Rainfall Runoff, Topography & Istanbul Seismic Ground Simulator

Rainfall runoff, topography and Istanbul Seismic & Ground (İBB)

The simulator provides two interactive modes selectable from the top bar:

1. Rainfall & Runoff Mode: Choose any point on the map, set an assumed rainfall rate and duration, then calculate. The simulator samples a 384 × 384 terrain grid around that location and routes modeled runoff downhill. Compare peak flow, contributing area, terrain adjustment, topography (elevation) and slope (%), and click any point to inspect its flow path and elevation profile.
2. Istanbul Seismic & Ground (İBB) Mode: Built from official Istanbul Metropolitan Municipality (İBB) & Boğaziçi University Kandilli Observatory studies (2007–2024) covering ~1,480 km² across 25 European Side districts and 599 neighborhoods at 250 m × 250 m resolution. Explore Settlement Suitability (UA / ÖA / UOA), Local Soil Class (Z1–Z4, ZB–ZE), Shear Wave Velocity (AVs30), Liquefaction (PL), Landslide Susceptibility (Fs), Geological Formation, PGA / PGV, and the Mw 7.5 Scenario Earthquake District & Neighborhood Loss Report Card.

How to use it

1. Select Rainfall & runoff or Istanbul Seismic & Ground (İBB) in the top mode switch.
2. In Rainfall & runoff mode, search for a street or address, set rainfall rate and duration, and click Calculate this location.
3. In Istanbul Seismic & Ground (İBB) mode, pick one of the 57 preset neighborhoods across 25 districts or click any grid cell on the map to inspect its geotechnical profile and Mw 7.5 building damage report card.

Data and attribution

• Coastlines and lakes: Natural Earth 1:50 million-scale data and OpenStreetMap water/coastline polygons.
• Elevation: Mapzen Terrain Tiles on AWS Open Data; see elevation attribution.
• Istanbul Seismic & Ground Data: İBB Directorate of Earthquake and Ground Research (2007–2024) — European Side Microzonation Report (2007), 1/25,000 Land-Use Geological Survey Report (2017), Boğaziçi Univ. Kandilli Observatory 25 District Earthquake Loss Estimation Booklets (2020), and İBB Geophysics & Landslide Reports (2024).
• Background map: © OpenStreetMap contributors.