Coastal Hazard Line demarcation

& Integrated Coastal Zone Management

Based on established scientific principles

Demarcation of a VulnerabilitySetback / Hazard line.

Setback line is the boundary line beyond which the effect of Natural Hazards such as erosion and sea-level-rise will not be felt.

The parameters involved are: Elevation, sea-level-rise & Coastal Erosion.

Elevation: DEM will be generated by Photogrammetry.

Sea-Level Rise: Tidal data will be processed to compute the 100 year Return Period Extreme Tidal Height values at any Transect point using Weibull Distribution and Linear Interpolation.

Coastal Erosion: Annual Rate of Coastal Erosion will be Computed by comparing the oldest Topo-Map and the Latest Aerial Photography Ortho / satellite Image and extrapolated to next 100 years.

Fresh Aerial Photography” with 9 cm gsd using Digital Aerial Camera.

Primary Ground Control. Block Control Control extension -

Photogrammetry. AT & Block adjustment. DEM Collection at 5m Grid. Ortho & Feature Collection

Use extreme elevation data of 100 year return period at 20 major and 250 minor ports computed by G & RB, SOI.

Interpolate at other Transect points using linear interpolation.

Transfer these heights to the DEM and join the line.

This will give the flood line.

Compute rate of coastal erosion at every 500 m transect point using old Topo Sheet and new satellite image / ortho photo data.

Extrapolate for 100 year return interval using linear extrapolation.

This line represents coastal erosion line.

The final Hazard Line Is the most landward of the Flood Line & Erosion Line.

Delineate the same In a GIS Environment.

Mark on Ground with pillars / markers.

EROSION LINE

Max Flood line

SEA AREA

Land

HAZARD LINE

Coastal States

a)LevellingEstablish BMs & BCP (heights)

b)Establishment of Primary GCPsc)Establishment of Secondary GCP and BCP

(Horizontzl)d)Aerial Photography

QA/QC proceduresPhotographyStatutory clearances

e)Photogrammetry and Map Data generation Aerial Triangulation (AT) Digital Elevation Model (DEM) and

Contour generation Ortho-rectification

f) Tidal Data Analysis Computation of 100 year Return

Period Flood Line.

g)Erosion Data Analysis Computation of 100 year Return

Period Erosion Line.

g)Mapping the final Hazard Line Most Landward of Flood Line /

Erosion Line.

h)Demarcation of Hazard Line Fixing of Markers/ Pillars

Aerial Photography & Preliminary AT/DEM/Ortho.

Rigorous Photogrammetric Survey.

Quality Control at various stages.

Provision of Ground Control Points

BySurvey of India

Primary Control

Secondary Control

High Precision

Double Tertiary

Single Tertiary

Stability Check

Linear Adjustment

Along The Flight Line

Post pointing of Staff Positions to serve as

Check Points.

DT LevellingDT LevellingNo of LinesNo of Lines 22   Length Length 1860018600 KmKm

ST LevelingST LevelingNo of Lines (No. No of Lines (No. of Strips +1)of Strips +1) 99   Length (6 Lines)Length (6 Lines) 8370083700 KmKmTotal Length of Total Length of Level LinesLevel Lines 102300102300 kmkm

Principle of Whole To Part

Leap Frog Method

Least Square Adjustment Carrier Phase

Relative Positioning (Phase Difference)

Static Mode

Loop Closure

Positional Accuracy 2 Cm

GPS

Radial Line Method

Loop Closure Check

Positional Accuracy 4

Cm

Planning

Adjustment

DEM

No. of Mass Points 1,736,000,000

Break lines 50%

Total Height Total Height PointsPoints 2,604,000,0002,604,000,000

Density of Mass Point@ 5 m

Omission of Break lines

Checking of TIN

Most vital component of this Project.

Photography is just a means to the end.

Its specifications have been designed to meet the end-product

gsd 9 cmDesigned to maximize its utility in Photogrammetric Processes

Acquisition RequirementsPlatformCamera

MountsCertification

Flight Plan and Coverage ( http://www.moef.nic.in)Flying Conditions

Image RequirementsSpatial ResolutionSpectral ResolutionRadiometric Resolution

Control RequirementsPre-pointed ControlDifferential GPS/GNSS & IMU ControlGround Stations

GPS Control for horizontal control (1st Order)Levelling Heights for vertical control (H.P BMs)

Quality Control

Closely Managed Processes with built-in Closely Managed Processes with built-in Quality ChecksQuality Checks

DocumentationDocumentation Standard Operation ProceduresStandard Operation Procedures Work FlowsWork Flows

Quality Checks at each stageQuality Checks at each stage GCP Control (Plan & Height) – Rigorous Deptt. GCP Control (Plan & Height) – Rigorous Deptt.

standardsstandards Flight Planning - ApprovalFlight Planning - Approval Flight Execution & Monitoring (Differential GPS and Flight Execution & Monitoring (Differential GPS and

IMU)IMU) Flight Evaluation – Corrective action while Flight Evaluation – Corrective action while

resources still at siteresources still at site Go ahead approval.Go ahead approval.

Quality Control RecordsQuality Control Records

Preliminary AT/Ortho-Preliminary AT/Ortho-rectification rectification (FULL PROOF QA/QC )with (FULL PROOF QA/QC )with minimum effort and gestation lag)minimum effort and gestation lag) Suitability for Photogrammetric Suitability for Photogrammetric

Processes,Processes, check for Direct Sensor check for Direct Sensor

Orientation, Orientation, Pre-pointed controls, Pre-pointed controls, overlaps & gaps overlaps & gaps

Measurement and certification Measurement and certification of work also based on of work also based on Preliminary OrthoPreliminary Ortho

Sea Level Rise / Flood Line Mapping

Flood Line MappingInput

100 year return period elevations of 20 primary ports.

Data of about 250 secondary ports.

0.5m contours / DEM. Ortho aerial image.

Interpolation Of Return Period Tidal Elevations

Compute 100 year Return Period Max Compute 100 year Return Period Max Elevations values at each of the 20 primary Elevations values at each of the 20 primary ports.ports.

Compute 100 year Return Period values at Compute 100 year Return Period values at each of the 250 Secondary Port using 2 each of the 250 Secondary Port using 2 neighboring primary portsneighboring primary ports

This will give 100 year RPs at about every 30 This will give 100 year RPs at about every 30 km.km.

Draw a base line for measurements and make Draw a base line for measurements and make

Transects at every 500 m.Transects at every 500 m.

Linearly Interpolate at Transect points using 2 Linearly Interpolate at Transect points using 2 neighboring Primary / Secondary ports.neighboring Primary / Secondary ports.

Interpolation Of Return Period

Primary Ports

Secondary Ports

Transect Points

Survey of India is one of the premier organizations in the world having more than 130 years of expertise in tidal data acquisition.

It is a large store house of tidal data , collected

from major part of its area of responsibility.

Presently Survey of India is maintaining a huge network of permanent tidal stations , located along the Indian Coast and Islands.

These tidal stations are equipped with state-of-the-art digital tide gauges , co-located with dual frequency GPS receivers and real time data transmission facilities through dedicated VSAT network.

Estimated tidal heights for 100 years return period have been determined for the ports having tidal records for at least 10 years. 20 such tidal stations have been identified in the east and west coast for determining the tidal level for 100 years return period.

i. Provide minimum 10 years of historical tide gauge data for all ports within the state boundary for which long term observations are available.

ii. Determine the Annual Maximum Water Level for each year and each port.

iii. Reduce Annual Maxima from Chart Datum to IMSL and tabulate.

iv. Rank order the datav. Calculate Weibull distribution and plotting positions of

all the available data.vi. Fit regression line to plotted data and extrapolate to

100 years.vii. Calculate the tidal heights for 100 years return period.

Interpolation Of Return Period At Minor Ports 100 years Return Period for major port M1 (Known Station) = 5.89 m 100 years Return Period for major port M2 (known Station) = 4.80 m

Distance between M1 & M2 = 47.52 km Distance between M1 and Secondary port S = 21.46 km

Indirect Interpolation: Tidal Ht. for 100 year RP-HAT of M1 =5.8900-4.5051 = 1.3849 Tidal Ht. for 100 year RP-HAT of M2 =4.8000-4.0379 =

0.7621

Correction for S = 1.3849+{(0.7621-1.3849)*Distance from M1 (21.46)}/Total Distance(47.52)

=1.1036 m100 years Return Period for S = HAT of S + Correction =

4.2351+1.1036 = 5.3387 m

100 years Return Period Calculated by Indirect interpolation = 5.3387 m5.3387 m

5.89 m

4.80m

47.52 km

HAT = 4.5051 m

HAT = 4.0379 m

RP - HAT = 1.3849 m

RP - HAT = 0.7621 M

DIFFERENCE IN RP-HAT = 0.6228 m

Completeness of Tidal Data Completeness of Tidal Data ….. …..

• All available Data up to 2010 will be used All available Data up to 2010 will be used after checking for quality.after checking for quality.

• Month-wise distribution / availability of data Month-wise distribution / availability of data will be checked.will be checked.

• Regularity of Missing Data will also be Regularity of Missing Data will also be checked.checked.

• Tsunami / Cyclone data will also be Tsunami / Cyclone data will also be included.included.

INDIAN MEAN SEA LEVEL (IMSL)

HEIGHT OF TIDE ABOVE CD

HEIGHT OF TIDE ABOVE IMSL

CHART DATUM (CD)

Converting Chart Datum IMSL

Linear Interpolation at Transect Linear Interpolation at Transect PointsPoints

Two ports ( primary / secondary) will be taken

at a time: (x,y) (x,y) (x2,y2)(x2,y2)

(y - y1) (y - y1) ΔΔy y ( x1,y1) (x- ( x1,y1) (x-x1) x1) ΔΔx x

(y - y1) / (x-x1) = ((y - y1) / (x-x1) = (ΔΔy/y/ Δ Δx)x)

Based on Equation of line or SimilarTriangles y = y1 + (y = y1 + (ΔΔy/y/ Δ Δx)(x-x1)x)(x-x1)

Erosion Line Mapping.

Required inputs:Required inputs:- Multiple shoreline positions- Multiple shoreline positions- User-generated baseline- User-generated baseline

Transects For Erosion Line Mapping.

DSAS generates transects that are cast perpendicular DSAS generates transects that are cast perpendicular to the baseline at a user-specified spacing alongshore.to the baseline at a user-specified spacing alongshore.

The transect/shoreline intersections along this baseline The transect/shoreline intersections along this baseline are then used to calculate the rate-of-change statistics.are then used to calculate the rate-of-change statistics.

Project DeliverablesProject Deliverables

DEM: DEM: GridGrid 5 m5 m

Ortho-Rectified Photographs Ortho-Rectified Photographs  1:100001:10000 ScaleScale

Hazard Line Marked on the Ortho-Rectified PrintsHazard Line Marked on the Ortho-Rectified Prints

Hazard Line demarcated on the groundHazard Line demarcated on the ground

Symbolized Vector Data:Symbolized Vector Data:

  Features:Features:

  Village Boundary Polygon with NameVillage Boundary Polygon with Name

  Village Roads and aboveVillage Roads and above

  All NamesAll Names

  Other Major Feature such as Other Major Feature such as

 Rivers, Lakes, Sea, Railway lines, Canals Rivers, Lakes, Sea, Railway lines, Canals etcetc