Application of Landsat to Evaluate Effects of Irrigation Forbearance

Richard Cuenca,Yutaka Hagimoto,Shannon Ciotti

doi:10.3390/rs5083776

Richard Cuenca, Yutaka Hagimoto + Show 1 more

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https://doi.org/10.3390/rs5083776

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Abstract

Thirty-meter resolution Landsat data were used to evaluate the effects of irrigation management in the Wood River Valley, Upper Klamath Basin, Oregon. In an effort to reduce water use and leave more of the water resource in-stream, 4,674 ha of previously flood irrigated pasture was managed as dryland pasture. Ground-based measurements over one irrigated and one unirrigated pasture site were used to monitor the difference in evapotranspiration (ET) using the Bowen ratio-energy balance method. These data sets represent point measurements of the response to irrigation, but do not allow for the spatial integration of effects of irrigated versus unirrigated land treatment. Four Landsat scenes of the Wood River Valley during the 2004 growing season were evaluated using reconstructed METRIC algorithms. Comparisons of ET algorithm output with ground-based data for all components of the energy balance, including net radiation, soil heat flux, sensible heat flux and evapotranspiration, were made for the four scenes. The excellent net radiation estimates, along with reasonable estimates of the other components, are demonstrated along with the capability to integrate results to the basin scale.

Highlights

The most immediately notable result of the comparison is the close agreement in the net radiation component of the energy balance for both the irrigated and unirrigated sites
Differences between measured and computed sensible heat flux can be significant, e.g., July at the unirrigated site and June at the irrigated site
These wet conditions mean that the range of surface temperatures between the “hot” and “cold” pixels needed for the iterative scheme to compute the sensible heat flux is very limited

Summary

Introduction

The headwaters of the Klamath Basin in Oregon and northern California are in an agricultural region with extensive irrigation for livestock and crop production. The primary hydrologic feature in the Upper Klamath Basin is 250 km Upper Klamath Lake, including connected Agency Lake which drains into the Upper Klamath Lake. The U.S Bureau of Reclamation (USBR) manages lake levels to support two endangered species of Suckers, releases water to the mainstem Klamath River which supports endangered Coho salmon, and provides irrigation water to thousands of farms and ranches in the Klamath Project (see Figure 1). California and Oregon; (b) Aerial view of Wood River Valley which extends from. The Klamath Project was the first irrigation project undertaken by USBR.

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