Requirements for the accuracy of cadastral maps according to new regulations in Vietnam from January 15, 2025

Requirements for the accuracy of cadastral maps according to new regulations in Vietnam from January 15, 2025​ (Image from the internet)

On November 26, 2024, the Minister of Natural Resources and Environment of VIetnam issued Circular 26/2024/TT-BTNMT regulating technical specifications for surveying and establishing cadastral maps.

Requirements for the accuracy of cadastral maps according to new regulations in Vietnam from January 15, 2025​

The accuracy requirements for cadastral maps are set forth in Article 8 of Circular 26/2024/TT-BTNMT as follows:

- The mean square error of the survey station's position (measuring station point) relative to the initial point must not exceed 0.1 mm on the desired map scale.

- The error in representing the corner points of the map frame, intersections of the km grid, coordinate points (national coordinate points, cadastral points, control survey points) on digital cadastral maps is defined as zero (no error).

For paper cadastral maps, the deviation in dimensions represented on the map compared to theoretical values must not exceed 0.2 mm for inner frame dimensions, and 0.3 mm for the diagonal dimensions of the inner frame on the map.

- The positional error of any point on the parcel boundary shown on the digital cadastral map compared to the nearest control survey point must not exceed:

+ 5.0 cm for 1:200 scale cadastral maps;

+ 7.0 cm for 1:500 scale cadastral maps;

+ 15 cm for 1:1,000 scale cadastral maps;

+ 30 cm for 1:2,000 scale cadastral maps;

+ 150 cm for 1:5,000 scale cadastral maps;

+ 300 cm for 1:10,000 scale cadastral maps.

- The mutual error between two parcel points on the digital cadastral map compared to the dimensions measured in the field with electronic total stations or steel tape is regulated in Appendix 03 attached to Circular 26/2024/TT-BTNMT.

- The area deviation limit of a parcel on the digital cadastral map compared to areas directly determined in the field with electronic total stations is regulated in Appendix 04 attached to Circular 26/2024/TT-BTNMT.

- When inspecting the quality of cadastral map products, the number of parcels with errors as specified in clauses 3, 4, and 5 of Article 8 of Circular 26/2024/TT-BTNMT having values equal to or close to the maximum limit (from 90% to 100%) must not exceed 25% of the total number of parcels inspected; in all cases, the errors must not be systemic.

- The error values and maximum error limits specified in clauses 3, 4, and 5 of Article 8 of Circular 26/2024/TT-BTNMT can be reduced for areas with denser than average parcel density for the measuring zone or when individually surveying or rectifying parcels; the requirements for errors and maximum error limits must be clearly reflected in the technical design - cost estimate, task plan.

Establishing a measurement task plan for creating cadastral maps in Vietnam from January 15, 2025

- The measurement task plan for creating cadastral maps is established based on the evaluation and analysis of documents, data, and information related to the task.

- The main content of the task plan includes:

+ The basis for establishing the task plan;

+ Objectives, requirements, scope of the task;

+ Determination of the workload for each task item;

+ Technical solutions for implementation.

For cases involving the extraction of cadastral maps, the task plan must include solutions for editing cadastral map sheets containing parcels extracted for mapping and the extracted map sheets;

+ Implementation costs;

+ Product verification, packaging, and submission;

+ Organization of implementation.

(Article 10 of Circular 26/2024/TT-BTNMT)

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