A 500-m crop water requirement and irrigation water demand dataset for 25 crop types in the Yellow River Basin (2000–2020)

This dataset provides high-resolution (500 m, ~0.00417°) annual estimates of crop water requirement (CWR) and irrigation water demand (IWD) for 25 crop types in the Yellow River Basin (YRB), China, spanning 2000 to 2020. CWR is defined as crop evapotranspiration minus effective precipitation over the growing season (equivalent to the net irrigation water requirement in FAO-56 terminology), representing the water deficit that must be supplied through irrigation. IWD is defined as CWR divided by the irrigation water use efficiency coefficient (IWUEC), representing the gross water that must be withdrawn to meet crop water needs after accounting for conveyance and application losses.
The dataset was produced using the FAO Penman-Monteith approach with spatially explicit crop coefficients (Kc) interpolated from 45 observation stations and spatiotemporally dynamic provincial-level IWUEC values. Cropland spatial distribution is based on the GLAD 30-m global cropland dataset, selected as the optimal product after systematic evaluation of eight remote sensing-based cropland datasets against statistical records from 135 administrative units. Crop-specific sown areas were compiled from provincial statistical yearbooks across 170 administrative units (counties and prefectures) and spatially allocated to 500-m cropland pixels.

Two complementary versions are provided:

• Sown area-based version (CWR and IWD): Covers all cropland including rainfed areas, reflecting the full theoretical agricultural water gap. Multi-year average CWR and IWD are 548.3 × 10⁸ m³ and 1086.8 × 10⁸ m³, respectively.
• Irrigated area-based version (CWR-AIA and IWD-AIA): Constrained by actual irrigation extent using the CIrrMap250 annual irrigated cropland maps, reflecting practical irrigation demand. Multi-year average CWR-AIA and IWD-AIA are 258.6 × 10⁸ m³ and 508.4 × 10⁸ m³, respectively.

Spatial and Temporal Coverage

• Spatial extent: Yellow River Basin, China (95°53'–119°05'E, 32°10'–41°50'N), approximately 795,000 km²
• Spatial resolution: ~500 m (0.00417°)
• Coordinate reference system: WGS84 (EPSG:4326)
• Temporal coverage: 2000–2020 (annual)

Crop Types

The dataset covers the following 25 crop types: spring maize, summer maize, spring wheat, winter wheat, rice, beet, coarse cereals, cotton, flax, fruits, green fodder, melons and gourds, millet, oil crops, peanut, potato, rapeseed, sesame, sorghum, spring soybean, summer soybean, sunflower seed, sweet potato, tubers, and vegetables.

File Structure

The dataset is organized into four ZIP archives, each corresponding to one variable:

• CWR.zip:Crop water requirement based on total sown area (mm/yr per pixel)
• IWD.zip:Irrigation water demand based on total sown area (mm/yr per pixel)
• CWR-AIA.zip:Crop water requirement adjusted for actual irrigated area (mm/yr per pixel)
• IWD-AIA.zip:Irrigation water demand adjusted for actual irrigated area (mm/yr per pixel

File naming follows the convention:

• CWR_YYYY_Crop_name.tif (sown area-based crop water requirement)
• IWD_YYYY_Crop_name.tif (sown area-based irrigation water demand)
• CWR-AIA_YYYY_Crop_name.tif (irrigated area-adjusted crop water requirement)
• IWD-AIA_YYYY_Crop_name.tif (irrigated area-adjusted irrigation water demand)

where YYYY represents the year (2000–2020) and Crop_name indicates the crop type.