Geohazard assessment
Identification of landslides, groundwater flooding, erosion, collapsible and swelling soils, with mitigation recommendations.
Licensed service · EL-845/2026
On some sites the main risk is not soil bearing capacity but geological processes that develop over time: slope movement, rising groundwater, collapse of soils on wetting. Identifying them before construction allows protective measures to be built into the design in good time.
What geohazards are
Geohazards are natural or human-induced processes that can damage buildings and structures and restrict land use. Some are obvious (tension cracks on a slope, gullies); others are revealed only by investigation: soils that collapse on wetting, a gradual rise in groundwater, dissolution of salts.
The assessment aims to establish whether a process is present, how far it has developed and how construction may change it. For example, excavating a foundation pit at the toe of a slope, or irrigating the site, can reactivate a slope that appears stable.
Processes assessed
- Landslides — downslope movement of ground; on steep slopes and where clay layers are saturated.
- Groundwater flooding — rising groundwater wetting basements and foundation soils.
- Erosion — removal of soil by surface water, gully growth, lateral erosion of riverbanks.
- Coastal abrasion — wave erosion of the sea shore.
- Debris flows (mudflows) — for sites near river channels in mountain and foothill areas.
- Problematic soils — collapsible, swelling, saline soils and made ground.
- Seismic effects — amplification of ground motion by site conditions, potential liquefaction of loose saturated sands during earthquakes.
- Mud volcanism — for sites close to mud volcano structures on Absheron and in Shirvan.
How construction can change these processes
The assessment considers not only the current state of the site but also the conditions that will exist after construction. A foundation pit undercuts the toe of a slope and reduces its stability. Paving and buildings alter natural stormwater runoff, and concentrated flow can create gullies. Leaks from water and sewer networks and irrigation of landscaping raise groundwater over the years, wetting collapsible and saline soils. Recommendations in the report therefore cover both the construction period and the operation of the building.
When it is required
- for construction on slopes, near gully edges, on riverbanks or the sea shore;
- where cracking, tilting or damp is seen on site or in neighbouring buildings;
- in areas with shallow or rising groundwater;
- where loess-like, saline soils or made ground are likely;
- for linear structures crossing complex terrain;
- for important and multi-storey projects.
Scope of work
| Activity | Purpose | Output |
|---|---|---|
| Review of archive data and old topographic plans | identify past occurrences and changes in terrain | preliminary hazard zoning |
| Reconnaissance survey | record tension cracks, tilted trees, seepage points, building distress | map of features and photographs |
| Drilling and probing | locate weak layers, the slip surface and groundwater | cross-sections, groundwater levels |
| Geophysical surveys | trace the landslide body, voids and wet zones across the site | geophysical sections |
| Laboratory testing | determine collapsibility, swelling potential, salt content, shear strength | parameters for analysis |
| Slope stability analysis | check stability in existing and post-construction conditions | analysis results and mitigation recommendations |
For groundwater-related risks we offer flooding risk and drainage recommendations, and for tracking movement over time, deformation and settlement monitoring.
Project stages
- Preparation. Collection of archive data and old plans, preparation of the work programme.
- Field work. Walkover, boreholes, probing, geophysical profiles, groundwater measurements.
- Laboratory. Tests on problematic soils, water chemical analysis.
- Office processing. Description of processes, stability analyses, hazard zoning.
- Handover. Results are delivered as a section of the engineering geological report or as a separate assessment.
Equipment used
- drilling and probing rigs — to investigate the ground profile;
- electrical resistivity and seismic survey equipment — to trace landslide bodies and wet zones;
- GNSS receivers, total stations, UAVs — to survey terrain and signs of movement;
- laboratory equipment — for shear, collapsibility and swelling tests.
Deliverables
- description of identified processes and their stage of development;
- hazard zoning plan;
- slope stability analysis results (where required);
- mitigation recommendations: drainage, surface water control, retaining structures, foundation solutions, monitoring.
Protective structures are designed by the design consultant, for whom the report provides input data. Documents are delivered as PDF and in hard copy, drawings in DWG on request.
Timeline
- site size and type of process;
- number of boreholes and geophysical profiles;
- whether stability analyses are required.
Information we need from you
- site address and topographic plan (if available);
- photographs of any observed signs;
- details of planned construction and earthworks.
What affects the price
- site size and terrain complexity;
- volume of drilling, probing and geophysics;
- scope of laboratory testing and need for analyses.
Indicative rates are on the prices page; for an exact estimate, request a quote.
