Groupin!l Tools: RECLASS Chanqe cell values based on remap table assiqnments REGIONGROUP Groups cells of the same value that touch each other.. Distance Tools: EXPAND Expands user-specif
Trang 1Grid Exercises
INTRODUCTION
In this chapter, you can test your understanding of GIS tools for application of problcm-solving in the Grid GIS world The following table summarizes the Grid GIS tools that were covered in Chapter 8.
Grid Arithmetic 0 erators:
* Multiplication
Selection Tools:
TEST Returns 1 /0 based on loqical query
SELECT Returns original / NODATA based on loqical query
CON Returns user-specified values based on loqical query
Groupin!l Tools:
RECLASS Chanqe cell values based on remap table assiqnments
REGIONGROUP Groups cells of the same value that touch each other
Distance Tools:
EXPAND Expands user-specified cell values (analoqous toBUFFER ).
EUCDISTANCE Computes the distance to closest non-NODATA cell for each cell
I
Optimal Path Tools:
COSTDISTANCE Estimates the minimum accumulative cost to resource cells
COSTPATH Estimates the least cost path from source to destination cells
TOPo!lraphic Tools:
SLOPE Estimates rate of maximum slope chanqe for each cell
ASPECT Estimates the slope direction for each cell
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© 2002 Taylor & Francis
Trang 2REAL ESTATE APPLICATION
You have grids of elevation, roads, and ownership You want to find land owned by the Fairbanks Northstar Borough that is above 500 feet elevation (out of the ice fog), on
a easterly, southerly, or westerly slope, and within 100 meters of a road Your elevation values is in meters.
Fill in the following flowchart with the appropriate Grid tools:
I ELEVATION
1= owned by FBKSNSB 1= within 100 meters O=owned by other O=too far from road NO-ICEFOG
1= elevation> 500ft
O=too low in elevation
WARM_SLOPE 1= owned by FBKS and 1=Aspect from 90 to 270 within 100 m of road O=Aspect from northerly slope O=other
SITES 1=Aspect from 90 to 270 above 500ftelevation owned by FBKSNSB and within 100 m of road
© 2002 Taylor & Francis
Trang 3WATERSHED APPLICATION
You have a grid of vegetation types, and a grid of watersheds You want a table showing the area of each watershed and the area of black spruce in each watershed Each grid cell
is 25 by 25 meters.
Fill in the following flowchart with the appropriate grid operations to solve your GIS problem:
1=White Spruce 0= No 2= Black Spruce 1= Yes, a black 3= Aspen/Birch spruce cell
WATERSHEDS 1= Rock Creek 2= Glade Creek 3= Moose Creek
lumn called Ha 1= Blk Spruce in-Rock Creek
cell area into hectares 3= Blk Spruce in Moose Creek
Tables Module
Add column called Ha Get table
Convert cell area into hectares
Tables Module
Add co -Get tab
_ _ _ Convert
© 2002 Taylor & Francis
Trang 4WATERFOWL HABITAT ANALYSIS
You have grids of lakes One grid is from early summer and the other grid is from late summer You want to create a grid of the best lakes for waterfowl habitat lakes that had at least 1 hectare of exposed mudflats in late summer due to drawdown of the lake water level The cell size of each grid is 10 meters Fill in the following flowchart to solve your GIS problem.
EARLY 0= nonlake cells
1=Iakes in early summer
DRAWDOWN O=Not
1= Cells that are dry in late
1=lakes in late summer
GROUPS Groups of drawdown cells
BIG_AREAS Drawdown areas exceeding
1 hectare 1100 cells)
© 2002 Taylor & Francis
Trang 5GROUNDWATER APPLICATION
You have a grid of well locations, gas station locations, soils, and parcel ownership that contains the address of the owner of each parcel.
Outline what tools you would use to develop a text file of all well owners that have wells on sandy textured soils within a kilometer of a gas station.
SOILS
1=Sand
2= Loamy sand
8= Silty clay
9=Clay
STATIONS
O=Not gas station
1=Gas station cells
Text fileof
addresses of
well owners
within 1 km of a
gas station with
well on sandy
texture soils
SANDY O=Not sandy texture 1=Sandy textures
STATION_1KM O=Not near gas station 1=Within 1 km of gas station
WELLS O=Not a well cell 1=Well cells
CONTACTS Grid of owners with wells within 1 km of a gas station on sandy texture soils
SANDY_KM O=Not
1=Sandy texture and within 1 km of station
, SITES O=Not
1=Wells on sandy texture and within 1km of station
PARCELS Grid of parcel IDs and owner addresses
© 2002 Taylor & Francis
Trang 6MOOSE HABITAT ANALYSIS
You have grids of moose locations, random locations and vegetation types You want to estimate the mean distance of moose and random locations to the nearest willow cell All grid cells are 10 meters in size.
Fill in the following flowchart with the appropriate grid operations to solve your GIS problem:
VEG Vegetation type grid
WILLOW Willow grid
DIST_WILLOW Distance to nearest willow cell
MOOSE O=Not a moose cell
1=Moose location cell
MOOSE_DIST For each moose location, distance to nearest willow cell
MOOSE_DIST.TBL Table containing mean distance to nearest willow cell for moose locations
RANDOM O=Not a random location 1=Random location cells
RAND_DIST For each random location, distance to nearest willow cell
RAND_DIST.TBL Table containing mean distance to nearest willow cell for random locations
© 2002 Taylor & Francis