Illuminating Deep Uncertainties
in the Estimation of Global
Irrigation Water Withdrawals

About DAWN

Irrigation agriculture can boost crop yields with year-round production, but consumes a significant portion of global freshwater resources. In the last decades numerous mathematical models have been developed to precise how much water is withdrawn for crops, as quantification precedes control. But despite the use of ever-powerful computers and finer-grained models, pinpoint accuracy towards the "true" number remains elusive.

The DAWN project contends that this discord reflects deep uncertainties within our understanding of irrigation water use, hidden behind sophisticated algorithms. Rather than intensifying the race for increasingly detailed models, DAWN proposes to bring these uncertainties to the fore as a step towards a more robust understanding of irrigation water use.

DAWN is a Frontier Research Grant project funded by the UKRI Horizon Europe Funding Guarantee (EP/Y02463X/1).

Photo: Irrigation channel in the Oasis of Hassilabied, Morocco. Photo taken by Arnald Puy.

The Team

Arnald Puy

Principal Investigator

Nanxin Wei

Postdoctoral Researcher

Seth Nathaniel Linga

PhD Student

Grace Allen

DAWN Student (2024)

Beatrice Cross

DAWN Student (2024)

Edward Ahmad

DAWN Student (2024)

Ethan Bacon

DAWN Student (2023-2024)

Samuel Flinders

DAWN Student (2023-2024)

Joshua Caulcott-Cooper

DAWN student (2024)

Euan Willis

DAWN Student (2024)

Bethan Callow

DAWN Student (2024)

Naomi Clarke

Sustainability Student (2024)

Michela Massimi


Josh Larsen


Andrea Saltelli


Samuele Lo Piano


Razi Sheikholeslami


José María García Avilés


Bruce Lankford


Ariana Sobhani

DAWN Student (2023)

Emily Murray

DAWN Student (2023)

Latest outputs

May 20, 2024

Are we under a global water crisis?

Arnald Puy and Bruce Lankford critically review the Global Commission on the Economics of Water's claim that society has crossed the upper planetary boundary for water, leading to a global water crisis. Through sensitivity auditing and uncertainty and sensitivity analysis, they suggest that this claim stems from a sweeping narrative marked by disregard for uncertainty and the production of fragile numbers.

January 18, 2024

Paper out in Technometrics

Arnald Puy, Pamphile Roy and Andrea Saltelli propose a simple, easy to understand and computationally efficient approach for global sensitivity analysis based on the concept of discrepancy (the deviation of the distribution of points in a multi-dimensional space from the uniform distribution). The contribution provides modellers with a straightforward tool to conduct global sensitivity analysis.

September 11, 2023

Book chapter on model hubris in Oxford University Press

Arnald Puy and Andrea Saltelli reflect on the philosophical foundations that ground the quest towards ever more detailed models, and identify four practical dangers derived from this pursuit: an explosion of the model’s uncertainty space, model black-boxing, computational exhaustion, and model attachment. The book is edited by Andrea Saltelli and Monica Di Fiore and is published by Oxford University Press.

June 29, 2023

Paper out in Nature Reviews Earth & Environment

In this Comment, Arnald Puy, Michela Massimi, Bruce Lankford and Andrea Saltelli discuss three epistemological obstacles that prevent irrigation models from providing accurate and "objective" estimates: the models’ elusive tie to reality, model plurality and indeterminacy of the target system.

June 8, 2022

DAWN's proof of concept: the delusive accuracy of irrigation water withdrawal estimates

Several modellers, irrigation scientists and experts in uncertainty show in Nature Communications that previous studies on global irrigation water withdrawals might have missed uncertainties spanning two orders of magnitude already at the grid cell level. Current estimates thus present us with a mirage of accuracy.

There are no job offers at the moment.

Contact us

If you are interested in collaborating with DAWN or in becoming a member of the team, please fill in this form or contact us directly below.
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