PythiasWater — User GuidePythiasWater is a map-based dashboard showing daily environmental layers (rainfall, soil moisture, solar power potential, and seasonal flood risk for India), plus country-level groundwater data and region statistics. It's free to use, with no account required.
Informational only. Data shown is derived from third-party satellite and reanalysis sources. It is not warranted for accuracy or completeness and must not be used for safety-critical, commercial, or regulatory decisions. See the credits panel in the app for full data attribution.
1. Switching language
PythiasWater is available in English (EN) and French (FR). Click the EN/FR buttons in the top-right corner of the app to switch. Your choice is remembered on that device for next time — you won't need to switch again unless you use a different browser or device.
2. The map
The map opens centered on the world at low zoom. Use your mouse/trackpad to pan and scroll to zoom, or the +/− buttons in the top-right.
Layers panel
On the left, the Layers panel lists the available daily environmental layers:
| Layer | What it shows |
|---|---|
| Rainfall | Daily precipitation |
| Soil Moisture | Water table proxy (soil moisture) |
| Solar Power | Solar irradiance |
| Flood Risk (India) | Seasonal flood risk, India only |
For each layer:
- Checkbox — turns the layer on/off on the map.
- Date dropdown — pick which day's data to display (defaults to the most recent date available). Each layer updates independently — you can, for example, view today's rainfall alongside last week's solar data.
- Hover over the layer name — a tooltip shows the data source and how often it's naturally updated (its “cadence”) and the date currently selected. Some layers (like vegetation-derived ones, if added later) aren't updated daily, so this tells you how fresh what you're looking at really is.
When a layer is turned on, a legend appears on the map itself, showing the color scale and units for that layer.
Draw a region for statistics
Click Draw region for stats, then click on the map to place the corners of a polygon around the area you're interested in (double-click or click the first point again to close the shape).
Once drawn, a stats panel appears with:
- Region area (km²)
- Number of cities and their combined named population
- Estimated total population and mean population density
- Any known borewells and their average depth to water, if the region has groundwater coverage (see below)
- Which daily layers overlap the region and at what threshold level
- The top cities in the region by population
You can redraw a new region at any time by clicking Draw region for stats again — this replaces the current shape.
Downloading a PDF report
Once stats are shown, a Download report (PDF) button appears. It generates a PDF with the same statistics plus full tables of every city, borewell, and aquifer found in the region (not just the top few shown on screen), along with data attribution and the informational-use disclaimer.
3. Groundwater by country
Below the layers panel, the Groundwater (by country) dropdown lets you pick a country to see its known aquifers and borewells on the map. Only countries with loaded groundwater data are selectable — others are shown grayed out with “(no data)”.
Selecting a country:
- Zooms/fits the map to that country's groundwater data.
- Colors aquifer polygons and well markers by depth to water (white = shallow, purple = deep). A gray fill/marker means no depth reading is available for that feature.
- Click any well marker to see its name, depth to water, and the date of that measurement (if known).
A legend for the depth-to-water color scale appears on the map while a country is selected. Selecting a different country (or the blank “Select a country…” option) clears the previous country's layers.
4. Data sources & disclaimer
Scroll to the bottom of the controls panel (or check the Credits section shown in the app) for the full list of data sources — NASA (GPM IMERG, GLDAS, SEDAC GPWv4), Copernicus/ECMWF (CAMS), GeoNames, and EC JRC/Google's surface water dataset (used for the India flood-risk layer) — along with required attribution notices and the informational disclaimer.
5. Troubleshooting
The app looks out of date, or a feature seems to be
missing. Your browser may be showing a cached copy of the
page. Try a hard refresh: Ctrl+Shift+R
(Windows/Linux) or Cmd+Shift+R (Mac), or open the
site in a private/incognito window.
“Couldn't load country list” or an error loading groundwater/stats data. This usually means a network request failed. Reload the page; if it persists, try again later.
Nothing happens when I click “Draw region for stats.” Make sure you're clicking directly on the map to place polygon points, and double-click (or click your starting point again) to finish the shape.