# Sand Content (%) (100–200 cm) (`SNDPPT_M_sl7_1km_ll`) — EDIS AI Agent Dataset View

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## 1. Dataset Metadata
- **Raster Name**: Sand Content (%) (100–200 cm)
- **Slug**: `SNDPPT_M_sl7_1km_ll`
- **Units**: `% fine earth`
- **Spatial Extent**: UL(83.9991672, -180.0) to LR(-56.0008328, 180.0)
- **Summary**: Percentage of **sand particles** in the soil fine earth fraction. Sand particles are mineral particles with diameters typically between **0.05 mm and 2.0 mm**.
- **Included in Flagship Map Package**: `Global_ISO9223_2020_2024_LE_V4` (`GET https://secure.engineeringdirector.com/api/bundles/Global_ISO9223_2020_2024_LE_V4/point_query`)

### Color Table & Value Breaks
- `(0.0, (92.0, 51.0, 23.0))`
- `(0.5, (93.8, 52.1, 23.7))`
- `(1.0, (95.6, 53.2, 24.4))`
- `(1.5, (97.4, 54.3, 25.1))`
- `(2.0, (99.2, 55.4, 25.8))`
- `(2.5, (101.0, 56.5, 26.5))`
- `(3.0, (102.8, 57.6, 27.2))`
- `(3.5, (104.6, 58.7, 27.9))`
- `(4.0, (106.4, 59.8, 28.6))`
- `(4.5, (108.2, 60.9, 29.3))`
- `(5.0, (110.0, 62.0, 30.0))`
- `(5.0, (110.0, 62.0, 30.0))`

# SNDPPT_M_sl7_1km_ll.tif — Technical Specification and Citation

## Parameter Name
- **SNDPPT**  
- **Definition:** Sand Content Percentage

## Description
Percentage of **sand particles** in the soil fine earth fraction. Sand particles are mineral particles with diameters typically between **0.05 mm and 2.0 mm**.

This parameter describes soil texture characteristics and strongly influences drainage, permeability, aeration, and electrical resistivity behavior.

## Units
- **% (percent by mass of fine earth fraction)**  
  - Range: **0–100**

## Depth Level
- **sl7 (Soil Layer 7)**  
- Depth interval: **100–200 cm**

## Data Source
- **ISRIC SoilGrids**
- Based on:
  - WoSIS (World Soil Information Service)  
  - Machine learning models (e.g., Random Forest)

## Spatial Characteristics
- **Coverage:** Global (typically excludes Antarctica)  
- **Resolution:** 1 km  
- **Coordinate System:** WGS84 (EPSG:4326)  
- **Grid Type:** Latitude/Longitude (ll)

## File Naming Convention
`SNDPPT_M_sl7_1km_ll.tif`

### Components
- **SNDPPT** = Variable (Sand percentage)  
- **M** = Mean prediction (also available: Q05, Q95 for uncertainty)  
- **sl7** = Depth layer (100–200 cm)  
- **1km** = Spatial resolution  
- **ll** = Geographic coordinate grid (latitude/longitude)  

## ISRIC Metadata Alignment
- **Variable Name:** Sand content in %  
- **Attribute Title:** Sand content in % at depth 1.00 m  
- **Range Domain:** 0 to 100  

## Typical Value Range
- **0 to 100 %**

| Value | Interpretation |
|------|--------------|
| 0–20% | Low sand content / clay-rich soils |
| 20–50% | Moderate sand content |
| 50–80% | Sandy soils |
| >80% | Very sandy soils |

## Important Clarification
- **100–200 cm = depth interval (sl7)**  
- **0–100 = actual raster value range (%)**  
- Values represent **sand percentage within the fine earth fraction** (<2 mm particles)  

## Recommended Citation

### Primary Scientific Citation
> Poggio, L., de Sousa, L.M., Batjes, N.H., et al. (2021).  
> *SoilGrids 2.0: producing soil information for the globe with quantified spatial uncertainty*.  
> **SOIL**, 7, 217–240.  
> https://doi.org/10.5194/soil-7-217-2021  

### Data Citation
> ISRIC – World Soil Information (2020).  
> *SoilGrids250m: Global gridded soil information*.  
> https://soilgrids.org  

### Example Usage Citation
> Sand content data (SNDPPT, 100–200 cm) obtained from ISRIC SoilGrids (1 km resolution).

## Notes for Advanced Use
- High sand content generally results in:
  - Higher permeability  
  - Lower water retention  
  - Higher oxygen diffusion  
  - Increased electrical resistivity  
- Important for:
  - Soil resistivity modeling  
  - Corrosion prediction models  
  - Drainage and infiltration analysis  
  - Soil texture classification  
- Commonly evaluated alongside:
  - Clay content (CLYPPT)  
  - Silt content (SLTPPT)  
  - Bulk density (BLDFIE)  

---

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```bash
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```

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