Flood Mapping Michael Durnin October 9 th

Transcription

1 Michael Durnin October 9 th 2014

2 Leading Surveyors Company Profile Est Celebrating 30 Years in Business Six Offices in UK & Ireland Over 30 Specialised Survey Services ISO 9001:2008 Registered Over 140 Permanent Full-Time Staff 100 Sub-Contracted Staff 140 Full-Time

3 Global Business Partners

4 Clients

5 Why is mapping required? Generate hydrodynamic models Calibrate models To produce flood risk maps Flood forecasting Flood risk management analysis To enable the design of flood relief schemes

6 Applying Different Methods and Tools For one result In Urban and Rural Environments Multipurpose Integrated Cost Effective Dynamic

7 Survey Methodologies Terrestrial and Satellite Positioning

8 Remote Sensing LiDAR Offers a significantly lower cost for large scale Mapping Widely used for extension of Flood Plain analysis Typical Flying height XY accuracy Z accuracy Ortho photo pixel size Lidar point density m +/-0.05m to 0.08m +/-0.05m to 0.08m 0.03m to 0.05m points per square meter m +/-0.08m to 0.10m +/-0.08m to 0.10m 0.05m to 0.10m points per square meter 700m +/-0.20m +/ m 1-10 points per square meter

9 3D Imaging Draped Orthophotos, High Res 3cm pixels DSM DTM Vegetation Penetration Real-time positioning and image collection to an accuracy of 10cm without ground control Horizontal and Vertical Scans

10 Economical method of accurate spatial data capture. Could provide a comprehensive source for all flood risk and coastal management data Not only on flood plains but also on flood defences and flood risk management assets, when being assessed and categorised

11 Client: OPW The Office of Public Works (OPW) National Catchment Flood Risk Assessment and Management (CFRAM) Programme

12 Scale of the Project

13 STATS (Six Contracts: 1, 2, 3, 5, Western SC2 and North West Neagh Bann) River Sections: 37,306 Open Sections: 19,500 Extended Gauge Sections: 1,100 Bridges: 1,800 Culvert: 1,500 Weirs: 600 Others: 2,300 Control Points: 260 Drawings: 5,500 Photos: 260,000 People: 100 Data: 500Gb+

14 Largest Survey of it s kind in Europe 54,000Km2 area 4190Km in length

15 Project Considerations Safely, Efficiently, Effectively Safety Approx 25,000 hours near water and no serious incidents Consistent Data 60 Survey Teams Efficient Delivery Short Timeline

16 Workflow Implementation Project team structure Insure consistent data Training and QA Checks Maximise time on site Technology/Reconnaissance/ Program/Crew Management Rigid workflows Continually reviewed Troubleshooting Geo-Information management and storage Protocols on data transfer Project structure protocols and awareness

17 Cross and long-sections (x,y,z spatial coordinates) on river channels and banks Structures (bridge, weirs, sluices) Flood Defences (walls, embankments) Photo and Videos Meta Data and GIS Survey Data Collected

18 Data Collection Protocols Assessment of specification Reviewed workflow and implemented new survey strategy Training and Standardised working practices Equipment Data collection Coding and fully digital recording On site QA protocols and verification of spatial data collected Gross error checks Real time data transfer Logistics and crew management

19 Equipment and Data Collection Trimble GNSS R6/R8 Total Station S6 Controller TCS3 Sonarmite Leica GS14 TS15i CS s GNSS D8 Disto Sonarmite

20 4 Orkney Fast Liner 19ft 6 Aluminium unsinkable 3.7m long by 1.3m wide Mokai Jet-propelled kayaks 6 Mercury 6hp 2 stroke with 12l fuel tank 4 Mercury 30hp 2 stroke with 25l fuel tank and 25ltr secondary tank Single man hovercraft Vessels

21 GIS Management Developed Scripts for QA Creation of Crew Packs Management Geo-tagged data Photos Notes Visual for PM

22 Data was collected and tracked in field and remotely loaded onto secure cloud. Project Management This method of data transfer enabled almost real-time survey processing. Data could be sent to the field crews through the cloud, directly to their loggers in the field.

23 Training and Standardised workflows Initial QA Check on survey data bespoke script Imagery renamed Output report created Report back to crews in real-time Bespoke River Module for Autodesk Civil 3D One step process Built in QA procedures Report back to crews and managed GIS Meta data All meta data related to cross sections and structures Additional photos Management tool Data Processing

24 A piece of cake?

25 Other Considerations Is your Mapping Accurate enough? Height systems with GNSS Is the OSGM02 Geoid sufficient? Are the long term studies been done for flood analysis of modelled topography, coastal and inland, as well as pluvial flooding events being affected by the local bias in the geoid corrector surface? Sea Surface Topography (SST) Altimeters Co-located GNSS and Tide Gauges

26 Orthometric Heights fundamental for the positioning of a point on the surface that best represents the topography In order to convert GPS geodetic coordinates the definition of the geoid is of critical importance for the user GEOID Gravimetric Geoid more suitable, as the time dependent gravity causes only small variations in the quasi/geoid model when compared to physical benchmarks which are subject to land uplift and local topographical changes True Equipotential Surface PPK/PPP Political and Economical will

27 Co located GNSS and Tide Gauges Currently Ireland is not part of the European Vertical Reference System (EVRS) as there are no co-located GPS-Tide gauges in operation that are associated with EUREF Help monitor the sea surface topography (SST) and land movement give excellent long term monitoring and evaluation of gravimetric geoids Accurate SST and the comparative land topography critical for flood mapping, and flood prevention Citizens will also benefit by knowing were the potential risks Insurance companies can process claims in a timely manner with access to accurate mapping and long term data. Sea Surface Topography (SST)

28 Questions & Answers Thank you for your attention, we welcome any questions! facebook facebook.com/murphysurveys Twitter twitter.com/murphy_surveys LinkedIn linkedin.com/murphy-surveys YouTube youtube.com/murphysurvey101

29 Learn more on our website!

30 Contact Us Kildare T:+353 (0) Belfast T:+44 (0) Cork T:+353 (0) London T:+44 (0)