Analysis of the 2017 Survey of Local Geodetic Network Employees
There are three main lines of action in the field of maintenance and repair of the local geodetic network. The first is the survey of the local geodetic network and the decision of the municipality regarding the local geodetic network. The second direction is knowing what to do when local geodetic points are destroyed. The third is the development of the local geodetic network. Based on the above, an explanation of the steps to be followed and an insight into the information gathered from the survey will be provided below.
In March 2017, the Latvian Geospatial Information Agency (hereinafter - LGIA) organized a survey of local government employees responsible for the local geodetic network (hereinafter - local network) on the work done in the area of the local network. based on Cabinet of Ministers Regulations No. 497 “Local Geodetic Network Regulations” (hereinafter - the Regulations). 104 employees responsible for local network responded to the survey. A previous similar survey was conducted in 2014.
The Regulations determine the key actions that should be monitored by the employee responsible for local network. The LGIA, for its part, provides methodological support to these staff in solving local network issues, as long as they contact the LGIA specialists.
Each municipality must have an employee responsible for local network and it is important that the municipalities provide information to the LGIA on the change of staff. The survey showed that in most municipalities (more than half) the responsible employees have been changed.
The LGIA provides free consultation only to the responsible staff or to their resolution to another person. Any activity that takes place within the local network must be coordinated with the responsible person who has to be informed about each geodetic point in the territory of his municipality. As employees change, the previous information is not always passed on and every new employee has to start over.
In addition, the LGIA publishes a list of those responsible for the local network on its website, and its relevance depends directly on the information provided or not provided by each municipality. Ideally, the employee or municipality should inform the LGIA of the termination of employment with the municipality. The municipality then sends a letter appointing a new employee.
The designation of municipal staff began in 2010, and in 2012 all municipalities had employees responsible for local network. According to the 2017 survey, 8 municipalities do not have a responsible officer at all, which is in contradiction with the information available in the LGIA. This means that municipalities either do not understand or simply forget that when the staff assigned to the responsibility for the local network changes, it is necessary to send the LGIA information on the change of staff.
From the survey: in 41 municipalities the person responsible for the local geodetic network has not changed since its designation; 45 municipalities perform these duties for 1 to 4 years; 10 municipalities work in this position for up to 1 year, 8 municipalities do not have a responsible employee at all.
The maintenance or improvement of a local network must begin with its identification. This means gathering and retrieving all possible information about the geodetic points in the municipal area, and surveying them - an area search and an assessment of the condition (whether the point is suitable for future use).
Between 2010 and 2013, the LGIA, by means of a deed of transfer, issued to all municipalities information in its possession on the local geodetic network recorded on electronic media (CD or DVD), which is:
- information on polygonometry points that were transferred from the SLS;
- leveling point lists and diagrams in .dgn format;
- triangulation (T1 - T4) point lists and diagrams;
- global positioning (G3) point lists and diagrams;
- list of documents in the LGIA Archive and Material Circulation Fund;
- digitized polygonometry and leveling catalogues and reports available from the LGIA Archive and Material Circulation Fund.
Disks with such information should be in each municipality, and it would be best if they were kept by a employee responsible for local network.
The next step in gathering information is to identify and obtain all possible information about geodetic points from surveyors practicing in the municipal area, who in many cases could provide relatively up-to-date information.
The 2017 survey showed that in addition to the information provided by the LGIA and surveyors, information was also obtained from the SLS and other institutions, such as the municipalities themselves, the Building Board, the Land Survey Data Center (MDC) and land surveying firms. However, there were also municipalities that did not identify the information.
After the information has been collected, a survey of the local network should be conducted to determine its actual condition - whether points are in the area and in what condition.
No geodetic characteristics of any local area network point shall comply with paragraph 4 of the Regulations without optimization, but the point itself may be valid. Surveying of geodetic points can be carried out by persons without a certificate in surveying, such as students of geodesy, land surveying, earth science and related fields. It can also be done by municipal employees themselves or entrusted to surveyors or surveying firms.
In any case, after the survey, a survey of the local network should be prepared and agreed upon by the employee responsible for local network, if desired, but may not be submitted for opinion to the LGIA. The local network identification process is governed by Part II of the Regulations "Local Area Network Identification and Evaluation". According to the Regulations, the initial identification and evaluation of the local network was due by 2014.
From the survey: the survey of the local geodetic network has been completed in 56 municipalities, partly in 23 municipalities, but not in 25 municipalities.
After approval of the local network survey and survey report, the municipality shall decide on the future of the local network in accordance with paragraph 17 of the Regulations. The municipality may decide to carry out the development of the local area network on its territory at once (paragraph 17.1 of the Regulations) or to do so gradually within the framework of routine surveying and construction-related projects (paragraph 17.2 of the Regulations). The decision shall be based on the results of the local network survey and shall include all points which have survived and which have been confirmed. The areas covered and not covered by the decision must be specified.
The main criteria for making a decision are:
- existing building - dense or loose, single-storey or multi-storey, etc .;
- prospective building;
- problems with existing geospatial data - cadastral and topographic scale 1:500 - these data directly depend on the accuracy of the local geodetic network.
The survey shows that only 18 municipalities have decided on the improvement of the local network, but 86 municipalities have not yet done so.
In accordance with Part VI of the Regulations, entitled "Circulation of Local Area Information", the municipality shall ensure the updating of the Local Geodetic Network Database (hereinafter - VTDB).
From the survey: in 76 municipalities the information is not updated in the database, while in 28 municipalities it has been done.
The VTDB is already part of the local network points in the municipality area, so after the survey it is necessary to supplement the existing information and enter new points. The "Historical data" section should be updated with the surveyed geodetic points. Conversely, if a point is not yet in the database, it must be entered.
There have been two cycles of seminars on the local network and VTDB in all planning regions - in 2012 and 2014, where LGIA staff provided explanations on the local network and work with VTDB (presentations from the seminars can be found at: 2010, 2012 un 2014).
From 2014, access to VTDB is only with passwords. The LGIA has sent all municipalities access details - a username and a password to access and update the database. If the access details of a municipal employee have been lost or have not changed at all, the application must be sent to the LGIA for granting or canceling the requisites. The application for cancellation of the requisites must be sent by the municipality to the LGIA in cases where the employee terminates the employment relationship. Application forms can be found at https://vt.lgia.gov.lv/.
The number of geodetic points in recent years due to road and street reconstruction, building insulation, reconstruction works and similar economic activities is very dynamic, so it is difficult to talk about the specific number of geodetic points. It can only be recorded for a specific point in time, that is, at the time of the survey. It is important that information is regularly updated by the VDTB, both after the survey has been conducted to determine whether the point actually exists, has been destroyed or damaged, and when receiving information from surveyors who use geodetic points in their daily work.
If a decision has been made on the local network in the municipality (specifically one of the two types of local network improvement), work on the local network maintenance process can continue, where the next step is to prepare a description of the local network improvement.. This may be performed by a person whose qualification corresponds to the qualification specified in Section 10, Paragraph 3 of the Geospatial Information Law. The prepared description is definitely approved by the municipality as it will serve as the basis for further development of the entire local network. If desired and for security reasons, the description may be submitted to the LGIA for its opinion.
The LGIA reviews the descriptions for compliance with the Regulations - whether the correct methods of geodetic measurement are chosen, new geodetic points are properly designed, existing ones are fully utilized, etc. Local network development descriptions should also be prepared when local network points are to be destroyed during the construction process.
The description of the local area network development follows the local area network development process, which concludes with the development report, which must be submitted to the LGIA for the opinion on the local network development compliance with the regulations (paragraphs 45 and 46 of the Regulations).
Although the protection of geodetic points is determined by the Protection Zones Law, the public has not yet developed a proper attitude towards geodetic points. Therefore, every effort should be made to trace all activities that take place in the municipality in connection with all types of construction. It is necessary to actively cooperate with the Building Boards and try to ensure that the responsible employees are involved in the provision of construction project conditions and at the end of construction works in the process of coordination of the handover of objects. The responsible employees must also find an opportunity to provide information about the local network points by developing spatial plans, local plans and detailed plans, issuing conditions to the developers of these plans.
One of the responsibilities of the employee responsible for local geodetic network in the municipality is to monitor whether information on local network points is included in spatial plans, local plans and detailed plans, as well as in all construction-related projects. This is necessary to comply with the Protection Zones Law, which establishes operational protection zones around geodetic network points, which in turn would protect the geodetic point from destruction and help municipalities to develop the local geodetic network.
From the survey: information has been provided to the developers of spatial plans, local plans and detailed plans in 61 municipalities, however, this has not been done in 43 municipalities. Conditions and approvals for local geodetic network points in various construction-related projects have been provided in 67 municipalities, but not in 37 municipalities.
According to Article 33 (2), Article 35 (6) and Article 49 of the Protection Zones Law, any economic activity in the protection zone of a geodetic point must be coordinated with the owner of the geodetic point. The points of the local network are the property of the local government, therefore all activities in the protection zone of the geodetic point must be coordinated with it. If a geodetic point has to be destroyed within the construction project, the builders are obliged to cover the costs of installing a new point instead of the point to be destroyed in accordance with the regulations.
In a densely populated area, at least 10 local network points shall be involved in the development. In sparsely populated area, individual points can be improved one by one. Therefore, it is important to coordinate all construction projects in the municipality with the employee responsible for the local network. Whether it will be necessary to install a new point in place of the point to be destroyed, in which place it is necessary to install it, is determined by the employee responsible for the local network in the municipality.
From the survey: the answers obtained in the survey show that within the framework of construction works, the points of the local geodetic network have been moved in 33 municipalities, but 71 municipalities have not used this opportunity.
As the points of the local geodetic network are located both in municipal territories and in private territories or properties, informing the owner of the territory where the geodetic point is located is a very important factor for the preservation of geodetic points. Although the Protection Zones Law defines protection zones around all geodetic points, often the owner of the territory is not even aware that he owns such. Therefore, it is important to inform property owners. It is also determined by Paragraph 48 of Cabinet of Ministers Regulations No. 497 “Local Geodetic Network Regulations”.
From the survey: 36 municipalities have informed owners, but 68 municipalities have not done so.