Site Report
Pick any point on Earth and get its terrain, rocks, faults, earthquakes, climate, soil and rivers, screened for natural hazards, in one report.
One click gathers what a geologist or engineer needs to know about a place before the first field visit: coordinates in three systems, elevation, slope, aspect, relief and position in the landscape with two ground profiles; the mapped geological unit with its age, rocks and engineering character; the active faults around it with the largest magnitude they could produce and the nearest plate boundary; every instrumental earthquake of magnitude 4 and above since 1973 with rates and 50-year chances; the nearest Holocene volcano; 30-year climate normals with the Köppen–Geiger class and the aridity index; soil texture, pH and organic carbon by depth; and the nearest rivers with the height of the site above them. A screening matrix rates seven hazards and a checklist says what to test in the field. The whole report downloads as a PDF with a verification code.
Overview
The report is the desk study that comes before every site investigation, quarry licence, construction project or field trip, prepared in a minute instead of days. It brings together the data that the other Shandal tools treat in depth and reads them together: a steep slope on clay-rich rock under heavy rain, gypsum bedrock with shallow water, or a valley floor a few metres above a river are flagged because the combination matters more than each value alone.
Every figure follows the conventions of a technical report: the location map carries a neat line, a graticule, a north arrow, a graphic scale and a legend below it; the profiles state their vertical exaggeration; the climate diagram uses the Walter–Lieth scale. All figures download as PNG, JPG or PDF with the Shandal stamp, and the values as CSV or JSON.
What you enter · What you get
What you enter
- A point (map click, coordinates, place search or GPS)
- Project name and the person preparing the report
- Radius for earthquakes and faults (100, 150 or 250 km)
What you get
- Hazard screening matrix for seven hazards with the reasons
- Location map, ground profiles, earthquake and climate diagrams
- Terrain, geology, faults, earthquakes, climate, soil, rivers and volcano tables
- Field checklist and the Shandal tools to go deeper
- PDF report with a verification code; CSV and JSON data
How it works in the field
Method and equations
Terrain
Elevations of a 9 × 9 grid at 150 m spacing around the point and of two 6 km lines through it are read from a 90 m digital elevation model. Slope and aspect use Horn’s third-order finite difference on the central 3 × 3 window; the topographic position index (TPI) is the point minus the mean of the grid, and with slope classifies the point as crest, slope, flat or valley floor.
Geology and faults
The geological unit is taken from the most detailed map that covers the point; its description is searched for soluble (gypsum, anhydrite, salt), carbonate, clay-rich, loose and igneous rocks. Active faults within the radius are measured by point-to-line distance, and the largest magnitude each could produce is estimated from its mapped length with the surface-rupture relations of Wells & Coppersmith (1994).
Earthquakes
All events of magnitude 4 and above since 1973 within the radius are counted. Annual rates of M ≥ 5 and M ≥ 6 are the counts divided by the years of record, and the chance of at least one such event in 50 years follows the Poisson model.
Climate
Daily reanalysis of 1995–2024 gives monthly normals of temperature, precipitation and FAO-56 reference evapotranspiration (ET₀). The Köppen–Geiger class follows Peel, Finlayson & McMahon (2007); the aridity index P / ET₀ follows the UNEP classes.
Soil and water
Clay, sand, silt, pH, organic carbon, bulk density and coarse fragments are read from global soil predictions at 250 m for five depths to 1 m; the top 30 cm are averaged by layer thickness and classed on the USDA texture triangle. The nearest river, stream, canal and water body within 10 km are found from open map data, and the height of the site above the nearest one is the difference of the two ground elevations.
Hazard screening
Each hazard adds simple scores from the factors above (for example: fault distance < 5 / 20 / 50 km, M ≥ 5 per decade ≥ 3 / 1 / 0.3, plate boundary < 100 / 300 km for shaking; slope classes, weak rock, rain and shaking for landslides; flat ground, valley floor, distance and height above water and daily rain for floods). The sums are read as low, moderate, high or very high. The weights are expert rules, stated here so that the user can judge each result.
Accuracy and error limits
- Elevation is accurate to about ±5–10 m vertically (more in steep or forested ground and in cities); slope from a 150 m window underestimates short steep slopes and cliffs. Geological boundaries on regional maps can be 200–1000 m out and small units are not shown. Fault traces are generalised (positions ±1–2 km) and blind faults are missing; the magnitude from length is ±0.3–0.5. Plate boundaries are drawn as single lines, while in the Zagros and other collision belts the real boundary is a deforming zone up to a few hundred kilometres wide.
- The earthquake record is complete for M ≥ 4.5 since about 1973 in most regions but not for M 4 before about 1990; 50 years of record may miss rare large earthquakes, so rates are lower bounds for long return periods. Climate normals come from a 10–25 km grid and smooth out mountain and valley effects (rainfall ±15–30 %). Soil values are predictions with typical errors of ±8–12 % for clay and sand and ±0.4 for pH, and are missing in built-up areas.
- The hazard levels are a screening, not a design: they show where to look and which tests to order. To reduce the error, confirm the rock and soil in the field, use trial pits and boreholes with laboratory tests, measure shear-wave velocity for the seismic site class, use the national seismic code or a site-specific hazard study, and ask local people about past floods and ground cracks.
Who uses it
Standards and references
- Horn, B.K.P. (1981). Hill shading and the reflectance map. Proceedings of the IEEE, 69, 14–47.
- Weiss, A. (2001). Topographic position and landforms analysis. ESRI User Conference, San Diego.
- Wells, D.L. & Coppersmith, K.J. (1994). New empirical relationships among magnitude, rupture length, rupture width, rupture area and surface displacement. Bulletin of the Seismological Society of America, 84, 974–1002.
- Styron, R. & Pagani, M. (2020). The GEM Global Active Faults Database. Earthquake Spectra, 36, 160–180.
- Bird, P. (2003). An updated digital model of plate boundaries. Geochemistry, Geophysics, Geosystems, 4, 1027.
- U.S. Geological Survey, ANSS Comprehensive Earthquake Catalog (ComCat).
- Global Volcanism Program (2024). Volcanoes of the World, v. 5. Smithsonian Institution.
- Peel, M.C., Finlayson, B.L. & McMahon, T.A. (2007). Updated world map of the Köppen–Geiger climate classification. Hydrology and Earth System Sciences, 11, 1633–1644.
- Allen, R.G., Pereira, L.S., Raes, D. & Smith, M. (1998). Crop evapotranspiration. FAO Irrigation and Drainage Paper 56.
- Hersbach, H. et al. (2020). The ERA5 global reanalysis. Quarterly Journal of the Royal Meteorological Society, 146, 1999–2049.
- Poggio, L., de Sousa, L.M., Batjes, N.H. et al. (2021). SoilGrids 2.0. SOIL, 7, 217–240.
- Walter, H. & Lieth, H. (1960). Klimadiagramm-Weltatlas. Fischer, Jena.
- UNEP (1992). World Atlas of Desertification. Edward Arnold, London.
- Copernicus DEM GLO-90, European Space Agency.
At a glance
- Category
- Field geology
- Runs on
- Phone, tablet and desktop browser
- Export
- Full report as PDF with a verification code; location map, profiles, earthquake and climate diagrams as PNG, JPG and PDF; values as CSV and JSON
- Access
- Free
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