hydromt_wflow.WflowModel.setup_irrigation#

WflowModel.setup_irrigation(irrigated_area_fn: str | Path | DataArray, irrigation_value: List[int], cropland_class: List[int], paddy_class: List[int] = [], area_threshold: float = 0.6, lai_threshold: float = 0.2)[source]#

Add required information to simulate irrigation water demand.

THIS FUNCTION SHOULD BE RUN AFTER LANDUSE AND LAI MAPS ARE CREATED.

The function requires data that contains information about the location of the irrigated areas (irrigated_area_fn). This, combined with the wflow landuse map that contains classes for cropland (cropland_class) and optionnally for paddy (rice) (``paddy_class), determines which locations are considered to be paddy irrigation, and which locations are considered to be non-paddy irrigation.

Next, the irrigated are map is reprojected to the model resolution, where a threshold (area_threshold) determines when pixels are considered to be classified as irrigation or rainfed cells (both paddy and non-paddy). It adds the resulting maps to the input data.

To determine when irrigation is allowed to occur, an irrigation trigger map is defined. This is a cyclic map, that defines (with a mask) when irrigation is expected to occur. This is done based on the Leaf Area Index (LAI), that is already present in the wflow model configuration. We follow the procedure described by Peano et al. (2019). They describe a threshold value based on the LAI variability to determine the growing season. This threshold is defined as 20% (default value) of the LAI variability, but can be adjusted via the lai_threshold argument.

Adds model layers:

paddy_irrigation_areas: Irrigated (paddy) mask [-]
nonpaddy_irrigation_areas: Irrigated (non-paddy) mask [-]
irrigation_trigger: Map with monthly values, indicating whether irrigation is allowed (1) or not (0) [-]

Parameters:

irrigated_area_fn (str, Path, xarray.DataArray) – Name of the (gridded) dataset that contains the location of irrigated areas.
irrigation_value (list) – List of values that are considered to be irrigated areas in irrigated_area_fn.
cropland_class (list) – List of values that are considered to be cropland in the wflow landuse data.
paddy_class (int) – Class in the wflow landuse data that is considered as paddy or rice. Leave empty if not present (default).
area_threshold (float) – Fractional area of a (wflow) pixel before it gets classified as an irrigated pixel, by default 0.6
lai_threshold (float) – Value of LAI variability to be used to determine the irrigation trigger. By default 0.2.