# HALOWERK Southern Land – Portugal Drainage Tendency

> HALOWERK Southern Land – Portugal Drainage Tendency is a paid API for AI agents from suedland.halowerk.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-15).

Returns the relative runoff tendency for a geographic point in Portugal, derived from terrain slope and surface ruggedness using DEM analysis.

## Facts

- Endpoint: POST https://suedland.halowerk.com/v1/pt-drainage-tendency
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/halowerk-southern-land-portugal-drainage-tendency-691dec0c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_FmoPS6JrMhSD6Z6DqWweQ

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability halowerk-southern-land-portugal-drainage-tendency-691dec0c -d '<json body>'
```

Example prompt: What's the drainage tendency at latitude 38.7, longitude -9.1 in Portugal — I need to know how prone that land is to runoff based on its slope and ruggedness.

## When to prefer this

Use this endpoint when you need a quick, point-based runoff tendency estimate for a location in Portugal and terrain slope plus ruggedness are the relevant factors. Prefer it over general GIS tools when you need a pay-per-call, API-accessible scalar metric without managing raster datasets. Particularly useful in land assessment workflows combining multiple HALOWERK Southern Land signals (e.g. soil texture, elevation SD, crop cover) for the same Portuguese coordinate.

## Known failure modes

- Coordinate outside Portugal boundary — rejected with a validation error before payment is charged
- Latitude or longitude out of the published European coverage range (lat 34–72.5, lon -31.5–40.5) — schema validation error
- Non-numeric or malformed coordinate values — input validation failure
- Service unavailable or upstream DEM data error — 5xx response

## How this service works

Relative runoff tendency derived from slope and ruggedness. The coordinate is validated against the Natural Earth boundary for Portugal; results outside it are rejected before payment.

## Output

A numeric index representing the relative runoff tendency at the queried location, derived from terrain slope and surface ruggedness. Coordinates outside the Natural Earth boundary for Portugal are rejected before any payment is processed.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "latitude": {
   "type": "number",
   "maximum": 72.5,
   "minimum": 34,
   "description": "WGS84 latitude inside the published European coverage."
  },
  "longitude": {
   "type": "number",
   "maximum": 40.5,
   "minimum": -31.5,
   "description": "WGS84 longitude inside the published European coverage."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/halowerk-southern-land-portugal-drainage-tendency-691dec0c/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from suedland.halowerk.com](https://www.zero.xyz/host/suedland.halowerk.com/llms.txt)