Cadastral Survey in the 21 st Century. Gavin Adlington. Land Program Team Leader Europe and Central Asia Region (ECA)

Transcription

1 E-learning Series Cadastral Survey in the 21 st Century June 3, 2010 Gavin Adlington. Land Program Team Leader Europe and Central Asia Region (ECA) The World Bank

2 Content : Purpose of cadastral survey Error theory 19th and 20 th Centuries 21 st Century technology Conclusion 2 RPM-50

3 Purpose of Cadastral Survey 1. Real Estate Property Taxation 2. Protection of Property Rights 3. Land Use Control and Monitoring 4. Multi-purpose p For each we need to know what is needed dd for the task.

4 Property Taxation To derive income for government Cover every property no gaps Value Area? Maybe depends on valuation methodology Accuracy of measurement need cost/ benefit for difference in cost of collecting the tax against income derived.

5 Protection of Property Rights To enable the real estate market to operate with efficiency Cover every property that has private property rights. No overlaps or duplications Define boundaries in such a way that they can be replaced in time of dispute.

6 Land Use Control and Monitoring To ensure that land is used in a sustainable manner. Ensure land is not laid waste. Ensure land is used for the overall benefit of society. Need to cover all land, but data content and accuracy of information depend on government policy.

7 Multi-Purpose Cadastre To maximise efficient use of spatial information Provide the where, who, what basic information to multiple users. Provide better service to the public. Reduce duplication of costs and time for information gathering. Accuracy dictated by the level needed by individual id cadastres.

8 We do not require high accuracy of measurement for any of these cadastres. But We have very good reason for measuring to high standards

9 Content : Purpose of cadastral survey Error theory 19th and 20 th Centuries 21 st Century technology Conclusion 9 RPM-50

10 Gross Errors Error Theory Random Errors Systematic Errors. It is the systematic errors that require us to be careful in measurement.

11

12

13

14

15

16 and we measure as accurately as we can. To reduce the likelihood of this happening we work from the whole to the part utilizing first/ second/ third/ fourth order networks, and local networks within towns.

17 Content : Purpose of cadastral survey Error theory 19th and 20 th Centuries 21 st Century technology Conclusion 17 RPM-50

18 Thanks to John Tomasowa of Dutch Kadaster for these photographs. 19 th and 20 th Centuries

19

20 : How was the old survey done? Was it checked? What accuracy should we expect to see? A boundary is not really fixed unless a second survey agrees with the first! 20 RPM-50

21 Content : Purpose of cadastral survey Error theory 19th and 20 th Centuries 21 st Century technology Conclusion 21 RPM-50

22 21 st Century GNSS LIDAR Orthophoto 3-D imagery Geoeye image

23 : Errors do not accumulate No need for geodetic network! Accuracies improving Availability increasing It will only get easier, quicker, more available and more accurate. Need to rethink our procedures and standards. 23 RPM-50

24 : It is now easier to re-measure than to investigate i where errors have occurred in the past and try to fix them. Accuracy is no longer a problem with modern instruments. But you still have to meet the owners and walk the boundaries! 24 RPM-50

25 In case of dispute over boundaries: Rules of Evidence unlikely to change Where do owners and past owners say the boundary is? What physical features on the ground show where the boundary is? What does the description in the deed say? What do the survey plans show? Coordinates? 25 RPM-50

26 And Remember Cadastre Cadastres will show the complete legal picture including public rights and restrictions 2. The separation between maps and registers will be abolished. 3. Cadastre mapping will be dead modeling has arrived. 4. Paper and pencil (or ink!) will have disappeared. 5. Cadastre will be highly privatized, with private and public sector working together. 6. Cadastre will work on the basis of cost recovery 26 RPM-50

27 Content : Purpose of cadastral survey Error theory 19th and 20 th Centuries 21 st Century technology Conclusion 27 RPM-50

28 Conclusion When surveying in the 21 st century we have to know how previous surveys were completed. : Technology is changing rapidly keep up to date and make good use of it. Go back and think what is actually needed for this work 28 RPM-50

29 That s it Folks Many Thanks