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CC BY-NC-ND V4.0, Open Access
Dissertation
SMALL UNMANNED AERIAL SYSTEM BASED REMOTE SENSING TO MAP GEOSPATIAL WATER USE OF FIELD AND PERENNIAL SPECIALTY CROPS
Washington State University
Doctor of Philosophy (PhD), Washington State University
01/2021
DOI:
https://doi.org/10.7273/000005469
Handle:
https://hdl.handle.net/2376/119253
Abstract
Precision irrigation management is critical to optimize the existing consumptive water usage and to balance the ever-increasing food as well as water demand. Therefore, technological advances are needed to better monitor and map the crop water use. Advent of small unmanned aerial systems (UAS) has shown potential to map the crop characteristics at high spatiotemporal resolution. This dissertation explored the application of small UAS based spectral imagery in the visible, near-infrared and longwave thermal infrared wavelengths to map the crop water use (Evapotranspiration [ET] or Transpiration [T]) of the field and perennial crops grown in the Pacific Northwest of the United States. Aerial imagery was acquired at 7 cm/pixel (Multispectral) and 13 cm/pixel (Thermal) and integrated to the modified satellite-standard Mapping ET at High Resolution with Internalized calibration (METRIC). Resulting energy balance model outputs were ET maps for commercially grown potato, spearmint, alfalfa, grapevines, and apple crops. Weather data from nearest automated stations of WSU-AgWeatherNet network was also used as inputs to the energy balance models. UAS-based ET mapping i.e., UASM-ET outperformed conventional satellite-based ET mapping (30 m/pixel) and standard crop-coefficient approaches in mapping spatial heterogeneities in ET. The UASM-ET estimates had strong and significant correlations with the in-situ ET calculations from soil water balance approach with relative deviations within 10% of the latter. The UASM-T maps could capture the impacts of deficit and direct-root-zone drip irrigation of grapevines. The vines irrigated at 100 or 80% of the commercial rates transpired significantly higher than the ones irrigated at 60 and 40% of the commercial rates. Similarly, ET and T was successfully mapped for a high-density apple orchard (cv. Buckeye Gala) throughout the growing season. Evaluated was also the effect of localized and non-localized weather on the apple canopy T estimates. As an alternative to the standard open-field weather stations, the in-situ weather data acquired along different canopy heights could be reliably used for water use quantifications as it can account for localized cropping conditions and management practices. Overall, approaches and data outputs from this dissertation would be useful to growers and crop consultants for site-specific irrigation scheduling and management.
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Details
- Title
- SMALL UNMANNED AERIAL SYSTEM BASED REMOTE SENSING TO MAP GEOSPATIAL WATER USE OF FIELD AND PERENNIAL SPECIALTY CROPS
- Creators
- Abhilash Kumar Chandel
- Contributors
- Lav R. L.R.K. Khot (Advisor)Claudio O. C.O.S. Stöckle (Advisor)R. Troy R.T.P. Peters (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Department of Biological Systems Engineering
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Publisher
- Washington State University
- Number of pages
- 144
- Identifiers
- 99900592257901842
- Language
- English
- Resource Type
- Dissertation