in an attempt to learn more about the history of the earth.
Geomorphology
The science dealing with the interpretation of the relief features of the surface of the earth.
Givings
The adding to the value of private property through a government action or actions. Givings include public investments, outright subsidies, tax breaks, and even regulations that give some land uses a competitive edge over others.
Goal
A concise statement of a community or organization’s central aspirations in addressing a problem or an opportunity expressed in terms of a desired state or process that operating programs are designed to achieve.
Grass
Plant species with narrow leaves and jointed stems.
Greenbelt
An area of protected open space around a city or town, or an area that separates two built-up places.
Ground cover
Plants grown to keep soil from eroding.
Groundwater
Water that fills all the unblocked pores of material lying beneath the water table.
Groundwater Recharge Areas
Areas where additions are made to an aquifer by infiltration of water through the land surface.
Group Dynamics
A generic term classifying a variety of interpersonal techniques used to foster group interaction and achievement of group goals and problem-solving techniques designed to clarify substantive issues.
Growth Management
The use of regulations and incentives to influence the rate, timing, location, density, type, and style of development in the community.
Habitat
The sum of environmental conditions in a specific place that is occupied by an organism, population, or community.
Hedgerow
A group of row of trees and shrubs separating two grassy areas.
Herb
Any flowering plant that does not develop a persistent woody stem above ground, including forbs, grasses, and grasslike plants.
Herbicide
A chemical that controls or destroys undesirable plants.
Herbivores
Primary consumers or animals that obtain energy from plants.
Historic, Archaeological, and Cultural Areas
Site important to the heritage of the community, region, state, or nation.
Human Ecology
The interdisciplinary study of human-ecosystem relationships.
Humus
The semistable fraction of the soil organic matter remaining after the major portion of added plant and animal resides has decomposed, usually dark-colored.
Hydrograph
A graph showing the volume of water that passes a point of a stream over a certain period of time.
Hydrologic Cycle
A recurring series of events involving the circulation of water through the environment. The cycle includes precipitation, storage, and evaporation.
Hydrology
The science dealing with the study of groundwater and surface water and the change that occur during the hydrologic cycle.
Impact Fees
A growth management technique that requires a developer to pay for public services necessary for new urban development.
Indicator Species
A species (either plant or animal) generally limited to a particular environment so that is presence will usually indicate that environment or life zone.
Infiltration Rate
The rate of speed at which water flows into soil through small pores.
Insolation
Incoming solar radiation that is absorbed by the land, largely dependent on land-forms and wind direction.
Intrinsic Suitability
The inherent capability of an area to support a particular land use with the least detriment to the economy and the environment.
Introduced Species
A species brought into an area by people; one that is not a native.
Inventory
The gathering of data for future use.
Inversion
An atmospheric condition caused by a layer of warm air preventing the rise of cool air trapped beneath it.
Land Evaluation and Site Assessment (LESA)
A numerical system that measures the quality of farmland. It is generally used to select tracts of land to be protected or developed.
Land Trust
A private, nonprofit conservation organization formed to protect natural resources such as productive farm and forest land, natural areas, historic structures, and recreational areas. Land trusts purchase and accept donations of conservation easements. They educate the public about the need to conserve land, and some provide land use and estate planning services to local governments and individual citizens.
Landscape
All the natural and cultural features such as settlements, fields, hills, buildings, deserts, forests, and water bodies that distinguish one part of the surface of the earth from another part. Usually a landscape is that portion of land or territory which the eye can comprehend in a single view, including all its natural and cultural characteristics.
Landscape Architecture
The art and science of arranging land so as to adapt it most conveniently, economically, functionally, and gracefully to any of the varied wants wants of people.
Landscape Ecology
A study of the structure, function, and change in a heterogeneous land area composed of interacting ecosystems.
Landscape Plan
A written and graphic documentation of a community’s goals, the strategies to achieve those goals, and the spatial consequences of the implementation strategies.
Land Use
The occupation of an area for a particular purpose, such as rangeland or industrial areas.
Land-Use Need
A factor that is essential or beneficial for a particular land use.
Land User
A person using a land resource who may or may not own title to that land.
Langley
A measurement of solar radiation equivalent to one calorie per square centimeter over some increment of time.
Leaching
The process by which nutrient chemicals or contaminants are dissolved and carried away by water or are moved into a lower layer of soil.
Life Cycle
The stages an organism passes through during its existence.
Life Zone
A biotic region with a distinctive flora and fauna. The region is based on climatic conditions, elevation, and other natural factors.
Limestone
A metamorphic rock formed from organic remains.
Limnology
The study of the physical, chemical, meteorological, and biological aspects of fresh water.
Loam
A soil mixture of sand, clay, and silt.
Loess
Predominantly silt-sized particles that have been transported and deposited by the wind.
Lot
A parcel of land under one ownership, used or capable of being used under the subdivision regulations of a zoning ordinance, including both the building site and all required yards and open spaces.
Matrix
A graphic tool that plots two groups of interdependent factors against each other (one in rows and one in columns) to help illustrate their relationships.
Meandering Stream
A stream that follows many S-shaped curves.
Metamorphic Rock
A previously igneous or sedimentary rock that was exposed to conditions that entirely altered its original condition.
Metropolitan Statistical Area (MSA)
Following the 1980 U.S. Census, the term standard metropolitan statistical area (SMSA) was shortened to metropolitan statistical area (MSA). If any area has more than 1 million population and meets certain other specified requirements, then it is termed a consolidated metropolitan statistical area (CMSA), consisting of major components recognized as primary metropolitan statistical areas (PMSAs). In addition there are special New England county metropolitan areas (NECMAs) in that region of the United States. MSAs, PMSAs, and NECMAs are categorized by their population size, as follows:
Level A: Areas of 1 million or more
Level B: Areas of 250,000 to 1 million
Level C: Areas of 100,000 and 250,000
Level D: Areas of less than 100,000
Metropolitan statistical areas are defined in two ways: a city of at least 50,000 population or an urbanized area of at least 50,000 population or an urbanized area of at least 50,000 population with a total metropolitan area population of at least 100,000. MSAs are defined in term of counties, except in the six New England states where they are defined in terms of cities and towns. In addition to the county containing the main city, an MSA also includes additional counties having strong economic and social ties to the central county.
Microclimate
The climate from the surface of the earth to a height at which the local effects of the earth can no longer be distinguished from the general climate.
Migratory Animals
Animals that periodically pass from one region or climate to another for feeding or breeding purposes.
Mineral Extraction Areas
Places that contain minerals or materials of commercial quality and quantity that include, but are not limited to, sand, gravel, clay, peat, rock, and ores.
Mission Statement
A brief declaration of the purpose for which a unit exists and functions. A mission statement can help define the purpose of a plan.
Moratoriums
The prevention of the issuance of building permits until urban service capacity levels are attained or until plans and ordinances are completed.
Morphology
The study of surfaces and forms.
Multifamily Dwelling
A building containing three of more dwelling units.
Multiple Use
Harmonious use of land for more than one purpose, such as grazing of livestock, wildlife production, recreation, and timber production. It is not necessarily the combination that will yield the highest economic return or greatest unit output.
Natural Ecological Areas
Places with ecosystem units that are either superlative examples of their type of areas that perform a vital function in maintaining the ecological integrity and environmental quality of a larger region.
Natural Hazard Critical Areas
Places in which incompatible development may result in the loss of life or property or both.
Natural Selection
The process of survival of the fittest by which organisms that adapt to their environment survive and those that do not disappear.
Natural System
The biophysical factors, such as geology, soils, and wildlife.
Natural Wildlife Habitat Areas
Places essential to the preservation of game species or unique, rare, or endangered species.
Neighborhood Planning Council
A locally based organization that permits citizen participation in policy decisions and in planning issues affecting their immediate geographic area.
Niche
An area that provides the necessary elements for the existence of a particular organism
Nominal-Group Workshop
A citizen-participation technique based on the concept that people think most creatively while working in a group.
Nonconforming Use
Any lawful use of activity involving a building or land occupied or in existence at the effective date of a zoning ordinance that does not conform to the principal, accessory, or condition uses permitted in, or the density provisions of, the zoning district in which it is located.
Non-Point-Source Pollution
Caused by residuals carried into streams, lakes, and estuaries by surface water as well as to groundwater zones by infiltration and percolation. These pollutants do not result from a direct release from a pipe or channel.
Nutrients
Elements or compounds essential to the growth and development of living things: carbon, oxygen, nitrogen, potassium, and phosphorus.
Objective
A clear and specific statement of planned results to be achieved within a stated time period.
Oceanography
The study of the sea in all its physical, chemical, geological, and biological aspects.
Omnivores
Animals that obtain energy from plants and other animals.
Open Space
A relatively undeveloped green or wooded area provided usually within an urban development to minimize the feeling of congested living.
Organic
Referring to or derived from living organisms. In chemistry, it is any compound containing carbon.
Organic matter
Matter derived from living matter.
Organism
Any living things.
Organization Development
A discipline involved in intervening in social networks to foster higher levels of cohesion and effectiveness.
Osmosis
The tendency of a fluid to pass through a permeable membrane (such as the wall of a living cell) into a less concentrated solution so as to equalize concentrations on both sides of the membrane.
Parent Material
The unconsolidated and chemically weathered mineral or organic matter from which soils are developed.
Patch
A spatially separate instance of a given type of habitat.
Pedology
The study of soils.
Pedon
A three-dimensional soil sampling unit from 1 to 10 square meters, large enough so the nature of its soil horizons can be studied and the range of its properties identified.
Perceptually and Culturally Critical Areas
Places containing one or more significant scenic, recreational, archaeological, historical, or cultural resources that could be degraded or lost as result of uncontrolled or incompatible development.
Perched Water Table Condition
A layer of soil separated above the saturated zone by an impermeable layer
Percolation
The downward movement of water in a soil
Perennial Plant
A species of plant that lives longer than 2 years
Performance Standards
Criteria that are established and must be met before a certain use will be permitted. These criteria, or standards, may be a set if economic, environment, or social factors or any combination of these factors.
Permeability
The rate at which water can move through soil
Pesticide
Any substance used to control pests ranging from rats, weeds, and insects to algae and fungi.
pH
A measure of the acidity or alkalinity of a material, soil, or liquid, pH is represented on a scale of 0 to 14, with 7 being a neutral state, 0 most acid, and 14 most alkaline.
Photogrammetry
The art of science of obtaining reliable measurements through photography.
Phyllite
A rock similar in composition to silt and schist.
Physical
In ecological planning, the abiotic elements of the environment, including geography, physiography, soils, hydrology, and climate.
Physiography
The science dealing with the study of physical features of the land, in particular slope and elevation.
Planned Unit Development (PUD)
A tract of land that is controlled by one entity and is planned and developed as a whole, either all at once or in programmed stages. PUDs are developed according to detailed site plans and may incorporate both residential and commercial land uses. They generally include improvements such as roads and utilities.
Planning
The use of scientific, technical, and other organized knowledge to provide choices for decision making as well as a process for considering and reaching consensus on a range of options.
Planning Commission
An appointed citizen body that advises elected officials on such matters as the comprehensive plan, zoning ordinances, and subdivision regulations.
Planning, Programming, and Budget System (PPBS)
A complex annual budget system that involves the linkage of programs to the budgeting process.
Planning Staff
The professional staff for the planning commission.
Plant Community
An association of plants characterized by certain species occupying similar habitats.
Plat
A map or plan, especially of a piece of land divided into building lots.
Plateau
A large, flat area of land that is higher in elevation than some adjacent land.
Police Power
The right of government to restrict an owner’s use of property to protect the public health, safety, and welfare. Restrictions must be reasonable and be conducted according to due process.
Policy
A definitive course or method of action selected by a governmental agency, institution, group, or individual from among options and in light of given conditions to guide and usually determine present and future decisions.
Preferential Tax Policies
Favorable taxation of land in exchange for an agreement to use that land for a certain use, such as agriculture, or for open spaces.
Prime Agricultural Land
Farmland that has a gentle slope and well-drained soils and requires a minimum of conservation practices. It is the easiest land to farm. Class I and Class II soils, as defined by the Natural Resources Conservation Service of the U.S. Department of Agriculture, are considered prime agricultural soils.
Process
The action of moving forward progressively from one point to another on the way to completion.
Primary Consumers
Herbivores or animals that obtain energy from plants.
Pristine
Pure and untouched.
Producers
Organisms that can use solar energy to convert inorganic substances into organic substances.
Profile
A graphic tool that shows a portion of the surface of the earth and the features on this portion.
Project Planning
Designing a solution to a specific problem such as a dam, highway, harbor, or a single building or group of buildings.
Public Hearing
An open forum where statements become part of official records. Public hearings are often required by law.
Public Opinion Poll (Preference Survey)
A means of gathering information, attitudes, and opinions from a large number of people.
Purchase of Agricultural Conservation Easements (PACE)
PACE programs pay farmers to keep their land available for agriculture. Landowners sell an agricultural conservation easement to a qualified government agency or private conservation organization. Landowners retain full ownership and use of their land for agricultural purposes. PACE programs do not give government agencies the right to develop land. Development rights are extinguished in exchange for compensation. PACE is also known as purchase of development rights (PDR) and as agricultural preservation restriction (APR) in Massachusetts.
Purchase of Development Rights (PDR)
The property owner’s development interests are relinquished to the purchaser of the rights, who can be a government or nongovernmental entity, such as a land trust. The purchaser then can limit the development of the property to encourage agricultural, open space, or environmental uses.
Putative Species
The species expected to occur in an area based on habitat requirements..
Rain Shadow
An area that has decreased precipitation because it is to the leeward side of mountains.
Rangeland
Land in grass or other long-term forage growth of native species used primarily for grazing. It may contain shade trees or scattered timber trees with less than 10 percent canopy. It includes grasslands, land in perennial forbs, sagebrush land, and brushland other than sage. The term nonforest range is used to differentiate the nonforest range from the forest range when both are being discussed.
Receiving Area
Areas designated to accommodate development transferred from agricultural or natural areas through a transfer of development rights program.
Recharge
Process by which water is added to the zone of saturation, as recharge of an aquifer.
Recreation
Any experience voluntarily engaged in largely during leisure (discretionary time) from which the individual derives satisfaction.
Region
(1) An uninterrupted area possessing some kind of homogeneity in its core but lacking clearly defined limits.
(2) A governmental jurisdiction or designation.
(3) A frame for multidisciplinary research: a demand for the integration of data from many realms of ecological reality and, therefore, an opportunity for specialists to work together on theoretical conceptions of human ecology as a synthesis.
Regolith
The predominantly loose surficial material overlaying bedrock. It is roughly equivalent to what engineers term soil and may contain or be capped by a true soil pedon, as used by soil scientists.
Remote Sensing
The detection, identification, and analysis of objects or features through the use of imaging devices located at positions remote from the objects of investigation.
Resident
Animals that remain in one region or climate throughout the year.
Residium
Unconsolidated and partly weathered mineral materials accumulated by disintegration of consolidated rock in place.
Resource
A substance or object required by an organism for normal maintenance, growth, and reproduction. If a resource is scare relative to demand, then it is referred to as a limited resource. Nonrenewable resources (such as space) occur in fixed amounts and can be fully utilized; renewable resources (such as food) are produced at a fixed rate with which the rate of exploitation attains an equilibrium.
Resource Production Critical Areas
Places that provide essential products supporting either the local economy or economies of a larger scale.
Restrictive Agreement
A type of differential assessment that requires a landowner to sign a contract to keep land in agricultural use for 10 years or more as a condition or eligibility for tax relief. If the landowner gives notice of intent to terminate the contract, assessed value of the property increases during the balance of the term to the full fair market value.
Riparian
Relating to a habitat on the banks of streams, rivers, and lakes.
River Basin
The land area drained by a river and its tributaries.
Rubble
A mass of broken stones and rocks, often at the base of a cliff.
Runoff
Water from rain, snowmelt, or irrigation that flows over the ground surface and returns to streams.
Sand
Soil particles between 0.05 and 2.0 millimeters in diameter.
Scale
The relative size of an area of interest. If the focus on relatively small areas (for example, the area around a house or a single subdivision), the focus is fine scale. If the focus is on a much larger area (i.e., a county or watershed), than it is a coarse scale.
Scenic Areas
Places that contain natural features of sufficient aesthetic quality to warrant their preservation.
Scientific Areas
Places of geological interest or places that present ecological processes warranting study.
Score
This term is used for the total of all factor ratings.
Secondary Consumer
Carnivore or animals that obtain energy from other animals.
Septic Tank
An enclosure in which the organic solid matter of continuously flowing wastewater is deposited and retained until it has been disintegrated by anaerobic bacteria.
Service Districts
The division of a jurisdiction into areas based on the level of urban and rural services, with different rates of taxation.
Setback
A zoning provision requiring new homes to be separated from existing farms by a specified distance and vice versa.
Shale
A sedimentary rock formed from tightly packed clays and silts.
Silt
Fine soil particles between 0.05 and 0.0002 millimeter in diameter that can be picked up by air or water and deposited as sediment.
Single-Family Dwelling
A detached building containing one dwelling unit.
Slope
The incline of the land surface, usually expressed in percentage of slope. Often slopes are expressed as follows: 0-3 Percent - Nearly Level 3-7 Percent - Gently Sloping 7-12 Percent - Moderately Sloping 12-25 Percent - Strongly Sloping 25-40 Percent - Steeply Sloping 40-70 Percent - Very Steeply Sloping 70-100 percent and above - Extremely Steeply Sloping
Slope Wind
Winds flowing up or down slopes along a temperature gradient.
Social
Relating to human society and the interactions of the community.
Sociocultural
A combination of the social and the cultural characteristics of an area.
Soil
A natural, three-dimensional body on the surface of the earth that supports plants and has properties resulting from the integrated effect of climate and living matter acting upon parent material as conditioned by relief over periods of time.
Soil Association
Soils of different series found in the same area.
Soil Catena
A group of related soils that have developed from the same parent material but differ in drainage class due to different locations on a slope.
Soil Depth
The depth of soil material that plant roots can penetrate readily to obtain water and nutrients. It is the depth to a layer that, in physical or chemical properties, differs from the overlying material to such an extent as to prevent or seriously retard the growth of roots or penetration of water. The depth classes are (1) very deep, more than 60 inches; (2) deep, 40 to 60 inches; (3) moderately deep, 20 to 40 inches, (4) shallow, 10 to 20 inches; and (5) very shallow, 1 to 10 inches.
Soil Profile
A vertical section of the soil through all its horizons and extending into the parent material.
Soil Series
Soils from the same parent material having similar horizon characteristics.
Soil Texture
The relative proportions of sand, silt, and clay particles in a mass of soil. The basic textural classes, in order of increasing proportion of fine particles, are shown in the following chart.
Sandy Soils
Coarse-textured soils Sand Moderately coarse-textured soils Sandy loam Fine sandy loam
Loamy Soils
Medium-textured soils Very fine sandy loam Loam Silt loam Silt Moderately fine-textured soils Clay loam Sandy clay loam Silty clay loam
Clayey Soil
Fine-textured soils
Sandy clay
Silty clay
Clay
Soil Types
Soils within a series having the same texture
Solar radiation
The energy from the sun that reaches the earth.
Solum
The upper and most weathered part of the soil profile; and A and B horizons.
Species
A group of closely related organisms potentially able to reproduce viable offspring
Species Diversity
The number of different species occurring in a location or under the same conditions
Sprawl
Unplanned development of open land.
Standard
A statement that describes a condition when job is done properly. Standards show how well something should be done rather than what should be done.
Strategy
The approach and/or methods through which problems are solved or minimized and objectives are achieved.
Stream
A general term for a body of flowing water. In hydrology, the term is generally applied to the water flowing in a natural channel as distinct from a canal. More generally, as in the term stream gauging, it is applied to the water flowing in any natural or artificial channel.
Stream, ephemeral
A stream that flows only in response to precipitation
Stream, intermittent
A stream that flows only part of the time or through only part of its reach
Stream orders
First-order streams are primary drainageways. Second-order streams are the confluence of two first-order streams. Third-order streams are the confluence of two second-order streams, and so on.
Stream, perennial
A stream that flows continuously
Street
The entire width between property boundary lines of every way that provides for public use for the purpose of vehicular and pedestrian traffic and the placement of utilities.
Strip-Cropping
Growing crops in a systematic arrangement of strips or bands that serve as barriers to wind and water erosion.
Structures, heavy
A building of generally great weight and size, such as a mill or factory.
Structures, light
A building of generally slight weight and size, such as a residence.
Subdivision
The division of a lot, tract, or parcel of land into two or more lots, plats, sites, or other divisions of land for the purpose, whether immediate or future, of sale or building development.
Subdivision Regulation
The legal requirements pertaining to the subdivision of land.
Subsoil
The B soil horizon; the layer of soil below the layer in which grass roots normally grow.
Succession
The orderly progressive replacement of one community by another until a relatively stable community occupies an area.
Suitability Analysis
The process of determining the fitness of a given tract of land for a defined use. Suitability is often used interchangeably with capability.
Surface Water
Water that remains on the top of land, such as lakes, rivers, streams, and seas.
Sustainability
The maintenance of the health and productivity of ecosystems, which provide a variety of benefits over time.
Sustainable Development
Development that meets the needs of the present without compromising the ability of future generations to meet their own needs.
Swale
An elongated depression in the land.
Synthesis
The combining of all the parts to form an inter-relating whole
Taking
An illegal government appropriation of private property or property rights. Traditionally, takings law has addressed physical seizures of land, but regulations that deprive landowners of certain property rights may also result in a taking in special circumstances. Courts decide whether a particular government action constitutes a taking.
Task Force
An agency-sponsored citizens’ committee with a specific task and charge usually related to a single problem or subject.
Technical Advisory Committee (TAC)
A group of individuals with specific expertise, usually from various disciplines, brought together by an agency for giving advice and consultation.
Temperature Gradient
The difference in temperature along some horizontal distance or up a vertical parcel of air.
Terracing
Dikes built along the contour of agricultural land to hold runoff and sediment, thus reducing erosions.
Topoclimate
The term used when the topographic variations of the land on microclimate are considered
Topography
The physical features of a surface area, including relative elevations and the positions of natural and artificial features.
Town Meeting
The traditional New England meeting of the people of a town.
Transfer of Development Rights (TDR) Program
A program that allows landowners to transfer the right to develop one parcel of land to a different parcel of land to prevent farmland conversion. TDR programs establish “sending areas” where land is to be protected by agricultural conservation easements and “receiving areas” where land may be developed at a higher density than would otherwise be allowed by local zoning. Landowners in the sending area sell development rights to landowners in the receiving area, generally through the private market. When the development rights are sold on a parcel, a conservation easement is recorded or enforced by the local government. In some cases, the local government may establish a “TDR Bank” to buy and sell development rights. The development rights created by TDR programs are referred to as transferable development rights (TDRs) or transferable development credits (TDGs)
Transpiration
The loss of water to the atmosphere from plants.
Tree
A woody, perennial plant with a single main stem.
Trophic Levels
The different levels through which energy flows from producers to consumers
Understory
Herbs and shrubs that grow beneath a forest canopy
Upzoning
A change in the zoning for a particular area that results in higher residential densities. For example, a change from a zoning ordinance that requires 100 acres (40.47 hectares) per dwelling to an ordinance that requires 25 acres (10.1 hectares) per dwelling is an upzoning.
Urban Growth Boundary
Line to which urban areas may grow based on population projections and physical conditions of the area.
Urban Morphology
The study of the city as human habitat.
USGS Map
U.S. Department of Interior Geological Survey map.
Valley Wind
Winds flowing up or down valleys along temperature gradients.
Variance
A special situation that creates a need to deviate from the established zoning ordinances and requires review by a board of adjustment or similar review agency.
Vegetation
Plant life: trees, shrubs, herbs, and grasses.
Vegetation Type
A classification given to plants that are found in the same place on a landscape.
Ventilation
The circulation of fresh air across the land, largely dependent on land-forms and wind direction.
Voluntary Covenants
Agreements that limit what can be done with property.
Wash
An ephemeral stream; that is, one that flows only during or after rainstorms. Called an arroyo in Spanish.
Water
A transparent, odorless, tasteless liquid; a compound of hydrogen and oxygen (H2O) that freezes at 32F (OC) and boils at 212F (100C). Most water is more or less in an impure state, and constitutes rain, oceans, lakes, rivers, and other such bodies. It contains 11.188 percent hydrogen and 88.812 percent oxygen by weight.
Water Balance
The ratio of water lost from a system and brought into a system.
Water Quality Areas
Aquifer recharge areas, headwaters, stream corridors, and wetlands that function as a natural filter for surface waters.
Watershed
A drainage area separated from other drainage areas by a dividing ridge.
Water Table
The upper surface of groundwater or that level below which the soil is saturated with water.
Weighted Factor Rating
This term is used to denote the factor rating after weighting.
Weighting
This term refers to assigning a weight (for example, 0-1.0) to each factor in order to recognize the relative importance of each factor.
Wilderness Recreation Areas
Isolated tracts of land that are large enough to support recreational activities like camping, hiking, and canoeing.
Wildlife
Animals that are neither human nor domesticated.
Windchill
The relationship between body heat loss and the cooling power of different wind and temperature combinations.
Zone
An area or areas of the community or county in which certain land uses are permitted and other uses are prohibited by the zoning ordinance. Common zones are residential, commercial, industrial, and agricultural.
Zone Change
An action taken by the local governing body to change the type of zoning on one or more pieces of land. For example, a zone change or rezoning could be from A-1, agricultural, to C-2, medium-density commercial. A zone change for specific properties can happen in two ways. A property owner may ask for a zone change, which is a quasi-judicial action. Otherwise, either the planning commission or the governing body may seek a zone change through a legislative action. If a zone change is approved, the zoning map must also be amended. Some zone changes may required amending the comprehensive plan map.
Zoning
Land-use controls such as limiting the use to which land in each area may be put, minimum lot size, and building types.
