Circular No. 70/2015/TT-BTNMT stipulates technical requirements for the operation of automatic meteorological and hydrological stations.

CIRCULAR

Technical regulations for the operation of automatic meteorological and hydrological stationsg

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Pursuant to the Ordinance on Exploitation and Protection of Meteorological and Hydrological Works dated December 2, 1994; the responsibility to manageGovernmental Decision No. 24/CP dated March 19, 1997 on detailed implementation of the Ordinance on exploitation and protection of meteorological and hydrological works;"b) In addition to the lists of public services issued according to the provisions of Clause 2, Article 4 of this Decree, specialized agencies under provincial People's Committees shall report to the provincial People's Committee for decision-making on amending, supplementing, or issuing the list of public services funded by the state budget within their jurisdiction and consistent with the local budget capacity within the approved budget by the Provincial People's Assembly, and send it to the Ministry of Finance and relevant ministries and sectors for supervision during implementation." Governmental Decree No. 21/2013/NĐ-CP dated March 4, 2013 on the functions, tasks, powers, and organizational structure of the Ministry of Natural Resources and Environment; At the proposal of the General Director of the National Meteorological and Hydrological Center, the Director of the Meteorological and Hydrological Administration, the Head of the Science and Technology Department, and the Head of the Legal Affairs Department;

Pursuant to DecreeNo. The Minister of Natural Resources and Environment issues this Circular on technical regulations for the operation of automatic meteorological and hydrological stations.uy This Circular includes "Technical Regulations for the Operation of Automatic Meteorological and Hydrological Stations".i The Minister, Heads of Ministries equivalent to Ministries, Heads of agencies under the Government, Chairpersons of People's Committees of provinces and centrally governed cities, Heads of units under the Ministry of Natural Resources and Environment, and related organizations and individuals are responsible for implementing this Circular. trTECHNICAL REGULATIONS FOR THE OPERATION OF AUTOMATIC METEOROLOGICAL AND HYDROLOGICAL STATIONS

Pursuant to DecreeNo. Circular No. 70/2015/TT-BTNMT dated December 23, 2015 of the Ministry of Natural Resources and Environment This Circular stipulates technical regulations for the operation of automatic meteorological and hydrological stations. Automatic meteorological and hydrological stations include stations for meteorology, hydrology, rainfall measurement, radiation, marine hydrology, and air environment.onThis Circular applies to state agencies, organizations, and individuals using automatic meteorological and hydrological stations. 1. An automatic meteorological and hydrological station is a system of equipment installed at meteorological and hydrological stations to automatically measure, collect, and transmit meteorological and hydrological data.

2. A measuring sensor is an element of the equipment or part of the measuring instrument."b) In addition to the lists of public services issued according to the provisions of Clause 2, Article 4 of this Decree, specialized agencies under provincial People's Committees shall report to the provincial People's Committee for decision-making on amending, supplementing, or issuing the list of public services funded by the state budget within their jurisdiction and consistent with the local budget capacity within the approved budget by the Provincial People's Assembly, and send it to the Ministry of Finance and relevant ministries and sectors for supervision during implementation." 3. Calibration of automatic meteorological and hydrological measuring instruments is the activity of evaluating and confirming the technical characteristics of the measuring instrument according to metrological measurement requirements. 4. Calibration of automatic meteorological and hydrological measuring instruments is the activity of determining and establishing the relationship between the measured value of the metrological standard and the measuring instrument with the value of the quantity to be measured.concerning the classification and determination of state management authority in the field of crop production5. Inspection of the operation of automatic meteorological and hydrological stations is the collection of work aimed at determining the operational status of the measurement system under specified technical conditions.Deputy ministers of ministerial-level agencies,6. Maintenance of automatic meteorological and hydrological measuring instruments is the regular and periodic activities carried out to maintain the equipment in normal operating condition. 7. Storage of automatic meteorological and hydrological measuring instruments is the work of storing spare parts and backup equipment to ensure they remain in the best condition without damage.concerning the classification and determination of state management authority in the field of crop productionArticle 3. Conditions for the operation of stations and observation points

1. Measurement factors of stations and observation points are defined based on the purpose, data needs, and actual conditions (details in Appendix 1 of this Circular). 2. Technical parameters of measuring equipment (details in Appendix 2 of this Circular).No.3. Measuring equipment must undergo initial calibration or verification before being put into use; during use, calibration or verification must be performed; after repair, testing/calibration must be conducted before returning to operation.

Article 1. 4. For measuring equipment that has not yet been calibrated or new types of measuring equipment not yet included in the network of operational meteorological and hydrological stations must have origin documentation and technical characteristics consistent with current technical standards; before operation, they must be tested, inspected, compared, and approved by the competent authority.

Article 2. This Circular takes effect from February 15, 2016.

Article 3. 5. Measuring equipment must have technical documentation and manufacturer software; maintenance, operation, and utilization instructions in Vietnamese.

TECHNICAL REGULATIONS

6. Automatic meteorological and hydrological stations must have management files.
(Issued together with CircularNo. 70/2015/TT-BTNMT dated December 23, 2015 of the Ministry of Natural Resources and Environment)

PART I

GENERAL PROVISIONS

Article 1. Scope of Regulation and Applicability

1. This Circular stipulates technical regulations for the operation of automatic meteorological and hydrological stations. Automatic meteorological and hydrological stations include stations for meteorology, hydrology, rainfall measurement, radiation, marine hydrology, and automatic air environment monitoring.

2. This Circular applies to state agencies, organizations, and individuals using automatic meteorological and hydrological stations.

Article 2. Interpretation of Terms

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1. An automatic meteorological and hydrological station is a system of equipment installed at meteorological and hydrological stations to measure, collect, and transmit automatic meteorological and hydrological data.

2. A measuring sensor is an element of the equipment or part of the measuring instrument.

3. Calibration of automatic meteorological and hydrological measuring instruments is the activity of evaluating and confirming the technical characteristics of the measuring instrument according to metrological requirements.

4. Adjustment of automatic meteorological and hydrological measuring instruments is the activity of determining and establishing the relationship between the measured value of the calibration standard and the measuring instrument with the value of the quantity to be measured.

5. Monitoring the operation of automatic meteorological and hydrological stations is the collection of tasks aimed at determining the operational status of the measurement system under specified technical conditions.

6. Maintenance of automatic meteorological and hydrological measuring instruments is the regular and periodic activities carried out to keep the equipment in normal operating condition.

7. Storage of automatic meteorological and hydrological measuring instruments is the work of storing spare parts and backup equipment to ensure they remain in optimal condition without damage.

Article 3. Conditions for Operation of Stations and Measurement Points

1. The measurement factors of stations and measurement points are determined based on the purpose, data needs, and actual conditions (details in Appendix 1 of this Circular).

2. Technical specifications of measuring instruments (details in Appendix 2 of this Circular).

3. Measuring instruments must undergo initial calibration or verification before being put into use; during use, calibration or verification must be conducted; after repair, testing, calibration must be performed before returning to operation.

4. For measuring instruments that have not yet been calibrated or new types of measuring instruments not yet included in the network of operational meteorological and hydrological stations, there must be origin documentation and technical characteristics consistent with current technical standards; before being put into operation, they must be tested, inspected, compared, and approved by the competent authority.

5. Measuring instruments must have technical documents and software from the manufacturer; maintenance, operation, and exploitation instructions in Vietnamese.

6. Automatic meteorological and hydrological stations must maintain management records.

Chapter II

TECHNICAL REGULATIONS

Article 4. Location of Stations and Measurement Points

1. For automatic weather stations and radiation stations, they must be unobstructed, not blocked by obstacles, and represent the natural conditions of the area where the station is located.

2. For automatic rain measurement points, they must be unobstructed, not blocked by obstacles that affect the measurement results.

3. For automatic hydrological stations

a) The location for water level measurement must ensure:

- Measuring the highest and lowest water levels;

- The riverbed relatively stable (little siltation or erosion);

- Not affected by rapids, waterfalls, trees, or other obstructions.

b) The location for flow measurement must ensure:

- No whirlpool phenomena and not affected by floating objects;

- The cross-section of the flow measurement line must ensure the measurement of river flow from the lowest water level to the highest flood level that has occurred;

- The section of the river must be straight and have a minimum length equal to three times the width of the water surface at the average water level;

- The riverbed must have no or few obstructions;

- Stable riverbanks; the river section must have no or small overflow areas; no inflow or outflow.

4. For automatic marine stations

a) The station location must be placed in an open sea area, ensuring natural conditions, and not obstructed in all directions.

b) The station location must represent a region or sea area regarding meteorological and marine characteristics.

5. For automatic air environment stations, they must be unobstructed and representative of the environmental quality and atmospheric composition of the area.

Article 5. Installation of Equipment

When installing, it is necessary to comply strictly with technical guidance documents for each type of measuring equipment.

1. For weather stations

a) Wind direction and speed sensors must be installed at a height of 10 m to 12 m above ground level, with the north side of the device aligned with true north.

b) Temperature and humidity sensors must be installed at a height of 1.5 m above ground level, ensuring unobstructed conditions and avoiding direct sunlight.

c) Rainfall sensors must be installed at a height of 1.5 m or more above ground level or the installation base, and the mouth of the rainwater collection container must be level.

d) Sunshine duration sensors must be installed at a height of ≥ 1.5 m above ground level, with the sensor axis aligned with true north-south, ensuring levelness and correct local latitude.

đ) Evaporation sensors must be installed at a height of 27 cm above ground level, and the mouth of the container must be level.

e) Atmospheric pressure sensors must be installed at a height of ≥ 1.5 m above ground level. The position of the atmospheric pressure sensor must be referenced to national absolute elevation.

g) Ground temperature sensors must be placed on the ground surface; deep soil temperature sensors must be placed at the required depths.

2. For rainfall measurement points

Rainfall sensors must be securely installed at a height of ≥ 1.5 m above ground level or the installation base, and the mouth of the rainwater collection container must be level.

3. For radiation stations

Radiation sensors must be installed horizontally at a height of ≥ 1.2 m above ground level. Shortwave and longwave reflection radiation sensors must be installed at a height of 1.2 m to 1.5 m.

4. For hydrological stations

a) Water level sensors:

- For non-contact water level sensors: the sensor must be fixed at a height higher than the highest water level previously observed by at least 1 m;

- For contact water level sensors: the sensor must be lower than the lowest water level previously observed by at least 20 cm;

- The water level measurement location must be referenced to national absolute elevation.

b) Flow sensors:

- For contact flow sensors, they must be securely installed on boats, ships, canoes, or structures to measure the entire cross-sectional flow of the river;

- For non-contact flow sensors, the sensor must be fixed at a height higher than the highest water level previously observed by at least 1 m.

c) Suspended sediment concentration sensors must be securely attached and suspended from a sufficiently heavy object to prevent movement with the current.

5. For marine meteorological stations

a) Wind direction and speed sensors must be installed at a height of 10 m to 12 m above ground level or the installation base.

b) Wave sensors must be securely installed at a depth three times greater than the maximum wave height at the measurement location.

c) For water level sensors:

- For non-contact water level sensors: the sensor must be fixed at a height higher than the highest water level previously observed by at least 1 m;

- For contact water level sensors: the sensor must be installed at a height lower than the lowest water level previously observed by at least 20 cm;

- The water level measurement location must be referenced to national absolute elevation;

- Temperature and salinity sensors must be installed or fixed on structures at a height lower than the lowest water level previously observed by at least 50 cm.

6. For automatic air environment stations

a) Air sampling sensors, dust sensors, and meteorological sensors (temperature, humidity, atmospheric pressure, rainfall) must be installed at a height of 1.5 m to 3 m above ground level.

b) Sensors for wind, direct radiation (SR), ultraviolet radiation (UV) must be installed at a height of 10 m above ground level;

c) Heads of greenhouse gas sampling tubes (CO, CO₂, CH₄, water vapor), O₃ and black carbon dust must be installed on dedicated poles at a height of 10 m to 12 m above ground level.

d) Measurement and analysis machines inside the station building must be equipped with air conditioning to maintain a stable temperature between 28 ⁰C and 30 ⁰C and low humidity between 40% and 50%.

7. Other Equipment

a) Solar panels must be installed in an unobstructed location, with the panel orientation being the direction receiving the most solar energy.

b) Antennas must be installed at a high, unobstructed location.

Article 6. Operation

1. Operating regime

a) Automatic meteorological and hydrological stations shall operate continuously 24/24 hours.

b) The frequency of measurements depends on the need for data usage.

2. Data transmission

a) Data measured at automatic meteorological and hydrological stations must be transmitted to agencies and units responsible for receiving, managing, exploiting, and using the data as prescribed.

b) The frequency of data transmission depends on the need for data exploitation.

3. Data storage

Data from automatic meteorological and hydrological stations must be stored, preserved, and used long-term as prescribed.

Article 7. Inspection

1. Regular Inspection

a) Regular inspections shall be conducted once every six months, including the following contents:

- Inspect sensors;

- Inspect the power supply system for the station;

- Inspect the lightning protection system;

- Inspect the information system;

- Inspect the data processing and storage system;

- Inspect the installation works of equipment.

b) Regular inspections must be carried out according to the correct procedures, recorded in files, and summarized in reports (details in Appendix 3 of this Circular).

2. Surprise Inspection

a) Conduct unscheduled inspections when the system does not operate normally or stops operating.

b) Unscheduled inspections must be recorded in files and reported (details in Appendix 3 of this Circular).

Article 8. Maintenance

Automatic meteorological and hydrological stations shall be maintained to ensure their functions and technical condition during normal operation of the equipment. The maintenance content is built based on the requirements of the manufacturer and the specific characteristics of each system of equipment during exploitation and use.

1. Maintenance includes the following basic contents:

a) Works: carried out once a year;

- Paint fences, columns with installed equipment, grease cables and bolts, ecu;

- Clean and dredge wells;

- Leveling heights for water level and atmospheric pressure measurement heads.

b) Equipment: carried out once every six months;

- Clean measurement heads, solar panels, lightning protection systems, cable connectors, transmitters, dataloggers, batteries, battery chargers;

- Calibrate equipment parameters after maintenance.

c) Replace spare parts and components periodically.

2. Maintenance must be carried out according to the correct procedures, recorded in files, and summarized in reports (details in Appendix 3 of this Circular).

Article 9. Repair and Replacement

1. Repairs and replacements of equipment are based on regular and unscheduled inspection records.

2. Equipment repaired or replaced must meet technical requirements.

3. After repairs and replacements, evaluation records must be established (details in Appendix 3 of this Circular).

Article 10. Preservation

1. Equipment and spare parts must be preserved in an environment according to technical guidance documents.

2. During periods of non-operation for repair or other reasons, equipment must be preserved under conditions similar to those when it operates normally (temperature and humidity); a technical condition check must be conducted every three months.

Chapter III

RESPONSIBILITIES FOR IMPLEMENTATION

Article 11. Management of Automatic Meteorological and Hydrological Stations

1. For national meteorological and hydrological stations managed by the National Meteorological and Hydrological Center:

a) The network of automatic meteorological and hydrological stations ensures stable operation and provides data to agencies and organizations as prescribed;

b) Responsible for managing and maintaining the operation of automatic meteorological and hydrological stations;

c) Strictly comply with all technical regulations stipulated in Chapter II of this Circular;

d) Develop annual maintenance plans, including budgets for maintenance, repair, and emergency replacement of automatic meteorological and hydrological stations, and submit them for approval by competent authorities.

2. For other automatic meteorological and hydrological stations managed by the investor, but not contrary to the provisions of this Circular.

Article 12. Technical management of automatic meteorological and hydrological stations

1. For national meteorological and hydrological stations managed technically by the National Meteorological and Hydrological Center:

a) Organize regular, spot checks, and evaluate the quality of data from automatic meteorological and hydrological stations according to regulations;

b) Conduct research, testing, evaluation, and propose the introduction of new measuring equipment and technology; consider and recommend the removal of unsuitable measuring equipment and technology;

c) Take the lead in compiling maintenance, operation, and exploitation guidance materials, organize training courses to enhance professional skills for those responsible for management, operation, and observation;

d) Take the lead and coordinate with relevant units to develop plans to maintain the operation of automatic meteorological and hydrological stations according to current standards;

e) Implement changes to measurement modes and data transmission of automatic meteorological and hydrological stations.

2. For other automatic meteorological and hydrological stations managed by the investor, but not contrary to the provisions of this Circular.

Article 13. Implementation Organization

1. Organizations, individuals using automatic meteorological and hydrological stations must prepare reports on station operations and submit them to the Ministry of Natural Resources and Environment (through the General Department of Meteorology, Hydrology, and Climate Change) before December 15 each year.

2. The General Department of Meteorology, Hydrology, and Climate Change is responsible for guiding, urging, and inspecting the implementation of this Circular.

3. During the implementation of this Circular, if there are difficulties or obstacles, agencies, units, organizations, and individuals should reflect these issues to the Ministry of Natural Resources and Environment (through the General Department of Meteorology, Hydrology, and Climate Change) for consolidation and submission to the Minister for consideration and decision./.