Content of groundwater resource map at 1:200,000 scale in Vietnam

Content of groundwater resource map at 1:200,000 scale in Vietnam (Illustration)

Article 10 of Circular 17/2013/TT-BTNMT stipulates the technical specifications for illustrating the content of the groundwater resource map at a scale of 1:200,000 as follows:

The groundwater resource map at a 1:200,000 scale must reflect the content of research results conducted to survey and assess groundwater resources at the same scale. The content and information represented on the groundwater resource map at a 1:200,000 scale must adhere to the following principles:

- Aquifer and non-aquifer objects are represented according to distribution boundaries;- Natural dynamic reserves are represented in region form;- Evaluated groundwater reserves are represented through approved reserve levels, illustrated by frame and reserve value of the levels;- Groundwater quality is represented in line and point form;- Artificial structures such as hydrological stations, boreholes, dug wells, and groundwater outlaws are represented in point form;- Predicted fault lines containing water on the groundwater resource map at a 1:200,000 scale are represented by thick red lines.- For the dimension of the represented object: On the groundwater resource map at a 1:200,000 scale, objects represented in region form must have an actual size of 4km² or larger; objects represented in line form must have an actual length of 2,000m or longer; on the cross-section, the object represented must have an actual thickness of 20m or greater, extending at least 2,000m.

Furthermore, the technical specifications for illustrating the map are as follows:

- Aquifer structures, aquifer-forming soils and rocks, or large aquifer complexes, and structures, formations, and complexes that do not hold water:

- Each complex and aquifer layer are represented by information: existence form, complex name, distribution area;- Boundaries of aquifers, aquifer layers on the surface are represented by a 0.4mm solid purple line; for covered aquifer layers, they are represented by a 0.4mm solid purple line with hatch towards the distributing aquifer, layer;- Non-aquifer structures, formations, and complexes are represented by brown regions.

- Natural dynamic reserves:- Natural dynamic reserves of groundwater are determined by the groundwater flow module value, divided into 3 scales: < 2 l/s.km², 2 ÷ 6 l/s.km², > 6 l/s.km²;- Groundwater flow module values in pore water and fracture water are differentiated by color: sky blue for pore water, green for fracture water. The overall color represents the module value: dark color corresponds to a larger module value, light color corresponds to a smaller module value.

- Evaluated groundwater reserves are represented by a 1mm black frame and black numbers and letters indicating reserve levels and evaluated aquifer unit symbols;

- Groundwater quality: Groundwater quality is represented through main ions (represented by research points) and total dissolved solids (TDS) values.

- Groundwater research points: hydrological station, borehole, dug well, spring.

- Predicted fault lines containing water are illustrated by a 0.7mm solid red line.

- The cross-section of the groundwater resource map represents research aquifer units in depth. The cross-section line must be marked on the map by a 0.7mm black line. Each aquifer layer shows reserve information and water quality. Additionally, it represents the location and information of typical research structures.

For further details, refer to Circular 17/2013/TT-BTNMT, effective from August 5, 2013.

Le Vy

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