State Water Resources Research Institute Program
Project Id: 2010OK184B
Title: Drought monitoring: a system for tracking plant available soil moisture based on the Oklahoma Mesonet
Project Type: Research
Start Date: 3/01/2010
End Date: 2/28/2011
Congressional District: 3
Focus Categories: None
Keywords: drought, soil moisture, Mesonet
Principal Investigators: Ochsner, Tyson; Basara, Jeffrey; Fiebrich, Chris; Sutherland, Albert (Oklahoma State University)
Federal Funds: $ 25,000
Non-Federal Matching Funds: $ 50,000
Abstract: Real-time drought monitoring is essential for early detection and adaptive management to mitigate the negative impacts of drought on the people, economy, and ecosystems of Oklahoma. Drought impacts can be severe. For example, the 2006 drought cost the state's economy over $500 million from lost crop production alone. While drought monitoring is critical to Oklahoma's resource managers, it is hampered by a lack of data on a crucial drought indicator: plant available water. Crop yield losses and, by extension, the economic impacts of drought, are strongly linked to plant available water (i.e. the amount of soil moisture which is available for plant uptake). Cumulative rainfall data alone are poor predictors of drought impacts, because costly short term soil moisture deficits can occur in years of average or above average rainfall. At the first signs of drought, resource managers need reliable information on the available reserves of soil moisture to enable effective adaptations (e.g. crop marketing contracts, cattle stocking rates, hay purchases, fertilizer rate adjustments).
This need can be met by building upon the existing capabilities of the Oklahoma Mesonet. The Mesonet is the world's leading automated weather station network providing continuous, real-time data from 120 locations across the state. These stations possess existing soil moisture sensors but offer no measure of plant available water. The plant available water depends, not only on the soil moisture, but also on site-specific properties of the soil. We propose to collect soil samples from every Mesonet site, to measure the essential soil properties governing plant water availability, and to use the resulting information to create the world's first statewide automated monitoring system for plant available water.
Project objectives and methods
The objective of this proposal is to improve drought monitoring in Oklahoma through the development of a Mesonet-based system for tracking plant available water. The specific aims are: (1) to measure the soil properties controlling the plant availability of soil moisture, (2) to develop a routine to calculate plant available water by integrating the sensor output and the site-specific soil properties, and (3) in a future funding cycle, to test and release an operational plant available water map for the Oklahoma Mesonet.
Results and benefits
This monitoring system will provide resource managers with reliable information on the remaining reserves of plant available water enabling them to adapt their management strategies. For example, by knowing early that plant available water is approaching critical minimum values, farmers could reduce mid-season N fertilizer application rates on wheat, change forward contracting strategies, or choose to graze out more wheat. Similarly, ranchers, facing the potential for reduced pasture, could make early arrangements to purchase hay or could sell cattle early, when prices are more favorable. Further, government agencies, such as the Oklahoma Water Resources Board, could gain a clearer picture of the extent and distribution of drought effects in the state and could target relief efforts more effectively.
Progress/Completion Report, 2010, PDF
Progress/Completion Report, 2011, PDF