Data Model

The openyieldtables library uses pydantic to model the data structure.

Raw Data

The underlying data is structured in a way that allows for easy access. The raw data is stored in CSV files and is loaded into the library using the provided models.

The CSV files are structured as follows:

• yield_tables_meta.csv: Contains metadata about the available yield tables.

  • id: The unique identifier of the yield table.
  • title: The name/title of the yield table.
  • country_codes: The ISO 3166-1 alpha-2 country codes of the countries the yield table is applicable to.
  • type: The type of the yield table (e.g. dgz_100).
  • source: The source of the yield table.
  • link: A link to the source of the yield table or the yield table itself.
  • yield_class_step: The step between the yield classes.
  • age_step: The step between the ages.
  • tree_type: The tree type: coniferous or deciduous.

• yield_tables.csv: Contains the yield tables.

  • id: The unique identifier of the yield table.
  • yield_class: The yield class.
  • age: The age in years.
  • dominant_height: The dominant height in m.
  • average_height: The average height in m.
  • dbh: The diameter at breast height in cm.
  • taper: The tree taper.
  • trees_per_ha: The number of trees per hectare.
  • basal_area: The basal area in m2.
  • volume_per_ha: The volume per hectare in vfm.
  • average_annual_age_increment: The average annual increment up to a certain age in volume per hectare vfm.
  • total_growth_performance: The total growth performance in volume per hectare vfm.
  • current_annual_increment: The current annual increment in volume per hectare vfm.
  • mean_annual_increment: The mean annual increment in volume per hectare vfm.

Models

class YieldTableMeta(BaseModel):
    id: int
    title: str
    country_codes: List[str]
    type: Optional[str] = None
    source: str
    link: Optional[str] = None
    yield_class_step: Optional[float] = None
    age_step: Optional[int] = None
    available_columns: List[str]
    tree_type: TreeType

class YieldClassRow(BaseModel):
    age: int
    dominant_height: Optional[float] = None
    average_height: Optional[float] = None
    dbh: Optional[float] = None
    taper: Optional[float] = None
    trees_per_ha: Optional[float] = None
    basal_area: Optional[float] = None
    volume_per_ha: Optional[float] = None
    average_annual_age_increment: Optional[float] = None
    total_growth_performance: Optional[float] = None
    current_annual_increment: Optional[float] = None
    mean_annual_increment: Optional[float] = None

class YieldClass(BaseModel):
    yield_class: Union[int, float]
    rows: List[YieldClassRow]

class YieldTableData(BaseModel):
    yield_classes: List[YieldClass]

class YieldTable(YieldTableMeta):
    data: YieldTableData