Circular No. 11/2014/TT-BTNMT on technical procedures for mapping groundwater quality at a scale of 1:200,000

CIRCULAR
Technical regulations for creating groundwater quality maps at a scale of 1:200,000

 Based on the Law on Water Resources No. 17/2012/QH13 dated June 21, 2012;

Pursuant to Decree No. 21/2013/NĐ-CP dated March 4, 2013, promulgated by the Government, stipulating the functions, tasks, powers, and organizational structure of the Ministry of Natural Resources and Environment;

XAt the proposal of the Director of the National Water Resources Management Department; the General Director of the National Center for Water Resources Planning and Investigation; the Heads of the Science and Technology Department and the Legal Affairs Department;

BThe Minister of Natural Resources and Environment issues this Circular on technical regulations for creating groundwater quality maps at a scale of 1:200,000.

PART I
GENERAL PROVISIONS

Article 1. Scope of Regulation and Applicability

Article 1. This Circular specifies in detail the contents and technical procedures for creating groundwater quality maps and products of such maps at a scale of 1:200,000.

Article 2. This Circular applies to state management agencies for water resources, organizations, and individuals who undertake the creation of groundwater quality maps at a scale of 1:200,000.

Article 3. Purpose of Creating Groundwater Quality Maps at a Scale of 1:200,000

Point 1. To reflect the results of groundwater resource investigation and assessment work at a scale of 1:200,000 or larger scales, and other related studies on water quality.

Point 2. To serve state management of groundwater resources within economic and social regions and inter-provincial river basins.

Point 3. To provide a basis for planning groundwater resources, developing economic and social regions, and large river basins.

Point 4. To serve the needs of exploiting and using information for various sectors, localities, organizations, and individuals involved in groundwater exploitation and utilization activities.

Article 4. Base Maps for Creating Groundwater Quality Maps at a Scale of 1:200,000

Point 1. Groundwater quality maps at a scale of 1:200,000 are established based on topographic and hydrogeological base maps at the same scale or larger scales.

Point 2. Topographic base maps are topographic maps at a scale of 1:200,000 (VN-2000 coordinate system) or larger scale maps adjusted to a scale of 1:200,000.

Point 3. Hydrogeological base maps are hydrogeological maps at a scale of 1:200,000 (VN-2000 coordinate system) or larger scale maps adjusted to a scale of 1:200,000.

Point 4. In cases where there are no existing hydrogeological maps in the research area, it is necessary to conduct surveys and create specialized hydrogeological maps containing sufficient information to support the creation of groundwater quality maps.

Article 5. Mathematical Basis of Groundwater Quality Maps at a Scale of 1:200,000

Point 1. Groundwater quality maps at a scale of 1:200,000 are established in the VN-2000 National Geodetic Reference System with the following characteristics: Global Ellipsoid WGS-84 suitable for Vietnam's territory; International UTM Plane Coordinate System; Zone 6.

Point 2. The projection systems and central meridians shall be implemented according to Circular No. 973/2001/TT-TCĐC dated June 20, 2001, issued by the Land Administration General Department guiding the application of the VN-2000 National Geodetic Reference System.

Article 6. Technical Inspection and Product Acceptance Work

Technical inspection and product acceptance work shall be carried out in accordance with current regulations of the Ministry of Natural Resources and Environment.

Article 7. Types of Products

Point 1. Products of groundwater quality maps at a scale of 1:200,000 include:

a) Groundwater quality maps at a scale of 1:200,000 and cross-sections;

b) Groundwater quality maps for important aquifers at a scale of 1:500,000;

c) Supplementary data for map creation: Chemical composition and groundwater quality statistics book;

d) Special reports: Characteristics of groundwater quality.

Point 2. Products are published in paper and digital formats.

Chapter II
CONTENTS OF GROUNDWATER QUALITY MAPS AT A SCALE OF 1:200,000

Article 7. Basic elements

1. Topographic basic elements On the groundwater quality map at a scale of 1:200,000, the following topographic basic elements must be ensured to be represented:

a) Mathematical base layer: Map name, grid frame, elements outside the frame;

b) Topography layer: Contour lines, points and height values;

c) Hydrographic layer: Rivers, streams, lakes, ponds, canals and their names;

d) Transportation layer: Roads, railways, bridges and their names;

đ) Population layer: Concentrated residential areas, clusters of residents;

e) Administrative layer: For district level including the headquarters of district people's committees, city districts under provincial jurisdiction and for province level including the headquarters of provincial people's committees, centrally governed cities; names of administrative units: district, county, city district under provincial jurisdiction, province, centrally governed city;

g) Boundary layer: District, county, city district under provincial jurisdiction, province, centrally governed city boundaries, watershed limits, border lines.

The details of topographic elements must comply with the provisions of geographic information standards issued by the Ministry of Natural Resources and Environment. Topographic basic elements may be reduced by 15% to 25% to ensure priority representation of groundwater quality elements.

2. Hydrogeological basic elements:

a) Distribution area of water-bearing and non-water-bearing objects, including: Water-bearing structures, rock formations containing water or large complex water-bearing systems and structures, formations, complexes not containing water;

b) Faults predicted to contain water.

Article 8. Specialized elements

Specialized elements depicted on the groundwater quality map at a scale of 1:200,000 include:

1. Water quality for various uses.

2. Chemical composition of water at locations where analysis results are available.

3. Saltwater intrusion zone.

Chapter III
TECHNICAL REPRESENTATION OF GROUNDWATER QUALITY MAP AT A SCALE OF 1:200,000

Article 9. Principles for representing the groundwater quality map at a scale of 1:200,000

The groundwater quality map at a scale of 1:200,000 must reflect the contents of research results conducted through surveys and assessments of groundwater resources at a scale of 1:200,000. The contents and information depicted on the groundwater quality map at a scale of 1:200,000 are based on the following principles:

1. Aquifer units divided by layers, complexes, water-bearing structures, and non-water-bearing formations, represented by information such as the name of the complex, layer or water-bearing structure, distribution area, distribution boundary.

2. The distribution area of water with different total mineralization suitable for various uses is represented by color.

3. Total mineralization (M) of layers, complexes, and water-bearing structures at points with analytical results is shown at representative points; salt boundaries of layers, complexes, and water-bearing structures covered are shown by lines of equal value M=1g/l.

4. Chemical composition: Represented by the dominant symbol of major ions at each sampling investigation point and Kurlov formula on cross-sections.

5. Groundwater survey points such as drill holes, dug wells, surface water points are shown by symbols accompanied by numbers and layer, complex or water-bearing structure symbols surveyed.

6. Faults predicted to contain water on the groundwater quality map at a scale of 1:200,000 are represented by line form.

7. Cross-sections: Cross-sections are established along characteristic directions such as perpendicular to structural orientation, along typical groundwater flow direction. The number of cross-section lines is selected according to the region where the map is being prepared.

Article 10. Form of the Groundwater Quality Map at Scale 1:200,000

1. The name of the map, frame, and label shall be displayed according to the model prescribed in Appendix 3 attached hereto.

2. In cases where the map consists of multiple pieces, a piece assembly diagram shall be shown in the lower right corner of the map frame.

3. The legend of the map is usually placed on the right side of the map frame, while cross-sections are placed below the map frame. In some cases, the legend may be placed within the map frame at an appropriate location or below the map frame.

4. Size of objects to be depicted

On the groundwater quality map at scale 1:200,000, objects depicted as areas must have a minimum actual width of 400 meters; objects depicted as lines must have an actual length of at least 2,000 meters.

Article 11. Content Depicted on the Groundwater Quality Map at Scale 1:200,000

1. Aquifer systems and water-bearing structures, non-water-bearing layers:

a) Boundaries of primary aquifer systems and water-bearing structures are represented by continuous purple lines with a thickness of 0.4 mm, and distribution boundaries of covered aquifer systems and water-bearing structures are indicated by dashed purple lines with a thickness of 0.7 mm, pointing towards the distribution area, accompanied by symbols for aquifer systems and water-bearing structures.

b) Non-permeable layers or geological formations that do not contain water are shown as brown areas.

2. Distribution areas of water with different total mineralization levels:

a) Total mineralization level M (g/l) scale:

- Fresh water: M < 1.0;

- Brackish and saline water: M ≥ 1.0.

b) Representation of total mineralization levels: For primary aquifer systems and water-bearing structures on the map and cross-sections, total mineralization will be represented by color according to the M value scale:

- Areas of underground water with M values less than 1.0 g/l are shown in yellow;

- Areas of underground water with M values equal to or greater than 1.0 g/l are shown in orange.

c) Boundaries of areas with different total mineralization levels are represented by continuous green lines with a thickness of 0.7 mm.

3. Total mineralization of covered aquifer systems and water-bearing structures: The total mineralization of covered aquifer systems and water-bearing structures will be represented in two forms:

a) The boundary of salinity M = 1 g/l is shown by a dashed orange line with a thickness of 0.7 mm, accompanied by symbols for aquifer systems or water-bearing structures, with corresponding number of dashes for each layer, aquifer system, or water-bearing structure, the direction of the dashes pointing towards the area with M values greater than 1 g/l;

b) The range of M values for layers, aquifer systems, or water-bearing structures is shown by red hatching in columns at representative points.

4. Chemical composition: The chemical composition of water at drilling holes, dug wells, and exposed sources is shown by symbols representing the dominant ion concentrations of major elements and Kurlov formulas on cross-sections.

5. Groundwater survey points:

a) Drilling holes: Represented by black circles with a diameter of 3 mm, accompanied by information: drilling hole number, layer symbol, aquifer system or water-bearing structure being surveyed, total mineralization, and chemical composition;

b) Dug wells: Represented by black squares with sides of 3 mm, accompanied by information: number, layer symbol, aquifer system or water-bearing structure being surveyed, total mineralization, and chemical composition;

c) Exposed sources: Represented by black circles with a diameter of 3 mm, with arrows pointing upwards for upward flowing points and downwards for downward flowing points, accompanied by information: exposed source number, layer symbol, aquifer system or water-bearing structure being surveyed, total mineralization, and chemical composition.

6. Faults: Only faults predicted to contain water are shown by dashed red lines with dots (.) and a thickness of 0.7 mm.

7. Cross-sections: On cross-sections, the distribution of layers, aquifer systems, or water-bearing structures and non-permeable layers is shown; areas of water with different total mineralization levels within each layer, aquifer system, or water-bearing structure; chemical composition and Kurlov formulas at drilling holes.

8. Specifications for depicting content and symbols on the map and legends are detailed in Appendices 1 and 2 attached hereto.

1. The Minister, Heads of Ministries equivalent to Ministries, agencies under the Government, Chairpersons of People's Committees of provinces and centrally governed cities, Director of the National Water Resources Management Agency, General Director of the National Center for Water Resources Planning and Investigation, Heads of units directly under the Ministry, and related organizations and individuals are responsible for implementing this Circular.

Chapter IV
IMPLEMENTING PROVISIONS

Article 12. Implementation Organization

2. The National Water Resources Management Agency is responsible for guiding and inspecting the implementation of this Circular.

1. This Circular takes effect from April 7, 2014.

Article 13. Effective Date

2. During the implementation process, if there are any difficulties, relevant agencies, organizations, and individuals are requested to promptly report to the Ministry of Natural Resources and Environment for research, amendment, and supplementation./.

2. During the implementation process, if there are any difficulties, it is recommended that agencies, organizations, and individuals promptly reflect them to the Ministry of Natural Resources and Environment for study, amendment, and supplementation./.