OT_220: ORC / AquaLinc (2015), NZ applied-irrigation demand, potato + cabbage

OT_220: ORC / AquaLinc (2015), NZ applied-irrigation demand, potato + cabbage

Source

https://www.orc.govt.nz/media/4499/aqualinc-irrigation-guidelines-2015.pdf — original source (opens in a new tab; the file is not redistributed)

Context: ni · Feeds D02 + D03 (NZ applied-irrigation demand)

Summary

AquaLinc’s modelled reasonable irrigation demand for Otago, retrieved as the NZ cross-check on the model’s applied-irrigation output. It computes demand with FAO-56 crop factors and NIWA climate through a daily soil-water balance (IrriCalc), which is exactly the rigorous method that replaces a flat effective-rain fraction, and it uses the GIS-style regional rainfall the model already holds.

Key claims

- claim: "NZ APPLIED-IRRIGATION DEMAND (potato + cabbage rotation, North Otago, incl. ~5% system loss). Average seasonal applied demand 172-256 mm/yr; 90th-percentile (dry-year) demand 287-395 mm/yr, across rainfall zones from ~550 to ~750 mm mean annual rainfall. Computed with FAO-56 Kc and NIWA VCSN climate via a daily soil-water balance (IrriCalc). This is applied demand (crop ETc minus effective rainfall), i.e. the model's output leg, not the gross CROP_CWR_MM input. [verified against the raw: potato/cabbage + irrigation demand present]"
  source_location: "ORC / AquaLinc (2015), Table 8 (p.26) reasonable irrigation demand; Table 4 crop factors."

Model use

• Validates the applied-irrigation output in D03: the model’s applied_irrigation for arable crops should land near 170-400 mm/yr depending on region and dry-year risk. Its daily soil-water balance (IrriCalc) is the recommended upgrade over the flat effective-rain fraction, and it consumes regional rainfall the model already has from GIS. OT_220

Notes

• Basis. Applied demand (output), not gross CWR (input). Uses FAO-56 Kc, so consistent with OT_218.
• Provenance. ORC / AquaLinc report PDF, authoritative, verified against the raw.

Connections

Links to

EDT domains (2): D02: Smart Food Systems & Agriculture · D03: Water, Waste & Circular Systems

Sources (1): OT_218

Referenced by

Sources (2): OT_219 · OT_221

EDT domains (2): D02: Smart Food Systems & Agriculture · D03: Water, Waste & Circular Systems