Estimating Rice Yield Loss as a Result of Cold Water
With the heart of the rice growing season upon us, there is no better time to highlight one of our long-standing projects that combines agronomy, remote sensing, and grower relations in the development of original methodologies for accurately and efficiently estimating yield losses from cold water damage.
The California Department of Water Resources (DWR) operates a water storage and delivery system near Oroville, CA. This system stores and distributes water from the Feather River. Among other uses, the stored water is supplied to nearby irrigation and agricultural water districts. These districts are Western Canal Water District, Richvale Irrigation District, Biggs-West Gridley Water District, and the Butte Water District (Districts). Diversion Agreements enabled the supply of water for irrigation from Thermalito Afterbay, a regulating reservoir downstream of Oroville Dam, but did not address crop impacts from cold water.
In 2008, DWR and the Districts negotiated an agreement to resolve all water temperature issues associated with DWR’s past, present, and future water deliveries to the Districts, including any impacts on rice production. This amendment defined how irrigators would be compensated for temperature-impacted rice production.
Beginning with negotiations in 2005 and then implementation in 2008, Land IQ personnel led the development and automation of innovative methods for measuring rice crop yield loss resulting from cold water conditions. This specialized remote sensing approach analyzes nearly 110,000 acres of potential rice production each year for the Districts. The purpose is to provide an accurate estimation of yield loss from cold water by field, such that the compensation provided by DWR to the Districts is equitable, accurate, and economical.
The approach involves remote sensing techniques and algorithms to separate cold water affected areas from other low-yield areas and in-field comparisons of relative rice yield to determine loss. It includes a cooperative working relationship with participating growers who provide their harvest yield monitor information as ground truth training data, which inform state-of-the-art statistical and remote sensing methods. Multiple image dates are used during the analysis to account for both varying planting dates and duplicative field verification. This technically sophisticated approach, based on unique remote sensing methodologies, offers tremendous cost and operational efficiencies relative to ground-based monitoring approaches.
Like many of Land IQ’s projects, ground truth data are critical to our processes. As harvest begins, Land IQ will be collecting yield data with the help of Vantage Sierra Cascade and participating growers. The yield assessment process results in highly accurate rice yield mapping that is ultimately used to determine the distribution of over $1 million annually to the Districts, that in turn provide payments to individual growers.