Ice Road Routing: A Complex Problem

North Slope Decision Support System: Ice Road Planning Algorithms

3rd Stakeholder WorkshopApril 27-28, 2011

Ice Road Routing: A Complex ProblemOften multiple exploration sites

Sometimes multiple possible starting points

Avoidance of undesirable/difficult features

Water availability

Regulatory issues

Path re-use in future seasons

Multiple objectivesCostTimeRisk/Reliability

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Ant Colony SystemsBased on natural behavior of ants in route finding

between nest and food… Pheromones!

Algorithm Development

Ant Colony SystemsBased on natural behavior of ants in route finding

between nest and food… Pheromones!

Algorithm Development

Ant Colony SystemsBased on natural behavior of ants in route finding

between nest and food… Pheromones!

Algorithm Development

Ant Colony SystemsBased on natural behavior of ants in route finding

between nest and food… Pheromones!

Algorithm Development

Issues to Solve• Ants get lost in complex and open topologies

• Most traditional ACS applications are single objective

• Our real-world ants have to build their own roads and need water

Graph Pruning• Keep ants from getting lost by reducing topology

to non-redundant paths

0 100 200 300 400 500 600 700 800 900

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200

300

400

500

600

Graph Pruning• Keep ants from getting lost by reducing topology

to non-redundant paths

0 100 200 300 400 500 600 700 800 900

100

200

300

400

500

600

Traditional ACS includes link choice heurisiticsExploration versus Exploitation

Probabilistic Choice weighted by pheromones and a priori suitability scores

Multi-Objective Path-Finding

Pher1 Suit1

Pher2 Suit2 Pher3

Suit3

Multi-objective ACS includes multiple suitability scores, preference functions, and non-dominated sorting to find pareto-fronts

Multi-Objective Path-Finding

Pher1 SuitA1 SuitB1

SuitC1

Pher2 SuitA2 SuitB2

SuitC2Pher3 SuitA3 SuitB3

SuitC3

Obj A

Obj

B

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11

33

As the ants move along the path, they search for the nearest available permitted lake to withdraw water from.

Water Accounting

4

On large open grids, sometimes the paths will have unnecessary bends or curves.

Path Straightening

The ants can determine the best starting point given a stretch of road.

Multiple Start Points

Steiner Problem – Minimum Spanning Tree

Multiple End Points

Waypoint

Steiner Problem – Minimum Spanning Tree

Multiple End Points

When there are more than 3 endpoints then pheromone sharing is used.

Multiple End Points

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Route Travel Time (hrs)

Construction Cost ($)

New Permits Needed

Orange 0.25 1,400,000 2

Green 0.4 1,000,000 1

Blue 0.45 1,200,000 0

The resolution of the roads are limited by the 100m x 100m DEM data used.

Water accounting for road construction is dependent upon available lake data. Some data may not be available.

Limitations

Demonstration

1. Review “Permitting Matrix”

2. Let’s sketch out planning process and identify tasks that NSDSS can help improve

How does NSDSS fit into the planning process?

“Permitting Matrix”O&G Exploration Permitting

AgencyNPRA

State-owned Land

Private Land ANWR

Permit Required Activity* Permit Required Activity* Permit Required Activity* Permit Required Activity* Permit Required Activity*FederalPermit to Drill BLM x Closed to Exploration x x x x xRight of Way BLM x Closed to Exploration x x x x xSurface Use BLM x Closed to Exploration x x x x xWaste Plan BLM x Closed to Exploration x x x x xHazardous Materical Emergency C-Plan BLM x Closed to Exploration x x x x xRight of Entry for Survey and Exploration BLM x Closed to Exploration x x x x xSubsistence Plan of Cooperation BLM x Closed to Exploration x x x x xLetter of Authorization for Incidental Take of Polar Bear USFWS x x x Closed to Exploration x x x A, BSection 7 Consultation USFWS x x x Closed to Exploration x x x x xRequest for Special Use Permit USFWS x x x Closed to Exploration x x xNational Pollutant Discharge Elimination System General Permit for drilling camp EPA x x x Closed to Exploration x x x x xSpill Prevention Control and Countermeasure Plan (Staging Area and Drill Site) EPA x x x Closed to Exploration x x x x x

StateLease/Unit Plan of Operations ADNR x Closed to Exploration x x x x xTemporary Water Use Permits ADNR x x x Closed to Exploration x x x x xLand Use Permit ADNR x x x Closed to Exploration x x x x xState Historic Preservation Office (depends on if includes historically significant sites) ADNR x x x Closed to Exploration x x x x xAlaska Coast Management Consistency Review ADNR x x x Closed to Exploration x xAir Quality Minor General Permit 1 (MGP1) ADEC x x x Closed to Exploration x x x x xAuthorization for Temporary Storage of Drilling Waste ADEC x x x Closed to Exploration x x x x xOil Discharge Prevention and Contingency Plan Amendment ADEC x x x Closed to Exploration x x x x xCertificate of Financial Responsibility ADEC x x x Closed to Exploration x x x x xFish Habitat (if sensitive fish in lake) ADFG x x x Closed to Exploration x x x x xPermit to Drill (if drilling planned) AOGCC x x x Closed to Exploration x x x x xWell Sundries (if drilling planned) AOGCC x x x Closed to Exploration x x x x x

LocalDevelopment Permit NSB x x x Closed to Exploration x x x x xAdministrative Approval NSB x x x Closed to Exploration x x x x x

*Required Activities to receive permit/letter of authorization

A Den Detection SurveyB Ongoing monitoring for polar bear dens

Jursidiction Proximity to CoastWithin 1 Mi.

of Bear HabitatWithin 1Mi

of CoastWithin ADNR Coastal

Zone BufferWithin 25Mi

of CoastOutside of

25 mi. buffer

Planning Process