Forest Flows

Forest Flows is a five year research programme (September 2019 to September 2024) focusing on forest hydrology. 


Lead by Scion throught the MBIE-supported programme, the Forest Flows is a New Zealand project focusing on developing methods to predict and optimise water use and supply in planted forests to answer the questions: 

Where is the water?

Where is it going?

And who gets to use it?


Understanding how water flows through the land, including planted forests is essential to make the best use of land and water while maintaining environmental health. New research is needed to replace outdated models and understand the complex processes of how water is distributed, used and circulated in forested catchments.

Datalogger station in Southern Kaingaroa Forest that is collecting tree stem growth and water use measurements in real time from 48 individual trees.

Research aims

The programme aims to create a biophysical model of forest hydrology that accurately predicts water storage and release for entire catchments, while also providing data on changes in water quality over time.

This programme will:

  • Identify key forest hydrological processes by combining monitoring of soil-plant-atmosphere interactions with a range of targeted ground-based research over the long-term.
  • Develop and use remote-sensing tools, to collect data that spans catchments and forests and can be linked to key forest hydrological processes.
  • Create a model that predicts hydrological flow across a range of NZ planted forests.
  • Create an decision making framework that provides the necessary information to optimise water use in planted forests.

We will achieve this through three Impact Areas (IAs):

  • Quantifying water processes within a forested catchment
  • Spatially quantify forest water flux and storage at different scales with novel remote-sensing technology
  • Develop and apply an assessment framework for the environmental, socioeconomic, and cultural impacts of planted forests on downstream water ecosystem services

Using novel technology

This programme will allow us to develop a hydrology model from data collected on water use, storage and movement, at tree, stand and forest scales. To bridge these different scales, we will combine data from continuous on-site

monitoring with remote sensing. The remote sensing will include a novel P-band radar method, which uses microwaves to penetrate the ground and measure variation in soil moisture levels.

Technology to be used includes:

  • L- and P-Band synthetic aperture radar
  • Hyperspectral imaging
  • LiDAR
  • 18O stable isotope sampling
  • Continuous water nitrate measurements
  • Soil apparent electrical conductivity
  • Ground penetrating radar
  • Wireless meshed sensor networks providing real time spatial and temporal water quantity and quality data
  • Integrated data collection of water movement and storage throughout forested catchments through to streams and groundwater
  • Real time measurements of tree growth and water use for multiple species
  • Data fusion of terrestrial and remote sensing data

Optimising water use in planted forests

The hydrology model generated in this programme will include information on water use for different tree species and genotypes. Improved understanding of water flows in planted forests will allow us to develop a tool to optimise water


Improved models of water flows will also allow us to identify and plan for the benefits that afforestation can provide to downstream users, including stormflow modification, low-flow water supply and improved water quality


New Zealand-based collaborators include

International collaborators include