lesson5 gis1

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Geographic Information Systems

A geographic information system is a system for management,

analysis, and display of geographic knowledge, which is represented

using a series of information sets such as maps and globes,

geographic data sets, processing and work flow models, datamodels, and metadata.



GIS engages students and

promotes critical thinking,

integrated learning andanalysis, and multiple

intelligences and sciences.



IntroductionGeographic Information System (GIS) is a computer basedinformation system used to digitally represent and analyse thegeographic features present on the Earth' surface and the events(non-spatial attributes linked to the geography under study) that

taking place on it. The meaning to represent digitally is to convertanalog (smooth line) into a digital form.

"Every object present on the Earth can be geo-referenced", is thefundamental key of associating any database to GIS. Here, term'database' is a collection of information about things and theirrelationship to each other, and 'geo-referencing' refers to thelocation of a layer or coverage in space defined by the co-ordinatereferencing system.



GIS-controlled

workflow



Case studyDecision-support system yields

better pipeline route



G l d



Goals and

objectivesIdentifies constraints

Avoid undesirable areasDefine divert

Economic feasibility



GoalsCross-country petroleum pipeline route selection isgoverned by the following goals:

•

Establish the shortest possible route to connect originating,intermediate, and terminal locations.

• Ensure, as far as practicable, accessibility during operationand maintenance.

• Preserve ecological balance and avoid or minimizeenvironmental damage.

• Avoid populated areas.

• Keep rail, road, river, and canal crossings to a minimum.

• Avoid hilly or rocky terrain.

• Avoid a route parallel to high-voltage transmission lines orDC circuits.

• Use existing right-of-way, if possible.

• Avoid such other obstacles as wells, houses, orchards,

lakes, or ponds.



Mistakes

• 12 inch, 102 km pipeline losses 120 millonrupees/year against 100 million forrerouting and having one more pump

station

• 1000 million rupees risk for belt areaagainst 60 million rupees



ProblemConflict between all

these factors

SolutionAnalytical hierarchy

process AHP

A l ti l hi h



Analytical hierarchy processAHP

The following methodology has been adopted inselecting optimal pipeline routes.

• Identification of alternative routes.

• Preparation of strong database for each route.

• Identification of the factors and subfactors leading topipeline route selection.

• Formulation of risk structure in line with AHPrequirements.

• Pair-wise comparison of factors and subfactors todetermine the importance of factors and subfactors in

selecting the route.• A Pair-wise comparison of alternatives, with respect

to each sub-factor, to determine the benefits of oneroute over another.

• Synthesizing the results across the hierarchy todetermine the optimal route.



Focus

Elements affectingdecision

Decision options and comparison

matrices

Subjectivity

Experience

knowledge

Prioritize

Weights

and

relative

weights



Data Processing

slopetopogridsoildrainsrailwaysRoadsutilitiespopulationAirports

reclassreclassreclassreclassreclassreclassreclassreclassreclass

Population civilization Land cover topography

Final layer

50%

30%20%10%

50% 30% 50% 20% 50% 50% 50% 50%

40%



vandalism

• willful or malicious destruction or defacement of public or private property

• 1 : obstinately and often perversely self-willed

• 2 : done deliberately : INTENTIONAL

• intent to commit an unlawful act or cause harm without legal justification or excuse

• to mar the external appearance of : injure by effacing significant details <deface an inscription>

• archaic a : to inflict serious bodily harm on b : DESTROY

• synonym see INJURE

spoil



Concl sions



Conclusions• Route selection should be based on a detailed study of

alternatives that considers all factors. The selection model

presented here has the following advantages:• It allows the incorporation of interactive input by executives

from related functional areas.

• It helps make objective decisions.

• It incorporates both tangible and intangible elements via theAHP hierarchies. Qualitative and subjective judgments, as wellas quantitative data can be included in the priority-settingprocess.

• AHP is effective for conducting group sessions analytically and

systematically. There are multiple ways of including thesubjective judgments of many persons.

• The model allows the collection of more information about thedetailed engineering stage.

• Sensitivity analysis provides decision-makers with aknowledge of the effects of their decisions.



California line beats

odds, begins movingviscous crude oil

130000bpd



130000bpd

130 miles

20 inch

Temp ambient

to 180 degF

Pressure 50 -

1460 psiEIS

environmental

impact

statement

EIR report

3000 pages

13 API

17750cst

@60f

1300@100f



The challenges were met with thefollowing innovations

• Horizontal directional drilling of 10 crossings totaling more than 5 miles under activelandslides, high scour rivers, and some of the busiest highways in the US.

• Thirty three nitrogen-actuated block valve sites (aboveground and buried) foremergency isolation of the system.

• High-speed, fiberoptic communication and control system.• Advanced supervisory control and data acquisition (SCADA) system with integrated

leak detection and dynamic on-line training simulation.

• Variable-frequency drive for efficient pump operations.• High-efficiency electrical pump motors and substation equipment.• Fully functioning backup control center.• Multichannel, peer-to-peer, Ethernet-based communications between facility

programmable logic controllers (PLC)s.• Sump tanks with secondary containment and continuous leak monitoring.• Advanced automation-sequence programming and control algorithms.• Geographic information systems (GIS) mapping and global positioning system (GPS)

data collection.



• Completion of the pipeline system required clearing numerous permitting,design, and safety hurdles. Some of the more challenging were:

• Intense permitting and agency oversight during design and construction.• Joint federal and state environmental review producing an exhaustive

environmental impact statement (EIS) and environmental impact report(EIR).

•

Difficult alignment consisting of a mix of agricultural lands, ruggedmountains, and very dense urban and industrial areas. The pipelinetraverses the heart of Los Angeles.

• Extraordinary system safety design, including leak-detection capabilitieshigher than industry norm.

• Detailed hazardous operations analyses.• Seismic design to mitigate the risk of crossing more than eight major faults,

including the San Andreas Fault.• Stresses from expansion-contraction of thermal cycles caused by a wide

operating temperature range.



4080 ft height

900 ft in .5 miles

decent more than

50% slope



A pipeline 324 mms outside diameter and 160 kilometers long transports crude oil 10 c.st. kinematicviscosity, 0.86 specific gravity and 0.5 kg/cm2 vapor pressure. The pipeline has the followingprofile:X 0 10 20 30 40 50 60 70 80 90H 50 120 200 250 320 400 250 200 180 210

X 100 110 120 130 140 150 160H 270 325 375 425 450 350 100Where:X = Distance from the first terminal, kms.H = Elevation, Meters.

The pipeline is operated by two pumping stations : one at the first terminal and the second at 70 kmsfrom the first terminal. Each pumping station consists of two identical centrifugal pumping unitsoperating in series. Each pump has the following characteristics:Q 0 100 200 300 400 500 600 700H 525 520 510 495 475 450 420 385EFF 0 36 60 74 80 78 70 58Where:Q = Discharge, M3/hr.H = Head, Meters.

EFF = Efficiency, %Find the expected throughput of the line at a utilization factor 91.3% and the absorbed horse-power ateach station.If the capacity has to be increased by 20% by looping the pipeline sections, find the length of loops,the percentage increase in the absorbed horse-power at each station and the safe thickness of thepipeline sections.Consider the pipe roughness 0.06 mms, the acoustic velocity in the crude 1150 m/sec. and the yieldstrength of the pipe material 42 kg/mm2.

lesson5 gis1

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