Source hierarchy

For present-day technical claims we prefer current primary or authoritative sources: WHO/UNICEF and JMP for WASH definitions and monitoring systems; USGS for groundwater measurement practice; FAO for agricultural water and solar pumping; GSMA/3GPP for mobile IoT; NIST and CISA for device/security and resilience context; EPA for sensor evaluation practice; and original university or institutional research for deployment results. Vendor material may be useful for a product-specific specification but should not define a general rule without corroboration.

  • Check publication/update date when the fact can change.
  • Keep standards/guidelines distinct from illustrative field results.
  • Link to the underlying source so readers can inspect definitions and limitations.

Field evidence

Deployment evidence is attributed to the publishing institution or study. A result from one country, fleet or service model is not generalized into a guaranteed outcome. We extract the operational lesson—such as pairing automated fault data with a repair service—and state the dependencies that may change results elsewhere.

Worked examples

Worked numbers on this site are marked as scenarios. They show how to use a formula or decision rule and are not benchmark values unless a source explicitly establishes them. Readers should replace fleet size, failure rates, thresholds, costs, payload sizes and tolerances with locally observed or project-approved values.

Historical subject evidence

Archived material is used to understand the established subject matter—remote sensing, water, sanitation, energy, groundwater, drought and infrastructure data—but current text is written fresh. Privacy-sensitive former personnel information and contact details are excluded.

Corrections and limitations

No monitoring design can be validated from web research alone. Field coverage, sensor reference checks, site safety, local hydrology, regulations and operating capability must be verified in the deployment. Where a source is older but remains useful for a stable procedure, the page treats it as procedural background rather than as a current market fact.