Circular No. 14/2010/TT-BTNMT stipulates the procedures for flood forecasting

CIRCULAR

Provisions on flood forecasting procedures

_______________________

MINISTER OF NATURAL RESOURCES AND ENVIRONMENT

Pursuant to Decree No. 25/2008/NĐ-CP dated March 4, 2008 of the Government stipulating the functions, tasks, powers, and organizational structure of the Ministry of Natural Resources and Environment;

Based on Decision No. 245/2006/QĐ-TTg dated October 27, 2006, issued by the Prime Minister, regarding the regulations on tropical depression, typhoon, and flood warnings;

Considering the proposal of the Director of the National Hydrology, Meteorology, and Climate Change Agency and the Head of the Legal Department,

c) Enterprises may be granted permission for no more than one block out of the total three dual-frequency blocks (FDD) B

Article 1. Scope of regulation and applicable subjects

1. This Circular stipulates the procedures for monitoring, analyzing, and forecasting floods in river systems within the territory of Vietnam.

2. This Circular applies to:

a) Organizations and individuals implementing flood forecasting work under the Ministry of Natural Resources and Environment;

b) Organizations and individuals permitted to conduct flood forecasting within the territory of Vietnam based on the provisions of this Circular and their actual conditions and capabilities.

Article 2. Monitoring and identifying the causes of flooding

1. Signs indicating the occurrence of floods

a) Weather patterns causing rain and floods.

b) Continuous heavy rainfall over a wide area with average basin rainfall capable of generating floods.

c) Flooding has already occurred at upstream stations.

d) Flood intensity at the forecast location increases.

2. Monitoring and identifying floods

a) When the flood level reaches warning level I and there is a possibility of reaching warning level II on one of the main rivers nationwide, the flood forecaster (hereinafter referred to as the forecaster) reports to the relevant authority with jurisdiction.

b) When the flood level exceeds warning level II and there is a possibility of reaching warning level III, the forecaster reports once daily to the relevant authority with jurisdiction in writing.

c) When the flood level reaches warning level III and continues to rise rapidly, the forecaster reports twice daily to the relevant authority with jurisdiction in writing.

d) When the water levels in reservoirs approach normal pool levels and it is forecasted that inflow to the reservoirs will continue to increase rapidly or if flash floods due to dam or dike breaches pose a danger to society, the forecaster and the relevant authority with jurisdiction must immediately issue a special dangerous flood warning bulletin.

đ) After issuing the bulletin, the forecaster must continue to monitor to assess the subsequent flood levels.

3. Flood duty watch

When there is a flood or when a flood is forecasted to occur, the organization conducting the forecast must organize a flood duty watch.

Article 3. Analyzing rainfall and floods

1. Analyzing weather and rainfall conditions:

a) Analyzing weather patterns causing rainfall.

b) Calculating average basin rainfall.

c) Determining rainfall intensity.

d) Identifying areas where rainfall has occurred.

đ) Identifying areas where rainfall will occur.

e) Determining forecasted rainfall amounts for the next 6 hours, 12 hours, 18 hours, and 24 hours.

g) Determining the start and end times of rainfall.

2. Analyzing flood conditions

a) Plotting rainfall, water level, and flow rate processes for various locations from upstream to downstream.

b) Calculating average and maximum flood intensities over 6 hours.

c) Calculating flood amplitude.

d) Calculating flood transmission time on each river section to determine peak flood appearance time.

đ) Identifying areas where flooding has occurred.

e) Determining the degree of flooding that has occurred according to various flood scenarios.

Article 4. Forecasting floods

1. Collecting and processing data

a) Continuously updating observational data; calculating and summarizing.

b) Processing and verifying cases of missing, delayed, or erroneous data.

c) Recording in writing the collection and processing of data.

2. Conducting flood forecasts

a) Forecasting floods using the following methods:

- Rainfall-flood relationship method;

- Water level or flow rate corresponding relationship method;

- Regression method.

b) Forecasting floods using the following models:

- Centralized hydrological parameter model;

- Distributed hydrological parameter model;

- Simulation model;

- Hydraulic model.

c) Forecasting floods based on the following characteristics:

- Maximum and average flood amplitude, intensity;

- Water level (flow rate) values corresponding to the forecasted time, compared with warning levels and types of floods;

- Peak flood value and time of appearance; compared with warning levels and types of floods.

d) In cases where there is a possibility of large or extremely large floods, the forecaster selects similar flood events from historical observation data to develop possible flood scenarios based on the following factors:

- Weather patterns causing rainfall;

- Rainfall extent and intensity over the basin;

- Flood extent and intensity over the basin;

- Time of flood occurrence.

3. Adjusting forecasts

a) Calculating errors between observed and forecasted values from previous forecasts; evaluating forecast results based on allowable errors specified for each forecast location.

b) Analyzing reasons for inaccurate forecast results.

c) Updating forecast error values, analyzing observed processes and error processes.

d) Adjusting forecasts using the following methods:

- Correlation diagram method;

- Regression method;

- Kalman filtering method.

4. Selecting forecast values

a) If at a location, different forecasting methods yield results that are not significantly different, analyze and select the forecast value; do not average when forecast values differ greatly.

b) If forecast values from different methods and different forecasters vary, choose the most appropriate forecast value to report; depending on the flood level, the authority approving the bulletin decides on selecting the forecast value.

5. Number and content of flood forecast bulletins

Implemented according to Decision No. 245/2006/QĐ-TTg dated October 27, 2006, issued by the Prime Minister, regarding the regulations on tropical depression, typhoon, and flood warnings;

6. The flood forecast bulletin must be completed at least five minutes before the official broadcast time.

7. Proofreading the bulletin:

a) The bulletin must include the name of the forecaster and the person approving the flood forecast bulletin; in the specific process, responsibilities must be clearly defined for the forecaster, the checker, and the supervisor;

b) For bulletins from units conducting forecasts under the National Hydrology, Meteorology, and Climate Center: the content of the bulletin must be consistent for the same forecast location and basin; if discrepancies are found, they must be resolved and a unified forecast value agreed upon; if no agreement can be reached, timely reports must be made to the competent authority for resolution before issuing the bulletin.

8. Monitoring and supervision

a) After issuing the forecast bulletin, the forecaster and the organization conducting the forecast must continue to monitor the flood situation and user feedback to promptly update as necessary.

b) The forecaster must strictly adhere to the assigned time and tasks during the shift, and at the end of the shift, must record the shift log and handover according to regulations.

c) The forecaster records the flood forecast results as required.

Article 5. Responsibilities of related organizations and individuals

1. Responsibilities of organizations and individuals under the Ministry of Natural Resources and Environment

a) National Hydro-meteorological Center

Direct and guide related subordinate organizations to establish procedures and flood forecasting plans based on the contents of this Circular and the river basin they are responsible for, their positions, and conditions regarding forecasting technology; conduct reviews, approvals, and inspections of implementation.

b) Central Hydro-meteorological Forecasting Center under the National Hydro-meteorological Center

Develop and report to the National Hydro-meteorological Center for approval of flood forecasting procedures within the assigned scope.

c) Regional Hydro-meteorological Stations under the National Hydro-meteorological Center

Develop and report to the National Hydro-meteorological Center for approval of flood forecasting procedures for the respective region; issue flood forecast bulletins for the respective region; direct, guide, and approve flood forecasting plans of provincial hydro-meteorological centers within the respective region.

d) Responsibilities of provincial hydro-meteorological centers under regional hydro-meteorological stations

Develop and report to regional hydro-meteorological stations for approval of flood forecasting plans for the respective area; issue local flood forecast bulletins according to authority.

2. Responsibilities of organizations and individuals permitted to carry out flood forecasting on the territory of Vietnam

Are responsible for the results of their flood forecasts; coordinate and promptly notify relevant agencies and units under the Ministry of Natural Resources and Environment about unusual situations discovered during the implementation of flood forecasting.

Article 6. Implementation Organization and Effectiveness

1. This Circular takes effect from September 15, 2010.

2. The Minister, Heads of Ministries equivalent to Ministries, Heads of Government Agencies, Chairpersons of Provincial People's Committees directly under the Central Government, and related organizations and individuals are responsible for implementing the provisions of this Circular.

3. The Meteorology, Hydrology and Climate Change Department is responsible for monitoring and inspecting the implementation of this Circular.

During implementation, if there are difficulties, organizations and individuals carrying out flood forecasting shall promptly reflect them to the Ministry of Natural Resources and Environment for research and amendment./.