PI: Colin Everson (University of KwaZulu-Natal)
U.S. Partner: Marek Zreda (University of Arizona)
Project Dates: August 2013 to October 2014
Dr. Colin Everson (right) and a student with the cosmic ray probe at the Baynesfield Estate in KwaZuli-Natal (Photo courtesy Dr. Everson).
This PEER Science project leverages the recent development of the the Cosmic Ray Probe (CRP) as part of a National Science Foundation-supported project. The CRP uses cosmic-ray neutrons to measure soil moisture content over an area of tens of hectares. Dr. Colin Everson and his research team will test the suitability of a cosmic ray moisture probe in providing data for the continued support of soil moisture modeling of South Africa using a hydrologically consistent land surface model, accurate field and satellite-scale estimates of soil moisture for the calibration of hydrometeorogical models, and estimation of the spatial variability of soil moisture at catchment scale.
The researchers plan to build capacity in South Africa by developing a network to extend the cosmic ray moisture probes to multiple applications. Measurements using the probe at area scales of up to 34 hectares has the potential to provide hydrometeorologists with an entirely new way of evaluating surface soil water at spatial scales never achieved with ground-based techniques. This will provide water resource managers, engineers, and agriculturalists with an invaluable but economical new tool to monitor the critical interface between the ground and atmosphere. This new technology can be employed in water demand forecasting and promises to improve the utilization of irrigation water, especially in water scarce regions like South Africa. The probe can also be used for predictive weather and climate models by measuring soil water content. This is currently a major source of uncertainty in weather and climate forecasts, due largely to a lack of suitable observations. The project should also improve the quality of soil moisture data that feed into the South African Flash Flood Guidance System, which provides alerts to the public based on current and predicted rainfall. The system currently uses a relatively crude evaporation model. Therefore, the application of CRP data should help in validating evaporation estimates with better temporal and spatial resolution, thus improving the accuracy of flash flood predictions.
Summary of Recent Activities
The study activities began with a stakeholder workshop at the University of KwaZulu-Natal in Pietermaritzburg. Representatives of the University, the South Africa Water Service, the Agricultural Research Council, and Pegram & Associates, Ltd. were present, and participants heard presentations on hydrological modelling, soil water prediction, and evaporation measurement from satellites. At the workshop, it was suggested that both homogenous and heterogeneous sites should be selected for installation of the cosmic ray moisture probes offering a good degree of sampling variability. The project team ultimately selected two sites within the Baynesfield Estate in KwaZulu-Natal, South Africa for installation of the probes.
It is expected that two cosmic ray probes will be installed at each of two locations at the Baynesfield site. These arrays will be comparison-tested against a network of point-based soil water sensors as well as against networks of sensors on satellites to gauge their respective accuracy. The research team is also planning to attend the 4th COSMOS workshop in Leipzig, Germany in early May 2014. The workshop will focus on cosmic-ray neutron monitoring and scientific applications of the cosmic-ray probe.
Article from website of the University of KwaZulu-Natal (December 2013)
Article from South African Environmental Observation Network newsletter (December 2013)
Article from Farmer's Weekly (January 10, 2014)