Introduction to GIS Modeling

Week 6 — GIS Modeling Procedures GEOG 3110 –University of Denver

Presented by

Joseph K. Berry

W. M. Keck Scholar, Department of Geography, University of Denver

Anatomy of a GIS Model (landslide susceptibility); Example GIS Model

(electric transmission line routing)

; Mini-Project discussion; other GIS Model Examples as time allows

(land planning, wildfire risk, pipeline routing and retail competition analysis)

Online Exam 1

(Midterm)

This exam is a 2.0 hour , closed book affair taken over the Internet (honor system) — you can take during any 2-hour block after 8:00 am Friday February 12 and must be completed by 5:00 pm Wednesday February 17 (submit via email to [email protected]) You will download the exam from the class website (time/date stamped) and email the completed document to me within 2.0 hours Note– Tutor25.rgs

, Agdata.rgs

, Island.rgs, Bighorn.rgs, GosseEgg.rgs

and Smallville.rgs

databases are accessed from MapCalc Have a hand calculator or use Window’s Calculator… Start



Accessories Programs

 

Calculator Note that there will be two parts to the exam — answer FIVE questions for Part 1, ONE from Part 2 and ONE from Part 3 Part 1 100 Points Terminology/concepts: Choose any 5 of the seven 20-point questions (i.e., do not answer two) Part 2 50 Points How things work: Choose 1 of the three 25 point questions… Mini-exercises: Choose 1 of the three 25 point questions (Berry)

Class Logistics and Schedule

Midterm Study Questions (hopefully you are participating in a study group) Midterm Exam … you will download and take the 2-hour exam online (honor system) sometime between 8:00 am Friday February 13 and must be completed by 5:00 pm Wednesday February 17 Blue Light Special …20 minutes of Instructor “Help” on midterm study question “toughies “ Exercise #6 ( mini-project ) — you will form your own teams (1 to 3 members) and tackle one of five projects; we will discuss the project “opportunities” in great detail later in class …assigned tonight Thursday, February 12 and final report due Sunday, February 21 by 5:00pm What should we do about submitting “large” mini-Project Reports …???

No Exercise Week 7 — a moment for “dance of celebration” Exercises #7 and #8 — to tailor your work to your interests, you can choose to not complete either or both of these standard exercises; in lieu of an exercise, however, you must submit a short paper (4-8 pages) on a GIS modeling topic of your own choosing.

Final Exam — to lighten the load at the end of the term, you can choose to forego the final exam; you will receive your average grade for all work to date.

Berry

GIS Modeling

(Binary Logic; Ranking Model)

0, 1 0, 1 0, 1 0, 1

Binary Choropleth (Berry)

GIS Modeling

(Arithmetic Average; Rating Model refinement)

1 - 9 1 - 9 1 - 9 1 - 9

Ratio Choropleth (Berry)

GIS Modeling

(Simple Buffer Extension)

0, 1

(Berry)

GIS Modeling

(Effective Buffer Extension)

0, 1 0 - 1

…but what about a refinement that would create a weighted buffer with declining weight factors for increasing distance —

0 = outside buffer 1 = road cell .9 = close to road : = increasing distance .1 = buffer edge cell

(Berry)

Transmission Line Routing Model

(Hypothetical)

Existing Powerline

Goal

– identify the

best route for an electric transmission line

that considers various criteria for minimizing adverse impacts.

Proposed Substation Houses

Criteria

– the transmission line route should…



Avoid areas of

high housing density

…prefer low housing density



Avoid areas that are …prefer close to roads

far from roads



Avoid areas

within or near sensitive areas

…prefer far from sensitive areas



Avoid areas of high

visual exposure to houses

…prefer low visual exposure

Sensitive Areas Roads Elevation

( See Beyond Mapping III , Topic 19 for more information)

Houses

(Berry)

Routing and Optimal Paths

(avoid high housing density)

PROPOSED SUBSTATION (END)

AVOID AREAS OF HIGH HOUSING DENSITY

EXISTING POWERLINE (START)

Least preferred (high cost) Most preferred (low cost)

HOUSES HOUSING DENSITY DISCRETE PREFERENCE MAP

Step 1.

Housing Density levels (0-83 houses) are translated into values indicating relative preference (1= most preferred to 9=least preferred) for siting a transmission line at every location in the project area. Single-criteria Model

MOST PREFERRED ROUTE ACCUMULATED PREFERENCE SURFACE

Step 2.

Accumulated Preference from the existing powerline to all other locations is generated based on the Discrete Preference map.

Step 3.

The steepest downhill path from the Substation over the Accumulated Preference surface identifies the “most preferred route”—

Most Preferred Route avoiding areas of high visual exposure

(Berry)

Routing Model Flowchart

(Model Logic)

Model logic is captured in a flowchart where the boxes represent maps and lines identify processing steps leading to a spatial solution

Avoid areas of…

Within

a single map layer

Among

a set of map layers “Algorithm” “Calibrate” “Weight” High Housing Density …build on this single factor Far from Roads In or Near Sensitive Areas High Visual Exposure Multi-criteria Model (Berry)

Routing Model Flowchart

(Model Logic)

Model logic is captured in a flowchart where the boxes represent maps and lines identify processing steps leading to a spatial solution

Within

a single map layer

Among

a set of map layers “Algorithm” “Calibrate” “Weight” Step 1 Identify overall Discrete Preference (1 Good to 9 Bad rating)

End Start Start Best Route End

Step 2 Generate an Accumulated Preference surface from the starting location to everywhere

Step 1 Step 2

Accumulation Surface

Step 3

Route Step 3 Identify the Most Preferred Route from the end location (Berry)

Step 1

Discrete Preference Map

Calibrate

…then

Weight HDensity RProximity

Discrete Preference Map Most Preferred

“Pass” SAreas VExposure …identifies the “ relative preference ” of locating a route at any location throughout a project area considering all four criteria [avoid areas of High Housing Density, Far from Roads, In/Near Sensitive Areas and High Visual Exposure]

Least Preferred “Mountain” of impedance (avoid) Most Preferred (Berry)

Step 2

Accumulated Preference Map

(digital slide show AccumSurface )

…identifies the “ total incurred preference ” (minimal avoidance) to locate the preferred route from a Starting location to everywhere in the project area

Accumulated Preference Map (most preferred)

“Pass”

(most preferred)

“Pass”

Splash Algorithm – like tossing a stick into a pond with waves emanating out and accumulating preference as the wave front moves (Berry)

Optimal Route (most preferred)

“Pass”

Step 3

Most Preferred Route

(digital video OptimalPath )

…the steepest downhill path from the End over the accumulated preference surface identifies the optimal route that minimizes traversing areas to avoid (most suitable)

(most preferred)

“Pass”

Note: Straightening and Centering techniques can be applied …see Beyond Mapping III , Topic 19 for more information (Berry)

Step 4

Generating Optimal Path Corridors

(digital slide show TotalAccumulation.ppt

)

…the accumulation surfaces from the Start to the End locations are added together to create a total accumulation surface —the “valley” is flooded to identify the set of nearly optimal routes

(most preferred)

“Pass” Optimal Corridor

(most preferred)

“Pass”

(Berry)

Model Results

(Georgia Experience ...EPRI, GTC, Photo Science ) Combining alternative corridors identifies the decision space reflecting various perspectives

Feature Article in GeoWorld, April, 2004 A Consensus Method Finds Preferred Routing

See www.geoplace.com/gw/2004/0404/0404pwr.asp

(Berry)

Engineering 5 times more important

Engineering

Routing Model Flowchart

Siting Model

Route Weight

Natural 5 times more important

Natural Environment

Built 5 times more important

Built Environment

Simple Average Equally important

…maps identifying areas that must be avoided

Avoidance Areas

Linear Infrastructure Slope

Calibrate

Public Lands Streams/ Wetlands Floodplain Land Cover Wildlife Habitat Building Density Proximity to Buildings Spannable Lakes/Ponds Proposed Dev.s

Land Use

…maps of the criteria for siting are identified, then interpreted by different stakeholder groups for relative importance in routing

Non Spannable Water bodies Mines and Quarries (actvie) Buildings Airports Military Facilities EPA Superfund Sites State and National Parks USFS Wilderness Area Wild/Scenic Rivers Wildlife Refug e Listed Archeology Sites Listed NRHP Districts And Buildings City and County Parks Day Care Centers Cemetery Parcels School Parcels (K-12) Church Parcels

(Berry)

Alternate Corridors

…Alternate Corridors for each stakeholder perspective are generated

Built Natural Engineering Simple (Average) All

(Berry)

Additional Data Collection

…extensive site-specific information is gathered within the Alternative Corridor boundaries to aid in refining and selecting final options (Berry)

Generate Alternative Routes

(Design Team) …Design Team finalizes the Alternate Routes

Routes are defined

within the Alternative Corridors

using expert judgment .

    

Objective Quantitative Predictable Consistent Defensible Exceptions are noted for deviations from optimal paths within the corridor area… Built Natural Engineering Simple …deviations outside the corridor area require variance approval

(Berry)

Routing Model Experience

(Conclusions)

The Methodology is…

Objective, Quantitative, Predictable, Consistent, Defensible GIS-based approaches for routing electric transmission lines utilize

relative ratings ( calibration)

and

relative importance (weights)

in considering factors affecting potential routes. A quantitative process for establishing

objective and consistent weights

is critical in developing a robust and defendable transmission line siting methodology. Note: there are advance techniques for Calibration and Weighting …link to CalibrateWeight.ppt

See www.innovativegis.com/basis/present/GW04_routing/GW_Apr04_routingPowerline.htm

Feature Article in GeoWorld, April, 2004 “A Consensus Method Finds Preferred Routing” (Georgia Experience)

See www.innovativegis.com/basis , select , online book Beyond Mapping III, Topic 19 “ Routing and Optimal Paths ” See www.innovativegis.com/basis , select Column Supplements

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Beyond Mapping , September 03, Delphi (Calibration) See www.innovativegis.com/basis , select Column Supplements

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Beyond Mapping , September 03, AHP (Weighting) (Berry)

Mini-Project

(Exercise #6)

Exercise #6 (mini-project)

—

you will form your own teams (1 to 3 members) and tackle one of eight projects

…assigned today and final report due Sunday, February 21 by 5:00pm Project 1 – Hugag Habitat Suitability Revisited Project 2 – Visual Exposure to Timber Harvesting Project 3 – Emergency Response Project 4 – Geo-Business Analysis Project 5 – Landslide Susceptibility Project 6 – Transmission Line Routing Project 7 – Wildfire Risk Analysis Project 8 – Pipeline Spill Migration Project 9 – Biomass Accessibility (Berry)

GIS Modeling

(Example Project) Example Project –

Slippery Mountain Landfill Suitability

…criteria for a 0 (not suitable), 1 (minimally suitable) through 9 (extremely suitable) …Your charge is to prepare a prospectus for deriving the Landfill Suitability map that clearly explains how each of criteria are evaluated and then combined into an overall suitability map that respects the legal constraints and reflects the county commissioners’ criteria weightings. In addition, calculate the average landfill suitability rating for each district (Districts map). Finally, generate a map that identifies the average rating within 300 meters (3-cell reach) for each of the housing locations (Housing map). (Berry)

Example Graded Project –

Landfill Suitability

…posted online at class website, under “Lecture Notes” section, Week 6, Graded Mini-Project Example (Berry)

Project 1 –

Hugag Habitat Suitability Revisited

Hugags like to be near water Hugags are terrified of roads Hugags like cover diversity Hugags like to be near forest edges …add four new habitat criteria …implement a weighted average analysis and compare the old and new results (Berry)

Project 2 –

Visual Exposure to Timber Harvesting

(Berry)

Project 3 –

Emergency Response

…first phase off-road travel by ATV starting at any road location and encountering the following ATV_friction for determining effective proximity …second phase proceeds on foot into the ATV inaccessible areas by using the “Explicitly” option to Spread …final map uniquely identifies ocean (blue) and hiking inaccessible areas (grey), and rescue response time (green to red) as both a 2-D map and a 3-D drape on the elevation surface (Berry)

Project 4 –

Geo-Business Analysis

Competition Analysis

Part 1— calculate two

travel-time maps , one from Kent’s Emporium and the other from Colossal Mart

Part 2— create a relative

travel-time advantage map clearly shows which store has the relative advantage

Part 3— generate a binary map identifying just the

“combat” zone where neither store has a strong advantage

Part 4— generate a map that identifies the

customers in the combat zone .

Density Analysis

Part 1— Create a

customer density surface that identifies the total number of customers within half a kilometer

Part 2— Generate a binary map identifying the

“pockets” of unusually high customer density (mean + 1 Stdev or more customers per 500m reach).

Part 3— Generate a map that shows the relative

travel time advantage within the pockets of unusually high customer density.

(Berry)

Project 5 –

Landslide Susceptibility

…criteria for a 0 (not susceptible), 1 (minimally susceptible) through 9 (extremely susceptible) Overall landslide susceptibility is defined as the weighted average rating of the three criteria A second map that identifies the susceptibility ratings for just the uphill areas around roads 250 meters (2.5 cells) to Another map identifying the average landslide susceptibility (1 to 9) within the uphill buffered area around roads for each of the management districts identified on the Districts map (Berry)

Project 6 –

Transmission Line Routing

Least Cost Path Accumulated Cost Map Discrete Cost Map The client, MegaWatt Power, needs to identify three routes—



a route that treats visual exposure from houses and roads equally (simple average Cost),



a route considering visual exposure to houses ten times more important than exposure to roads, and



a route considering visual exposure to roads ten times more important than exposure to houses. (Berry)

Project 7 –

Wildfire Risk Analysis

Wildfire Risk is related to— cover type , terrain and human activity factors Wildfire risk needs be summarized in a couple ways… Calculate the average wildfire risk for each of the districts.

Create a map that shows the average wildfire risk within a 300 meter buffer around all housing locations. …implement the “common sense” idea that locations closer to the fire station at the Ranch community center (Locations base map) ought to have the calculated risk lowered. (Berry)

Project 8 –

Pipeline Spill Migration

Pipeline Spill is related to— physics , product properties and terrain conditions



Identify the implied steepest downhill spill path for each of the three test locations (Spills map) along the proposed new transmission pipeline and map as a 3D Grid display with all three route individually identified and draped over the Elevation surface.



Identify the minimum path time for a spill anywhere along the entire Proposed route (Pipelines map) and map as a 3D Grid display with the spill density map (10 Equal Ranges contours) draped over the Elevation surface.



Create a map that shows the estimated minimum time for a spill based on the spill time map (created above) to reach all of the impacted areas with the high population HCA (HCA_Hpopulation map).



To illustrate the model’s sensitivity to different products create another minimum time map for the high population HCA that considers crude oil flow instead of water. (Berry)

Project 9 –

Biomass Accessibility

… “scoping” meeting scheduled for tomorrow, Friday, February 12, 12-4 pm

Roads Forests Resource Access

.

The areas of Pine Beetle remediation are first identified by the level of severity and then characterized by the relative access (effective proximity) considering the intervening conditions and characteristics between the roads and the resource areas identified for remediation.

Intervening Considerations Resource Access

Intervening Considerations

.

Terrain steepness, variable-width stream buffers and housing density serve as factors determining a location’s relative suitability for biomass removal, as well as affecting a location’s relative accessibility from the roads.

Slope Water Houses

(Berry)

GIS Modeling

(Mini-Projects)

…Good luck!!!

There is a “ Life-Line ” if you get totally stuck. For the price of one grade (drop from 100% possible to 89% possible) I will email you a MapCalc script with the complete solution—you just need to write-up the solution in a “ professional, free of grammatical/spelling errors, well-organized, clearly written, succinct manner ” that demonstrates your understanding of the processing. General clarification, questions and Life-line requests will be processed via email workdays 8:00-4:00 pm and Saturday/Sunday, 9:00-11:00 am . It behooves you to decide on a project and outline a solution as soon as possible. Note: emergency situations call me at 970-215-0825 (Berry)