Presentation on theme: "5 th Trans Tasman Survey Conference - Cairns 2006 SURVEY ACCURATE CADASTRAL PARCEL NETWORKS AS THE BASE LAYER FOR ENHANCED GIS Council & Service Authority."— Presentation transcript:
5 th Trans Tasman Survey Conference - Cairns 2006 SURVEY ACCURATE CADASTRAL PARCEL NETWORKS AS THE BASE LAYER FOR ENHANCED GIS Council & Service Authority Case Studies and the role of the Surveyor Ian Harper - Geodata Information Systems Pty Ltd, Australia Craig Sandy – ESRI Australia
5 th Trans Tasman Surveying Conference – Cairns 2006 1.BACKGROUND TO GIS CADASTRAL DEVELOPMENT 2.CASE STUDIES - The creation of Survey Accurate Cadastral networks Northern Territory - A Coordinated Cadastre as a prelude to Legal parcel Coordinates. Hunter Water Corporation - A major water utility with a long history of developing and working with an accurate cadastral fabric. Gosford City Council – A rural LGA becoming part of the Sydney urban sprawl. Gloucester Shire Council – A small LGA in rugged terrain with big errors in its DCDB. 3. FUTURE DIRECTIONS FOR THE SURVEY PROFESSION AND GIS CADASTRAL MANAGEMENT
GIS CADASTRE BACKGROUND 10 years ago GIS systems were spatially ‘pictorial’. Screen graphics were used to add data and was spatially referenced to the existing database information.
CURRENT STATUS The spatial management of cadastral databases has not kept pace with the improvement in spatial quality provided by GPS, photography and other modern data collection technologies.
THE ESRI – GEODATA ALLIANCE The process of integrating the GEODATA ‘GeoCadastre’ software into the ESRI suite of GIS software is an initiative to bring survey accuracy to GIS cadastral modelling.
THE ESRI – GEODATA ALLIANCE ESRI GEODATA INFORMATION SYSTEMS P/L A Company formed in 2000 to promote the Survey (GeoSurvey) and Cadastral Adjustment (GeoCadastre) software developed over the last 20 yrs by Michael Elfick & Michael Fletcher for a user group of Survey Companies in Australia.
MOVING FORWARD The new workflows in the ESRI Survey Analyst - Cadastral Editor (to be released worldwide in 2007) adopts survey methodology from the ‘GeoCadastre’ process. This provides the most accurate model of the legal cadastre for use in GIS systems
THE ESRI – GEODATA ALLIANCE The result for ESRI was a completely new data model for parcels built within a GIS database. Instead of a parcel ‘shape file’ as the basic unit, a seamless cadastral fabric is created which maintains the original survey plan measurements as defining the parcel boundaries.
CASE STUDY No.1. - NORTHERN TERRITORY A coordinate based cadastre created from existing survey plan measurements is nearing completion. »Locality sketch »Show width & ht 550 Miles 1,500 Miles
NORTHERN TERRITORY Why a Coordinated Cadastre? Coordinate based GPS surveys have replaced conventional measurement survey techniques. A single surveyor with GPS has replaced a field party of 8.
NORTHERN TERRITORY The goal of a Coordinated Cadastre Due to their size, some Pastoral Leases are all ready defined by Latitude and Longitude. ie defined spatially by geodetic reference frame.
NORTHERN TERRITORY Coordinated Cadastre – The Statutory Process The NT has enacted legislation to “legalise” the derived coordinates. As areas reach a required standard of accuracy they are “proclaimed” The coordinates then become the primary evidence as to the location of parcel corners.
NORTHERN TERRITORY LICENSED SURVEYORS ACT 2004 PART VI – PRACTICE OF LAND BOUNDARY SURVEYING 46A. Coordinated survey areas (1) The Surveyor-General may declare an area of land in the Territory to be a coordinated survey area. (2) A declaration under subsection (1) is to be notified in the Gazette and takes effect on the date specified in the notice. (3) A survey within a coordinated survey area is to be in accordance with an approved methodology to delimit land boundaries by geodetic coordinates or with another approved system of delimitation.
NORTHERN TERRITORY Current Status Local surveyors were involved in the process and supported the Department of Planning and Infrastructure.
The Northern Territory has moved from an 18 th Century cadastral system to a New Millennium survey system.
CASE STUDY No.2 HUNTER WATER CORPORATION Hunter Water Corporation (HWC) is a water and wastewater Utility on the Central Coast of NSW covering 5 local government areas. HWC has a long history of the creation and management of survey accurate cadastral networks.
Hunter Water Corporation Area of operations: 5000 Sq kms Population serviced: 496,000 Properties serviced: 209,000. Pipe network details: Water-mains - 4,300 kms Sewer-main - 4,400 kms
HUNTER WATER AUSTRALIA - Historical – 1970’s The pipe networks and cadastral marks were located by survey and connected to the NSW Trigonometric network. Coordinates for parcels and assets were generated using hand calculators and base sheets were hand drafted from those coordinates.
HUNTER WATER AUSTRALIA - Plat Coordinated Manually
HUNTER WATER AUSTRALIA - Historical – 1980’s Computers and CAD superseded calculators and hand drafting. The same techniques used: bearings and distances shown on survey plats were keyed into a coordinate geometry software package. This approach had a major shortcoming - the survey information and the thought processes which led to particular choices for adjusting misfits between parcels, was lost..
HUNTER WATER AUSTRALIA - Historical – 1990’s The digitised Digital Cadastral Database (DCDB) was created by the NSW Lands Dept. Whilst this was a significant achievement, for HWA it revealed unacceptable spatial accuracy between the surveyed and digitised parcel boundaries.
HUNTER WATER AUSTRALIA - Historical – 1990’s HWA decided to create their own coordinated cadastre. Accuracy required: The width of a backhoe bucket ~ 0.5 m
HUNTER WATER AUSTRALIA - Historical - 1994 Hunter Water adopted the GeoCadastre process (Survey Analyst – Cadastral Editor) for cadastral database mapping. Important selection criteria were: Survey plan information entered into the adjustment was weighted according to accuracy When the original field survey locating the pipe network was only related to the cadastre, those survey measurements were retained in the adjustment – ie. as new accurate survey data is included, updated coordinates for the parcel fabric and the pipe network are produced.
HUNTER WATER AUSTRALIA - CURRENT As a condition of final approval for new water & sewer construction, a spatially accurate electronic dataset of the asset and the cadastre is lodged with HWA by a Registered Surveyor. The data is supplied in a specified format to ensure compatibility. Each day Hunter Water adds data from approximately five new survey plans to the DCDB, equivalent to 3,500 new parcels per year. Maintenance and updating of the DCDB is achieved with a resource of 0.75 staff.
HWA Operations - 1 Field survey recording asset locations is simplified by the need to be only related to the Map Grid of Australia (MGA) Boundary definition is not required to determine asset location.
HWA Operations - 2 Maintenance crews with field laptops, can view and print the current GIS data set. The GIS dataset on the laptops is upgraded weekly.
HUNTER WATER AUSTRALIA - Outcomes Hunter Water now provide on-line: ‘Dial Before You Dig’ – requests for asset location information is returned via an automated email and facsimile system linked to the GIS. Property water & sewer connection point plans needed for the transfer of land ownership are sent electronically to solicitors.
HUNTER WATER AUSTRALIA - Outcomes SURVEYORS CONTROL THE GIS CADASTRAL DATABASE
HUNTER WATER AUSTRALIA - Outcomes Hunter Water’s survey accurate cadastre is shared by Energy Australia (Australia’s largest energy distributor). With 20 years experience in cadastral management, HWA now consults to other Councils and Authorities. Cadastral upgrade projects have been undertaken across Australia.
GOSFORD CITY COUNCIL - Background An historically rural area undergoing significant urban, commercial and infrastructure growth as a ‘dormitory’ suburb to the Sydney urban sprawl. Population - approx 163,000 Land parcels - 70,000 ( 40,000 urban) The GIS system is maintained by 2-4 corporate staff. Gosford CC have now commenced a program of a gradual upgrade of their GIS Cadastral Layer.
GOSFORD CITY COUNCIL - Background The existing DCDB was out by 1 - 5 metres in urban areas and up to 20 metres in rural zones. In 2005, high resolution Aerial Photography was acquired. The DCDB was found to be visually and legally unacceptable for Council, particularly when dealing with planning issues relevant to multi-million dollar waterfront development.
GOSFORD CITY COUNCIL - Benefits In the completed areas Council have accurately aligned cadastre & photography. Engineering design layout (roundabouts etc) is being completed in the office. Survey information collected by Council surveyors is now being added to the GIS. Previously, they saw no point in populating the GIS with ‘work as executed’ data due to the poor alignment with the cadastre.
CASE STUDY – 4 GLOUCESTER LOCAL GOVERNMENT AREA – Location Plan
GLOUCESTER LOCAL GOVERNMENT AREA - Background Gloucester LGA is a rural Council generally located in hilly & mountainous terrain. Includes part of the Barrington Tops World Heritage Rainforest and Wilderness areas. The total LGA population is over 4,900 with Gloucester Township containing over half (2600).
GLOUCESTER LGA - GIS Background Gloucester Council has a total of 20 administration staff - includes 1 GIS operator. Council was aware of the poor quality of the existing DCDB and there was no indication of improvement of that situation in the near future.
Gloucester LGA - The Process GEODATA completed a contract to capture and convert all historical and current parcels within the Gloucester LGA using GeoCadastre software.
GLOUCESTER LGA - Project Issues Some old Title plans (from late 1800’s) were illegible in standard electronic format. Cost implications to retrieve legible original documents from NSW Government. Some plans had little or no survey information. Where boundaries were the bank of the creek, many surveys did not measure across the creek – ie no connectivity between survey plans.
GLOUCESTER LGA - Project Outcomes 4,264 historical & current parcels were captured and converted. Discrepancies of up to 200 metres were found between the DCDB and the numeric cadastre created. Plans of any development work lodged with Council are required to be spatially accurate (endorsed by Registered Surveyor).
THE FUTURE State Governments have a role to host a unique cadastral database and maintain the standards Local Government Authorities and local Utilities are best placed to control the domain of creating and maintaining their own databases. Local Government appreciates the role that the GIS database plays in their operations. There must be recognition of the true economics of creating a survey accurate GIS cadastre relative to the ongoing costs in maintaining and working in a database of poor quality.
THE RELEVANCE TO THE SURVEY PROFESSION Recognise the changing circumstances which require a shift of focus in individual and corporate practices with respect to CAD & GIS databases. Business opportunities supplying skills to database creation & maintenance
There is an expectation within the GIS industry that software will resolve the issue of cadastral integrity. Software will provide the tools but alone will never provide the best solution.
The importance of Surveyors The work of the Survey Profession creates the fundamental blocks for GIS systems and we must recognise that surveyors are best placed to control that foundation.
ACKNOWLEDGEMENTS Michael Elfick, Wallalong, NSW, AUSTRALIA Peter BartlettHunter Water Corporation – Newcastle, Allan Large NSW, AUSTRALIA Graeme Samuels Darren SanterGosford City Council - NSW, AUSTRALIA Glenn Wilcox Gloucester Shire Council - NSW, AUSTRALIA Ben Roberts Julian Schneider Garry WestSurveyor General, Darwin, NORTHERN TERRITORY Tim HodsonESRI – Redlands, CALIFORNIA Christine Leslie ESRI – Redlands, CALIFORNIA Roger LeeGeodata Information Systems P/L – Newcastle, NSW, AUSTRALIA