GR 420 Exam 2 | GR 420 - Spatial Analysis with GIS, Quizzes of Geography

Download GR 420 Exam 2 | GR 420 - Spatial Analysis with GIS and more Quizzes Geography in PDF only on Docsity! TERM 1 Buffering DEFINITION 1 Setting a region less than or equal to a specified distance from one or more features TERM 2 What are types of buffers used with Vector data? DEFINITION 2 Polygon buffers (doughnut, setback) TERM 3 How are buffers used? DEFINITION 3 to show an area around a point, line, or polygon TERM 4 What is Dissolve? DEFINITION 4 combines adjacent polygon features based on a single predetermined attribute TERM 5 What is Append? DEFINITION 5 Combines the spatial extent of two or more layers TERM 6 What is Select? DEFINITION 6 Creates an output layer from a selected feature TERM 7 What is Merge? DEFINITION 7 Combines features into a single feature TERM 8 What is the history of overlay analysis? DEFINITION 8 Mylar sheets TERM 9 What is a Clip? DEFINITION 9 A clip is when you use a "cookie cutter" overlay to cut out data from one layer via a bounding polygon TERM 10 What is a Union? DEFINITION 10 Overlay that includes all the data from the bounding and data layer TERM 21 What is reclassification? DEFINITION 21 assigning a new class or range value from a table, range of numbers, or conditional test. (if x then y) TERM 22 Buffering in a raster environment DEFINITION 22 Binary, (in or out), specified distance like vector TERM 23 Map Algebra DEFINITION 23 Unary operations apply to one layer, binary operations, higher level operations may involve many layersSet-based algebra for manipulating geographic dataCannot work with incompatible cell sizes TERM 24 How is Clip used? DEFINITION 24 Overlay template extracts clip from input raster TERM 25 How is local raster calculation operationalized? DEFINITION 25 Cell by cell addition, subtraction, multiplication, divisionWhy can this lead to confusing answers?If combination of cells lead to same answer TERM 26 What is a majority filter? mean filter? Low Pass? DEFINITION 26 If surrounded by 4 similar cells, change center to majorityAverage of cellsaccenuateslines and real data TERM 27 What is a Cost Surface? DEFINITION 27 fixed cost and distance. Used to represent cost to move along a path. TERM 28 What are commonly used terrain variables? DEFINITION 28 Height, slope, aspect, uplsope area, viewshed etc TERM 29 What is a DEM DEFINITION 29 Digital Elevation Model TERM 30 Why are slope and aspect important? DEFINITION 30 Determines steepness and direction water will flow TERM 31 What are profile and plan curvature? DEFINITION 31 Parallel and perpendicular to slope direction TERM 32 Explain how flow direction can be determined on a DEM DEFINITION 32 By looking at aspect TERM 33 What is a sink in a DEM? DEFINITION 33 Usually an error from too much accuracy, sometimes real. A place where water will get trapped / drain to TERM 34 How do scale and resolution affect slope in a spatial model? DEFINITION 34 with too low of a scale or resolution or both, a slope cannot be accurately determined on a smaller scale. Too accurate and there will be errors ( a log can form a sink, whereas water will actually flow around it) TERM 35 What are contour lines? DEFINITION 35 Areas of uniform elevationPopularized on maps due to cheapness TERM 46 Adaptive DEFINITION 46 Greaters sampling efficiencyCan be more costly TERM 47 Nearest Neighbor DEFINITION 47 Unsampled area given closest sampled value TERM 48 Inverse Distance weighted interpolation DEFINITION 48 Estimates values based on distance to nearby points TERM 49 Trend Surface / Simple Spatial Regression DEFINITION 49 spatial regression that involves fitting a statistical model through measured points TERM 50 kriging DEFINITION 50 statistically based estimator of spatial variables, baes on regionalized variable theory TERM 51 Spatial autocorrelation DEFINITION 51 tendency of near things to be like eachother TERM 52 Morans I DEFINITION 52 Way of measuring spatial autocorrelation, measures feature location and values simulatenously TERM 53 Accuracy DEFINITION 53 Correctness TERM 54 RMSE MAE MBE DEFINITION 54 Root mean square errorMean absolute errormean bias error TERM 55 Bootstrapping DEFINITION 55 random sampling with replacement TERM 56 core area mapping DEFINITION 56 primary area of influence or activity TERM 57 mean center mean circle DEFINITION 57 average x and y coords of all sample pointsmean circle defined by radius measured from mean center TERM 58 Convex Hull DEFINITION 58 minimum convex polygon (created by lines connecting all outside points that completely enclose all points TERM 59 characteristics hull polygon DEFINITION 59 created by a set of minimum bounding triangles TERM 60 Cartography DEFINITION 60 art and science of representing spatial information on a map