Groundwater potential mapping and assessment

What is a groundwater potential map?

It is a map that ranks every part of a site by its chances of holding usable groundwater, from very low to very high. Hydrogeologists draw one before a drilling campaign to focus effort on the best zones.

Made by hand in a GIS with many data layers, it takes days of work. BhdBlue automates it and delivers it in a few minutes.

The satellite data used

• Copernicus DEM 30 m: elevation, slope, flow accumulation and the topographic wetness index (TWI).
• Sentinel-2: the vegetation index (NDVI) in the dry season, when green vegetation betrays water; ESA WorldCover for land cover.
• CHIRPS: 10-year average rainfall, the source of recharge.
• SoilGrids: soil texture, which controls infiltration.
• Stream network and drainage density, from the terrain and OpenStreetMap.
• Lineaments (faults and fractures) extracted automatically from the terrain, plus the geological map in Morocco.

The method: AHP multi-criteria analysis

Each layer is turned into a score from 0 to 1 according to its known effect on groundwater. The Analytic Hierarchy Process (AHP), widely used in published groundwater potential studies, then weights each criterion, following the ranking of importance that recurs in published studies of hard-rock and sedimentary terrains.

The weighted sum gives the potential map. To measure reliability, BhdBlue repeats the calculation many times with varied weights (Monte Carlo): a zone that stays high in nearly every test is a solid result.

What the map gives you

• See at a glance the areas to favour and those to avoid.
• Choose the best drilling spots, delivered with GPS coordinates.
• See which criterion weighs most at each proposed spot and the direction of surface water flow, derived from the terrain.
• Share a clear PDF report, in French and Arabic, with a driller, a consultancy or a funder.

Method and limits

Each analysis combines satellite-derived indicators (terrain, vegetation, drainage, lineaments), geological and climate datasets, and a multi-criteria GIS analysis (AHP) that estimates groundwater potential. It is neither a field measurement nor a geophysical survey. See the detailed method

• The 30 m grid is the spatial resolution of the analysis, not a guaranteed accuracy for a drilling spot.
• BhdBlue does not estimate the depth of the water table, its yield or volume, water salinity, or a probability of drilling success.
• The flow direction shown is that of surface water, derived from the terrain, not of the aquifer.
• Before a major borehole, have the spot confirmed by a hydrogeologist or an on-site geophysical survey.