Why wait for disaster to strike? With free global datasets and accessible tools, nonprofits can build or improve community-facing flood early-warning services without large budgets. This post explains five practical steps, tools to start with, and how to turn forecasts into actionable community alerts.
Introduction
Floods are the world’s most common and costly natural hazard. For community-focused nonprofits, timely warnings can mean the difference between safe evacuation and catastrophic loss. Today, several open systems — from the EU’s Copernicus services to NASA and the Global Flood Awareness System — provide reliable, near-real-time data that organizations can use for local early-warning and preparedness work.
What we’ll cover
- A short primer on key open sources (what they offer)
- Five practical steps your program can follow this week
- Tools and templates to convert data into community alerts
- What this means for nonprofits
Key open sources to know
- GloFAS (Global Flood Awareness System) — regional and global flood forecasts and ensemble river discharge forecasts: https://www.globalfloods.eu/
- Copernicus Emergency Management Service (CEMS) — emergency mapping, flood layers, satellite-derived products: https://emergency.copernicus.eu/
- GDACS (Global Disaster Alert and Coordination System) — alerts and impact coordination for floods and other hazards: https://www.gdacs.org/
- NASA Disasters program — remote sensing data and applied products for rapid response: https://disasters.nasa.gov/
- Google Earth Engine — cloud processing for satellite imagery and change detection: https://earthengine.google.com/
- GFDRR (World Bank) resources and guidance on flood risk and early warning: https://www.gfdrr.org/
Step-by-step: From data to community alerts
Step 1 — Identify the forecast layer that fits your geography
Start by matching scale and lead time to your needs. GloFAS gives continental-to-local river-discharge forecasts with several days' lead time; Copernicus EMS and satellite imagery detect actual inundation after an event. Use GloFAS for anticipatory action and satellite-derived flood extents for verification and damage assessment.
Step 2 — Build a simple ingestion pipeline (no heavy engineering required)
You don’t need a data science team to start. Two low-effort approaches:
- Manual pull: Download GloFAS ensemble forecast maps or Copernicus flood layers and convert them into local maps for your community partners.
- Lightweight automation: Use Google Earth Engine or open scripts that pull forecasts and generate threshold-based alerts. Earth Engine has public datasets and user-friendly APIs for non-expert teams.
Tool suggestions: Google Earth Engine (https://earthengine.google.com/), public GloFAS datasets (https://www.globalfloods.eu/), and GDACS alert feeds (https://www.gdacs.org/).
Step 3 — Translate forecast signals into local triggers
A forecast is only useful if it maps to action. Work with local partners to define clear triggers (e.g., predicted river discharge exceeding X cubic meters/second or a 5-day flood probability > 60%). Create a simple matrix: forecast level → community action (monitor, pre-position supplies, evacuate).
Step 4 — Choose delivery channels your community trusts
SMS, community radio, local leaders, and WhatsApp groups remain highly effective. Integrate technical alerts into culturally appropriate messages: include location, expected timing, recommended action, and where to get help. Test messages in peace time with community volunteers.
Step 5 — Verify, iterate, and document
After each event or drill, compare observed flood extent (Copernicus or NASA imagery) with what the forecast predicted. Note false positives and misses, then adjust trigger thresholds and messaging. Maintain a simple log of events, decisions, and outcomes to build institutional memory.
Pull-quote
"Open forecast data is powerful — but only when matched to clear local triggers and trusted delivery channels."
Practical templates and starter scripts
- Threshold matrix template (example): forecast probability bands mapped to actions (Monitor / Prepare / Evacuate).
- Basic Earth Engine script pattern: ingest GloFAS layers, clip to your watershed, and compute exceedance probabilities (many public examples exist in the Earth Engine repository).
- SMS/WhatsApp checklists: short, action-focused messages and escalation paths.
What this means for nonprofits
- Lower barrier to entry: You can begin with manual workflows and scale to automation as capacity grows.
- Focus on people: Technical accuracy matters, but the biggest gains come from localized triggers and trusted communication.
- Partnerships amplify impact: Work with meteorological services, local authorities, and other NGOs to validate triggers and share responsibilities.
Call to action
Start small this month: pick one river reach or community, subscribe to the relevant GloFAS/GDACS feeds, and run a tabletop drill using the threshold matrix. If you’d like a starter Earth Engine script or the threshold matrix template from HorizonAid, contact us or subscribe to updates.
References
- GloFAS — Global Flood Awareness System: https://www.globalfloods.eu/
- Copernicus Emergency Management Service (CEMS): https://emergency.copernicus.eu/
- GDACS — Global Disaster Alert and Coordination System: https://www.gdacs.org/
- NASA Disasters: https://disasters.nasa.gov/
- Google Earth Engine: https://earthengine.google.com/
- G FDRR — Global Facility for Disaster Reduction and Recovery: https://www.gfdrr.org/