GIS - Maps & Statistics Flashcards
Datum
In surveying and geodesy, a datum is a set of reference points on the earth’s surface against which position measurements are made, and (often) an associated model of the shape of the earth (reference ellipsoid) to define a geographic coordinate system.
Mean
The mean (average) of a data set
median
the median is the middle value when a data set is ordered from least to greatest.
mode
The mode is the number that occurs most often in a data set.
Management Information Systems (MIS)
Management Information Systems (MIS) is the study of people, technology, organizations, and the relationships among them.
b2b
Business-to-business is a situation where one business makes a commercial transaction with another.
geographic information system (gis)
A geographic information system is a conceptualized framework that provides the ability to capture and analyze spatial and geographic data.
polygon
When GIS software is used to draw the outline of a lake on a map, the resulting shape is known as a polygon. The term ‘area’ is also used sometimes, instead of polygon. A polygon is one of three feature types – others are line and point – with which almost all spatial data is depicted in GIS.
node
In a geodatabase, the point representing the beginning or ending point of an edge, topologically linked to all the edges that meet there.
attribute
A. attribute. [data models] Nonspatial information about a geographic feature in a GIS, usually stored in a table and linked to the feature by a unique identifier. For example, attributes of a river might include its name, length, and sediment load at a gauging station.
elevation
Elevation is distance above sea level. Elevations are usually measured in meters or feet. They can be shown on maps by contour lines, which connect points with the same elevation; by bands of color; or by numbers giving the exact elevations of particular points on the Earths surface.
vector & raster
The old GIS adage “raster is faster, but vector is corrector”
comes from the two different fundamental GIS models:
vector and raster. Each of these models has its own
advantages and disadvantages. The vector model uses
points and line segments to identify locations on the earth
while the raster model uses a series of cells to represent
locations on the earth. T
1 yard = ? feet
3 feet
resolution
The scale of a map is the ratio of a distance on the map to the corresponding distance on the ground.
projections & types
A projection is the means by which you display the coordinate system and your data on a flat surface, such as a piece of paper or a digital screen. Mathematical calculations are used to convert the coordinate system used on the curved surface of earth to one for a flat surface. 4 types- Conic, cylindrical, planar, polar
datum (world vs. 1983)
The North American 1983 datum (NAD83) uses the Geodetic Reference System (GRS80) ellipsoid while the World Geodetic System of 1984 (WGS84) uses the WGS 84 ellipsoid. The dimensions of these ellipsoids differ slightly.
CAD
Computer-aided design is the use of computers to aid in the creation, modification, analysis, or optimization of a design. CAD software is used to increase the productivity of the designer, improve the quality of design, improve communications through documentation, and to create a database for manufacturing.
Ian mcCard
almost father of GIS layers
Geocoding
Geocoding is the process of transforming a description of a location—such as a pair of coordinates, an address, or a name of a place—to a location on the earth’s surface. You can geocode by entering one location description at a time or by providing many of them at once in a table.
Georeferencing
Georeferencing is the name given to the process of transforming a scanned map or aerial photograph so it appears “in place” in GIS. By associating features on the scanned image with real world x and y coordinates, the software can progressively warp the image so it fits to other spatial datasets.
Registering
Data registration provides the server with a list of locations for your web services’ source data. Data registration helps you validate that your services will reference data locations known and approved by the server administrator.
Land based Classification System (zoning)
colors - yellow = residential; red =commercial
type of GIS analysis
site, economic, environmental, trend analysis
Triangular Irregular Networks (TIN modeling)
Triangular irregular networks (TIN) have been used by the GIS community for many years and are a digital means to represent surface morphology. TINs are a form of VECTOR-based digital geographic data and are constructed by triangulating a set of vertices (points).
metes and bounds
Metes and bounds are the boundaries of a parcel of real estate that identified by its natural landmarks. Metes and Bounds landmarks are often used in a “legal description” of a land.
PLSS, Ordinance of 1785
Public Land Survey System: The Public Land Survey System (PLSS) is a way of subdividing and describing land in the United States. … The PLSS typically divides land into 6-mile-square townships. Townships are subdivided into 36 one-mile-square sections.
Township, Section, Range
Study how to find this: https://web.gccaz.edu/~lynrw95071/Township%20Range%20Explanation.html
USGA Maps
USGS is a primary source of geographic information system (GIS) data. The best known USGS maps are the 1:24,000-scale topographic maps, also known as 7.5-minute quadrangles. From approximately 1947 to 1992, more than 55,000 7.5-minute maps were made to cover the 48 conterminous states.
orthophoto maps & quads
A digital orthophoto quadrangle (DOQ)–or any orthoimage–is a computer-generated image of an aerial photograph in which displacements (distortions) caused by terrain relief and camera tilts have been removed. It combines the image characteristics of a photograph with the geometric qualities of a map.
Unlike an aerial photograph, an orthoimage has a uniform scale, so it can be used as a base map onto which other map information is overlaid. It is possible to measure directly on an orthoimage, just like other maps.
flood, 100 year
A standard adopted by the Federal Emergency
Management Agency to identify
areas where there exists a 1 percent annual
chance of a flood occurring.
base flood elevation
The Base Flood Elevation (BFE) is an elevation indicated on the Preliminary Flood Insurance Rate Map defining the elevation of a potential flood.
density
The number
of dwelling units permitted per net
acre of land.
random sampling
Random sampling is a part of the sampling technique in which each sample has an equal probability of being chosen. A sample chosen randomly is meant to be an unbiased representation of the total population.
systematic sampling
Systematic sampling is a statistical method involving the selection of elements from an ordered sampling frame. The most common form of systematic sampling is an equiprobability method. In this approach, progression through the list is treated circularly, with a return to the top once the end of the list is passed.
stratified sampling
In statistics, stratified sampling is a method of sampling from a population which can be partitioned into subpopulations. In statistical surveys, when subpopulations within an overall population vary, it could be advantageous to sample each subpopulation independently
cluster sampling
In cluster sampling, researchers divide a population into smaller groups known as clusters. They then randomly select among these clusters to form a sample. Cluster sampling is a method of probability sampling that is often used to study large populations, particularly those that are widely geographically dispersed.
probabilistic sampling
probability sampling is defined as a sampling technique in which the researcher chooses samples from a larger population using a method based on the theory of probability. For a participant to be considered as a probability sample, he/she must be selected using a random selection.
non-probabilistic sampling
Examples of nonprobability sampling include: Convenience, haphazard or accidental sampling – members of the population are chosen based on their relative ease of access.
quota samples
Quota sampling means to take a very tailored sample that’s in proportion to some characteristic or trait of a population. For example, you could divide a population by the state they live in, income or education level, or sex. … Care is taken to maintain the correct proportions representative of the population.
snowball samples
Snowball sampling is where research participants recruit other participants for a test or study. It is used where potential participants are hard to find. It’s called snowball sampling because (in theory) once you have the ball rolling, it picks up more “snow” along the way and becomes larger and larger.
convenience samples
A convenience sample is a type of non-probability sampling method where the sample is taken from a group of people easy to contact or to reach.
nominal variable
A nominal scale describes a variable with categories that do not have a natural order or ranking. You can code nominal variables with numbers if you want, but the order is arbitrary and any calculations, such as computing a mean, median, or standard deviation, would be meaningless. Examples of nominal variables include:
genotype, blood type, zip code, gender, race, eye color, political party
https://www.graphpad.com/support/faq/what-is-the-difference-between-ordinal-interval-and-ratio-variables-why-should-i-care/
ordinal variable
An ordinal scale is one where the order matters but not the difference between values. Examples of ordinal variables include:
socio economic status (“low income”,”middle income”,”high income”), education level (“high school”,”BS”,”MS”,”PhD”), income level
interval variable
An interval scale is one where there is order and the difference between two values is meaningful. Examples of interval variables include:
temperature (Farenheit), temperature (Celcius), pH, SAT score (200-800), credit score (300-850)
ratio variable
A ratio variable, has all the properties of an interval variable, and also has a clear definition of 0.0. When the variable equals 0.0, there is none of that variable.
Examples of ratio variables include:
enzyme activity, dose amount, reaction rate, flow rate, concentration,
meta-analysis
A meta-analysis is a statistical analysis that combines the results of multiple scientific studies. Meta-analysis can be performed when there are multiple scientific studies addressing the same question, with each individual study reporting measurements that are expected to have some degree of error.
Variance
a measure of dispersion around the mean calculated as the average of the sum of the squared deviations from the mean.
standard deviation
the square root of the variance
Normal distribution
a probability distribution that is symmetrical around the mean, bell shaped, and with a standardized relationship between the mean and variance called a score.
confidence interval
a range of values that includes a certain population parameter (e.g., the mean) with a given probability
test of hypothesis
probability test that relates a sample based estimate to a population related hypothesis, and allows for either acceptance or rejection of this hypothesis.
Statistical Process Control
A collection of problem solving tools useful in achieving process stability and improving capability through the reduction in variability. CIP is a Capital Improvement Program, which is normally a list of ranked projects with descriptions, costs, projected delivery dates and potential funding sources.
regression analysis
statistical technique which provides an estimate of one
variable based on a linear function of another. The coefficient of determination or varies between 0 and I and indicates the percentage of the variance in the dependent variable explained by the independent variable.
Capital vs. operating budget
the operating budget entails the everyday expenditures for salaries, supplies and maintenance. Capital budgets (often referred to as CIP) generally reflect one-time major project expenditures to be used over a long period of time.
Linear programming
a mathematical technique used to find the optimum design solution for a project.
PERT (Program Evaluation and Review Technique
Scheduling technique that graphically (chart) depicts the interrelationships of the tasks that constitute the project. PERT is designed to aid in planning and controlling both cost and time
critical path programming
used to determine which particular steps in a
project will be most “critical” to keeping the project going, e.g. it frequently is used to manage the scheduling of construction projects.
fiscal impact analysis
determines whether a particular project or scale of development within a community will generate sufficient revenues to defray the necessary public service costs. Used to evaluate overall financial implications to local governments of alternative patterns and densities of land development.
cost revenue analysis
focuses exclusively on the costs and revenues
associated with a specific form of growth. The result of such an analysis is a statement of net governmental surplus or deficit expressed in purely financial terms.
present value
needed when benefits/costs are not consistent overtime
cost benefit analysis
compares both the tangible and intangible
(externalities) costs and revenues of a particular project or program compares what a community gains from the project benefits to what the community must forego in order to achieve it. Any project with a ratio higher than I provides more benefits than costs.
shift share
a given region may change at a rate (faster or slower) than the
national average
Location quotient
technique for comparing a region’s percentage share of a
particular activity or industry with its percentage share of the local versus National market.
Equivalent Uniform Annual Cost
A particularly useful financial analysis tool which allows alternatives with different lines and different costs throughout those lines to be compared fairly. The method converts the variable costs incurred to a uniform series of annual cash flows.
