Layers preparation
To compute Niva's biodiversity index we need landscape vector layers with some requirements. Here you will find details on each layers and how to build them.
Layers¶
IACS¶
Integrated Administration and Control System (IACS) is a layer that contain crop plots. The informations needed from this layer are:
- Crop plots geometries as polygons.
- NIVA ID for crops (Can be mapped using Map Niva ID processing algorithm).
The final IACS layer it's a polygon layer with at least the field 'Niva.ID':
| Niva.ID |
|---|
| 35 |
| 3 |
| 7 |
| 41 |
| 25 |
| ... |
Artificial¶
Artificial is a layer that contains multiple landscape elements that are considered as impermeable. This layer shall have a field "NATURE" that display the nature of the elements (i.e. building, train line...). For buildings the 'NATURE' field should be exactly 'building' as this value will be used to extract buildings geometries and apply specific processing (computation of an area of effect).
This layer is a polygon layer and to convert elements that are not polygons we apply a buffer with a distance that vary depending on the element. In the table below we describe the rules we used for buffer distance depending on each kind of elements that are not polygons (point or line).
Artificial elements
| Name | Description | Buffer distance |
|---|---|---|
| Pylons | Pylons | \(0.5m\) |
| Linear structures | bridges, wall, fence, tunnel.. | \(0.5m\) |
| Isolated structures | Landscape cross, bell tower.. | \(0.5m\) |
| Dams | Dams | \(0.5m\) |
| Wind turbines | Wind turbines | \(2.5m\) |
| Isolated structures | All isolated structures which are not wind turbines | \(0.5m\) |
| Train lines | Train lines | \(1.25m * \text{number of lanes}\) |
| Routes | Road, trail, stones road, highway... | Describe below |
For route features, If the feature contain width information this width will be used for buffer distance. For features without width information buffer distance is:
- Mean of width for all features of this route type in the region of interest.
- Default values if no features of this type have width information for the region of interest. Exemples of what we used in the table below:
| Type | Default buffer distance |
|---|---|
| Country lane | \(0.5m\) |
| Stairs | \(0.5m\) |
| Cycle path | \(1m\) |
| Trail | \(0.5m\) |
| stones road | \(2m\) |
| Single-carriageway road | \(4.2m\) |
| Double-carriageway road | \(4.8m\) |
| Highway | \(9.5m\) |
The final Artificial layer it's a polygon layer with at least the field 'NATURE':
| NATURE |
|---|
| pylon |
| building |
| wind turbines |
| country lane |
| ... |
Non Agricultural Areas (Optionnal)¶
Non agricultural areas (NAA) is a layer that contain surfaces which are not agricultural in the landascape. Mainly is vegetation & trees especially within or between crop plots. These elements should be polygons except isolated tree on which we apply a buffer of \(3m\).
Niva's biodiversity index can also be computed without NAA layer as these data can be difficult to obtain. The result will be less precise but more easy and fast to compute.
The final NAA layer it's a polygon layer with no specific field required.