What Makes Our Data Unique
Most preparedness sites focus on one dimension — planting calendars, hazard maps, or foraging guides. We combine 10+ free public data sources into a single location-specific profile covering water, food, energy, hazards, infrastructure, and wildlife. No other tool gives you a composite survival picture for your exact zip code.
Every score below is computed from real data — no opinions, no sponsored rankings. We publish our formulas so you can verify and cite them.
Survival Score (0–100)
The headline number on every location page. It answers: “How well-suited is this location for long-term self-reliance?”
Components & Weights
- Food Independence (30%) — crops, foraging, hunting/fishing capacity
- Water Security (20%) — rainfall, proximity to water sources, rainwater collection potential
- Disaster Resilience (20%) — FEMA hazard scores inverted
- Energy Potential (15%) — solar irradiance, wind speed
- Infrastructure (15%) — supply chain density, evacuation options, comms
Days of Autonomy (3–180 days)
Estimates how many days a household could sustain itself without external supply chains, based on local resources.
Calculation Factors
- Water — Rainfall + nearest freshwater distance
- Food — Crop growing days + edible species count + game availability
- Energy — Solar potential + wind potential
- Supply chain buffer — Supermarket density, people-per-store ratio
The score caps at 180 days. Locations scoring above 90 days have strong autonomous potential; below 14 days indicates high dependency on external supply chains.
Food Independence Score
Measures a location's capacity to produce and forage food year-round.
- Growing capacity — Number of viable crops × frost-free days
- Foraging — Edible plant species count for the region
- Game — Huntable mammals, birds, and fishable species
- Livestock viability — Climate suitability for poultry, goats, rabbits, etc.
Homestead Viability Score
Evaluates how suitable a location is for establishing a productive homestead.
- Soil quality — pH, organic carbon, texture from SoilGrids
- Water access — Rainfall, groundwater depth, surface water proximity
- Climate — USDA zone, frost-free days, temperature extremes
- Regulatory — Building codes, rainwater collection laws, agricultural zoning
Disaster Resilience Score
Derived from FEMA's National Risk Index, which assesses 18 natural hazards at the county level. We invert the risk scores so higher values mean greater safety.
Hazards assessed include: earthquakes, hurricanes, tornadoes, flooding, wildfire, winter storms, drought, hail, heat waves, volcanic activity, tsunamis, landslides, ice storms, strong wind, lightning, avalanche, coastal flooding, and cold waves.
Supply Chain Vulnerability
Measures how dependent a location is on external supply chains and how quickly disruptions would affect residents.
- People-per-supermarket ratio — Higher ratio means faster shelf depletion during crises
- Fuel station density — Access to transportation fuel within 20km
- Hardware/supply stores — Access to repair materials and survival gear
- Infrastructure density — Overall commercial infrastructure within range
Communication Resilience
Evaluates the robustness of communication infrastructure — critical for receiving emergency alerts and coordinating during disasters.
- Cell tower density — Towers within 30km radius from OpenStreetMap
- Redundancy — Multiple towers mean signal survives if some are damaged
- Score bands — Excellent (>50 towers), Good (20–50), Fair (5–20), Poor (<5)
Data Sources & Attribution
All data comes from free, public sources. No proprietary datasets, no paid APIs.
| Source | What We Use It For | Update Frequency |
|---|---|---|
| USDA Hardiness Zones | Growing season, crop viability, planting calendars | Updated when USDA revises (last: 2023) |
| FEMA National Risk Index | Natural hazard scores, disaster resilience ratings | Annual updates |
| NOAA Climate Normals | Frost dates, precipitation, temperature ranges | 30-year normals, updated every 10 years |
| SoilGrids (ISRIC) | Soil composition, pH, organic carbon, texture | Continuous updates |
| OpenStreetMap / Overpass API | Infrastructure, evacuation routes, supply chain, cell towers | Community-maintained, near real-time |
| US Census Bureau | Population density, urbanization classification | Decennial census + annual estimates |
| NASA POWER | Solar irradiance, wind speed for energy potential | Monthly updates |
| USGS National Water Info | Nearest water bodies, watershed data | Continuous monitoring |
| Know Your Ground Flora DB | 184 plants (edible, medicinal, poisonous) by region | Curated, updated quarterly |
| Know Your Ground Fauna DB | 116 animals (game, fish, birds, dangerous) by region | Curated, updated quarterly |
| Know Your Ground Crops DB | 43 crops with zone-aware planting windows and calorie data | Curated, updated quarterly |